Re: [Discuss][Java] 64-bit lengths for ValueVectors
I'll also note this isn't quite in final form, I'd still like to add some more unit tests. On Fri, Nov 22, 2019 at 11:36 AM Wes McKinney wrote: > hi Micah -- it makes sense to limit the scope for the time being to > permitting LargeString/Binary work to proceed. Jacques, have you had a > chance to look at this? > > On Fri, Nov 15, 2019 at 3:07 AM Micah Kornfield > wrote: > > > > Apologies for the long delay, I chose to do the minimal work of limiting > this change [1] to allowing ArrowBuf to 64-bit lengths. This would unblock > work on LargeString and LargeBinary. If this change looks OK, I think > there is some follow-up work to add more thorough unit/integration tests. > > > > As an aside, it does seem like the 2GB limit is affecting some users in > Spark [2][3], so hopefully LargeString would help with this. > > > > Allowing more than MAX_INT elements is Vectors/array still a blocker for > making LargeList useful. > > > > Thanks, > > Micah > > > > [1] https://github.com/apache/arrow/pull/5020 > > [2] > https://stackoverflow.com/questions/58739888/spark-is-it-possible-to-increase-pyarrow-buffer#comment103812119_58739888 > > [3] https://issues.apache.org/jira/browse/ARROW-4890 > > > > On Fri, Aug 23, 2019 at 8:33 AM Jacques Nadeau > wrote: > >> > >> > >> > >> On Fri, Aug 23, 2019, 8:55 PM Micah Kornfield > wrote: > > The vector indexes being limited to 32 bits doesn't limit the > addressing to 32 bit chunks of memory. For example, you're prime example > before was image data. Having 2 billion images of 1mb images would still be > supported without changing the index addressing. > >>> > >>> This might be pre-coffee math, but I think we are limited to > approximately 2000 images because an ArrowBuf only holds up-to 2 billion > bytes [1]. While we have plenty of room for the offsets, we quickly run > out of contiguous data storage space. For LargeString and LargeBinary this > could be fixed by changing ArrowBuf. > >>> > >>> LargeArray faces the same problem only it applies to its child > vectors. Supporting LargeArray properly is really what drove the > large-scale interface change. > >> > >> > >> My expressed concern about these changes was specifically about the use > of long for get/set in the vector interfaces. I'm not saying that we > constrain memory/ArrowBufs to 32bits. > >> > >>> > Rebase would help if possible. > >>> > >>> I'll try to get to this in the next few days. > >>> > >>> [1] > https://github.com/apache/arrow/blob/95175fe7cb8439eebe6d2f6e0495f551d6864380/java/memory/src/main/java/io/netty/buffer/ArrowBuf.java#L164 > >>> > >>> On Fri, Aug 23, 2019 at 4:55 AM Jacques Nadeau > wrote: > > > > On Fri, Aug 23, 2019, 11:49 AM Micah Kornfield > wrote: > >> > >> I don't think we should couple this discussion with the > implementation of large list, etc since I think those two concepts are > independent. > > > > I'm still trying to balance in my mind which is a worse experience > for consumers of the libraries for these types. Claiming that Java > supports these types but throwing an exception when the Vectors exceed > 32-bits or just say they aren't supported until we have 64-bit support in > Java. > > > The vector indexes being limited to 32 bits doesn't limit the > addressing to 32 bit chunks of memory. For example, you're prime example > before was image data. Having 2 billion images of 1mb images would still be > supported without changing the index addressing. > > > > > >> > >> I've asked some others on my team their opinions on the risk here. > I think we should probably review some our more complex vector interactions > and see how the jvm's assembly changes with this kind of change. Using > microbenchmarking is good but I think we also need to see whether we're > constantly inserting additional instructions or if in most cases, this > actually doesn't impact instruction count. > > > > > > Is this something that your team will take on? > > > > Yeah, we need to look at this I think. > > > Do you need a rebased version of the PR or is the existing one > sufficient? > > > Rebase would help if possible. > > > > > > Thanks, > > Micah > > > > On Thu, Aug 22, 2019 at 8:56 PM Jacques Nadeau > wrote: > >> > >> I don't think we should couple this discussion with the > implementation of large list, etc since I think those two concepts are > independent. > >> > >> I've asked some others on my team their opinions on the risk here. > I think we should probably review some our more complex vector interactions > and see how the jvm's assembly changes with this kind of change. Using > microbenchmarking is good but I think we also need to see whether we're > constantly inserting additional instructions or if in most cases, this > actually doesn't impact instruction count. > >> > >> > >> > >>
Re: [Discuss][Java] 64-bit lengths for ValueVectors
hi Micah -- it makes sense to limit the scope for the time being to permitting LargeString/Binary work to proceed. Jacques, have you had a chance to look at this? On Fri, Nov 15, 2019 at 3:07 AM Micah Kornfield wrote: > > Apologies for the long delay, I chose to do the minimal work of limiting this > change [1] to allowing ArrowBuf to 64-bit lengths. This would unblock work > on LargeString and LargeBinary. If this change looks OK, I think there is > some follow-up work to add more thorough unit/integration tests. > > As an aside, it does seem like the 2GB limit is affecting some users in Spark > [2][3], so hopefully LargeString would help with this. > > Allowing more than MAX_INT elements is Vectors/array still a blocker for > making LargeList useful. > > Thanks, > Micah > > [1] https://github.com/apache/arrow/pull/5020 > [2] > https://stackoverflow.com/questions/58739888/spark-is-it-possible-to-increase-pyarrow-buffer#comment103812119_58739888 > [3] https://issues.apache.org/jira/browse/ARROW-4890 > > On Fri, Aug 23, 2019 at 8:33 AM Jacques Nadeau wrote: >> >> >> >> On Fri, Aug 23, 2019, 8:55 PM Micah Kornfield wrote: The vector indexes being limited to 32 bits doesn't limit the addressing to 32 bit chunks of memory. For example, you're prime example before was image data. Having 2 billion images of 1mb images would still be supported without changing the index addressing. >>> >>> This might be pre-coffee math, but I think we are limited to approximately >>> 2000 images because an ArrowBuf only holds up-to 2 billion bytes [1]. >>> While we have plenty of room for the offsets, we quickly run out of >>> contiguous data storage space. For LargeString and LargeBinary this could >>> be fixed by changing ArrowBuf. >>> >>> LargeArray faces the same problem only it applies to its child vectors. >>> Supporting LargeArray properly is really what drove the large-scale >>> interface change. >> >> >> My expressed concern about these changes was specifically about the use of >> long for get/set in the vector interfaces. I'm not saying that we constrain >> memory/ArrowBufs to 32bits. >> >>> Rebase would help if possible. >>> >>> I'll try to get to this in the next few days. >>> >>> [1] >>> https://github.com/apache/arrow/blob/95175fe7cb8439eebe6d2f6e0495f551d6864380/java/memory/src/main/java/io/netty/buffer/ArrowBuf.java#L164 >>> >>> On Fri, Aug 23, 2019 at 4:55 AM Jacques Nadeau wrote: On Fri, Aug 23, 2019, 11:49 AM Micah Kornfield wrote: >> >> I don't think we should couple this discussion with the implementation >> of large list, etc since I think those two concepts are independent. > > I'm still trying to balance in my mind which is a worse experience for > consumers of the libraries for these types. Claiming that Java supports > these types but throwing an exception when the Vectors exceed 32-bits or > just say they aren't supported until we have 64-bit support in Java. The vector indexes being limited to 32 bits doesn't limit the addressing to 32 bit chunks of memory. For example, you're prime example before was image data. Having 2 billion images of 1mb images would still be supported without changing the index addressing. > >> >> I've asked some others on my team their opinions on the risk here. I >> think we should probably review some our more complex vector >> interactions and see how the jvm's assembly changes with this kind of >> change. Using microbenchmarking is good but I think we also need to see >> whether we're constantly inserting additional instructions or if in most >> cases, this actually doesn't impact instruction count. > > > Is this something that your team will take on? Yeah, we need to look at this I think. > Do you need a rebased version of the PR or is the existing one sufficient? Rebase would help if possible. > > Thanks, > Micah > > On Thu, Aug 22, 2019 at 8:56 PM Jacques Nadeau wrote: >> >> I don't think we should couple this discussion with the implementation >> of large list, etc since I think those two concepts are independent. >> >> I've asked some others on my team their opinions on the risk here. I >> think we should probably review some our more complex vector >> interactions and see how the jvm's assembly changes with this kind of >> change. Using microbenchmarking is good but I think we also need to see >> whether we're constantly inserting additional instructions or if in most >> cases, this actually doesn't impact instruction count. >> >> >> >> On Wed, Aug 21, 2019 at 12:18 PM Micah Kornfield >> wrote: With regards to the reference implementation point. It is a good point. I'm on vacation
Re: [Discuss][Java] 64-bit lengths for ValueVectors
I think the 2GB limit is overly restrictive for modern computers. This is a problem we must face anyway. Best, Liya Fan On Fri, Nov 15, 2019 at 5:07 PM Micah Kornfield wrote: > Apologies for the long delay, I chose to do the minimal work of limiting > this change [1] to allowing ArrowBuf to 64-bit lengths. This would unblock > work on LargeString and LargeBinary. If this change looks OK, I think > there is some follow-up work to add more thorough unit/integration tests. > > As an aside, it does seem like the 2GB limit is affecting some users in > Spark [2][3], so hopefully LargeString would help with this. > > Allowing more than MAX_INT elements is Vectors/array still a blocker for > making LargeList useful. > > Thanks, > Micah > > [1] https://github.com/apache/arrow/pull/5020 > [2] > https://stackoverflow.com/questions/58739888/spark-is-it-possible-to-increase-pyarrow-buffer#comment103812119_58739888 > [3] https://issues.apache.org/jira/browse/ARROW-4890 > > On Fri, Aug 23, 2019 at 8:33 AM Jacques Nadeau wrote: > >> >> >> On Fri, Aug 23, 2019, 8:55 PM Micah Kornfield >> wrote: >> >>> The vector indexes being limited to 32 bits doesn't limit the addressing to 32 bit chunks of memory. For example, you're prime example before was image data. Having 2 billion images of 1mb images would still be supported without changing the index addressing. >>> >>> This might be pre-coffee math, but I think we are limited to >>> approximately 2000 images because an ArrowBuf only holds up-to 2 billion >>> bytes [1]. While we have plenty of room for the offsets, we quickly run >>> out of contiguous data storage space. For LargeString and LargeBinary this >>> could be fixed by changing ArrowBuf. >>> >>> LargeArray faces the same problem only it applies to its child vectors. >>> Supporting LargeArray properly is really what drove the large-scale >>> interface change. >>> >> >> My expressed concern about these changes was specifically about the use >> of long for get/set in the vector interfaces. I'm not saying that we >> constrain memory/ArrowBufs to 32bits. >> >> >>> Rebase would help if possible. >>> >>> I'll try to get to this in the next few days. >>> >>> [1] >>> https://github.com/apache/arrow/blob/95175fe7cb8439eebe6d2f6e0495f551d6864380/java/memory/src/main/java/io/netty/buffer/ArrowBuf.java#L164 >>> >>> On Fri, Aug 23, 2019 at 4:55 AM Jacques Nadeau >>> wrote: >>> On Fri, Aug 23, 2019, 11:49 AM Micah Kornfield wrote: > I don't think we should couple this discussion with the implementation >> of large list, etc since I think those two concepts are independent. > > I'm still trying to balance in my mind which is a worse experience for > consumers of the libraries for these types. Claiming that Java supports > these types but throwing an exception when the Vectors exceed 32-bits or > just say they aren't supported until we have 64-bit support in Java. > The vector indexes being limited to 32 bits doesn't limit the addressing to 32 bit chunks of memory. For example, you're prime example before was image data. Having 2 billion images of 1mb images would still be supported without changing the index addressing. > >> I've asked some others on my team their opinions on the risk here. I >> think we should probably review some our more complex vector interactions >> and see how the jvm's assembly changes with this kind of change. Using >> microbenchmarking is good but I think we also need to see whether we're >> constantly inserting additional instructions or if in most cases, this >> actually doesn't impact instruction count. > > > Is this something that your team will take on? > Yeah, we need to look at this I think. Do you need a rebased version of the PR or is the existing one > sufficient? > Rebase would help if possible. > Thanks, > Micah > > On Thu, Aug 22, 2019 at 8:56 PM Jacques Nadeau > wrote: > >> I don't think we should couple this discussion with the >> implementation of large list, etc since I think those two concepts are >> independent. >> >> I've asked some others on my team their opinions on the risk here. I >> think we should probably review some our more complex vector interactions >> and see how the jvm's assembly changes with this kind of change. Using >> microbenchmarking is good but I think we also need to see whether we're >> constantly inserting additional instructions or if in most cases, this >> actually doesn't impact instruction count. >> >> >> >> On Wed, Aug 21, 2019 at 12:18 PM Micah Kornfield < >> emkornfi...@gmail.com> wrote: >> >>> With regards to the reference implementation point. It is a good point. I'm on vacation this week. Unless you're pushing hard on this,
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Apologies for the long delay, I chose to do the minimal work of limiting this change [1] to allowing ArrowBuf to 64-bit lengths. This would unblock work on LargeString and LargeBinary. If this change looks OK, I think there is some follow-up work to add more thorough unit/integration tests. As an aside, it does seem like the 2GB limit is affecting some users in Spark [2][3], so hopefully LargeString would help with this. Allowing more than MAX_INT elements is Vectors/array still a blocker for making LargeList useful. Thanks, Micah [1] https://github.com/apache/arrow/pull/5020 [2] https://stackoverflow.com/questions/58739888/spark-is-it-possible-to-increase-pyarrow-buffer#comment103812119_58739888 [3] https://issues.apache.org/jira/browse/ARROW-4890 On Fri, Aug 23, 2019 at 8:33 AM Jacques Nadeau wrote: > > > On Fri, Aug 23, 2019, 8:55 PM Micah Kornfield > wrote: > >> The vector indexes being limited to 32 bits doesn't limit the addressing >>> to 32 bit chunks of memory. For example, you're prime example before was >>> image data. Having 2 billion images of 1mb images would still be supported >>> without changing the index addressing. >> >> This might be pre-coffee math, but I think we are limited to >> approximately 2000 images because an ArrowBuf only holds up-to 2 billion >> bytes [1]. While we have plenty of room for the offsets, we quickly run >> out of contiguous data storage space. For LargeString and LargeBinary this >> could be fixed by changing ArrowBuf. >> >> LargeArray faces the same problem only it applies to its child vectors. >> Supporting LargeArray properly is really what drove the large-scale >> interface change. >> > > My expressed concern about these changes was specifically about the use of > long for get/set in the vector interfaces. I'm not saying that we constrain > memory/ArrowBufs to 32bits. > > >> Rebase would help if possible. >> >> I'll try to get to this in the next few days. >> >> [1] >> https://github.com/apache/arrow/blob/95175fe7cb8439eebe6d2f6e0495f551d6864380/java/memory/src/main/java/io/netty/buffer/ArrowBuf.java#L164 >> >> On Fri, Aug 23, 2019 at 4:55 AM Jacques Nadeau >> wrote: >> >>> >>> >>> On Fri, Aug 23, 2019, 11:49 AM Micah Kornfield >>> wrote: >>> I don't think we should couple this discussion with the implementation > of large list, etc since I think those two concepts are independent. I'm still trying to balance in my mind which is a worse experience for consumers of the libraries for these types. Claiming that Java supports these types but throwing an exception when the Vectors exceed 32-bits or just say they aren't supported until we have 64-bit support in Java. >>> >>> The vector indexes being limited to 32 bits doesn't limit the addressing >>> to 32 bit chunks of memory. For example, you're prime example before was >>> image data. Having 2 billion images of 1mb images would still be supported >>> without changing the index addressing. >>> >>> >>> > I've asked some others on my team their opinions on the risk here. I > think we should probably review some our more complex vector interactions > and see how the jvm's assembly changes with this kind of change. Using > microbenchmarking is good but I think we also need to see whether we're > constantly inserting additional instructions or if in most cases, this > actually doesn't impact instruction count. Is this something that your team will take on? >>> >>> >>> Yeah, we need to look at this I think. >>> >>> Do you need a rebased version of the PR or is the existing one sufficient? >>> >>> Rebase would help if possible. >>> >>> >>> Thanks, Micah On Thu, Aug 22, 2019 at 8:56 PM Jacques Nadeau wrote: > I don't think we should couple this discussion with the implementation > of large list, etc since I think those two concepts are independent. > > I've asked some others on my team their opinions on the risk here. I > think we should probably review some our more complex vector interactions > and see how the jvm's assembly changes with this kind of change. Using > microbenchmarking is good but I think we also need to see whether we're > constantly inserting additional instructions or if in most cases, this > actually doesn't impact instruction count. > > > > On Wed, Aug 21, 2019 at 12:18 PM Micah Kornfield < > emkornfi...@gmail.com> wrote: > >> >>> With regards to the reference implementation point. It is a good >>> point. I'm on vacation this week. Unless you're pushing hard on this, >>> can >>> we pick this up and discuss more next week? >> >> >> Hi Jacques, I hope you had a good rest. Any more thoughts on the >> reference implementation aspect of this? >> >> >>> To copy the sentiments from the 0.15.0 release thread, I think it >>> would be best to decouple
Re: [Discuss][Java] 64-bit lengths for ValueVectors
On Fri, Aug 23, 2019, 8:55 PM Micah Kornfield wrote: > The vector indexes being limited to 32 bits doesn't limit the addressing >> to 32 bit chunks of memory. For example, you're prime example before was >> image data. Having 2 billion images of 1mb images would still be supported >> without changing the index addressing. > > This might be pre-coffee math, but I think we are limited to approximately > 2000 images because an ArrowBuf only holds up-to 2 billion bytes [1]. > While we have plenty of room for the offsets, we quickly run out of > contiguous data storage space. For LargeString and LargeBinary this could > be fixed by changing ArrowBuf. > > LargeArray faces the same problem only it applies to its child vectors. > Supporting LargeArray properly is really what drove the large-scale > interface change. > My expressed concern about these changes was specifically about the use of long for get/set in the vector interfaces. I'm not saying that we constrain memory/ArrowBufs to 32bits. > Rebase would help if possible. > > I'll try to get to this in the next few days. > > [1] > https://github.com/apache/arrow/blob/95175fe7cb8439eebe6d2f6e0495f551d6864380/java/memory/src/main/java/io/netty/buffer/ArrowBuf.java#L164 > > On Fri, Aug 23, 2019 at 4:55 AM Jacques Nadeau wrote: > >> >> >> On Fri, Aug 23, 2019, 11:49 AM Micah Kornfield >> wrote: >> >>> I don't think we should couple this discussion with the implementation of large list, etc since I think those two concepts are independent. >>> >>> I'm still trying to balance in my mind which is a worse experience for >>> consumers of the libraries for these types. Claiming that Java supports >>> these types but throwing an exception when the Vectors exceed 32-bits or >>> just say they aren't supported until we have 64-bit support in Java. >>> >> >> The vector indexes being limited to 32 bits doesn't limit the addressing >> to 32 bit chunks of memory. For example, you're prime example before was >> image data. Having 2 billion images of 1mb images would still be supported >> without changing the index addressing. >> >> >> >>> I've asked some others on my team their opinions on the risk here. I think we should probably review some our more complex vector interactions and see how the jvm's assembly changes with this kind of change. Using microbenchmarking is good but I think we also need to see whether we're constantly inserting additional instructions or if in most cases, this actually doesn't impact instruction count. >>> >>> >>> Is this something that your team will take on? >>> >> >> >> Yeah, we need to look at this I think. >> >> Do you need a rebased version of the PR or is the existing one sufficient? >>> >> >> Rebase would help if possible. >> >> >> >>> Thanks, >>> Micah >>> >>> On Thu, Aug 22, 2019 at 8:56 PM Jacques Nadeau >>> wrote: >>> I don't think we should couple this discussion with the implementation of large list, etc since I think those two concepts are independent. I've asked some others on my team their opinions on the risk here. I think we should probably review some our more complex vector interactions and see how the jvm's assembly changes with this kind of change. Using microbenchmarking is good but I think we also need to see whether we're constantly inserting additional instructions or if in most cases, this actually doesn't impact instruction count. On Wed, Aug 21, 2019 at 12:18 PM Micah Kornfield wrote: > >> With regards to the reference implementation point. It is a good >> point. I'm on vacation this week. Unless you're pushing hard on this, can >> we pick this up and discuss more next week? > > > Hi Jacques, I hope you had a good rest. Any more thoughts on the > reference implementation aspect of this? > > >> To copy the sentiments from the 0.15.0 release thread, I think it >> would be best to decouple this discussion from the release timeline >> given how many people we have relying on regular releases coming out. >> We can keep continue making major 0.x releases until we're ready to >> release 1.0.0. > > > I'm OK with it as long as other stakeholders are. Timed releases are > the way to go. As stated on the release thread [1] we need a better > mechanism to avoid this type of issue arising again. The release thread > also had some more discussion on compatibility. > > Thanks, > Micah > > [1] > https://lists.apache.org/thread.html/d70feeceaf2570906ade117030b29887af7c77ca5c4a976e6d555920@%3Cdev.arrow.apache.org%3E > > > On Wed, Aug 14, 2019 at 3:23 PM Wes McKinney > wrote: > >> On Sun, Aug 11, 2019 at 9:40 PM Micah Kornfield < >> emkornfi...@gmail.com> wrote: >> > >> > Hi Wes and Jacques, >> > See responses below. >> > >> > With regards to the reference
Re: [Discuss][Java] 64-bit lengths for ValueVectors
> > The vector indexes being limited to 32 bits doesn't limit the addressing > to 32 bit chunks of memory. For example, you're prime example before was > image data. Having 2 billion images of 1mb images would still be supported > without changing the index addressing. This might be pre-coffee math, but I think we are limited to approximately 2000 images because an ArrowBuf only holds up-to 2 billion bytes [1]. While we have plenty of room for the offsets, we quickly run out of contiguous data storage space. For LargeString and LargeBinary this could be fixed by changing ArrowBuf. LargeArray faces the same problem only it applies to its child vectors. Supporting LargeArray properly is really what drove the large-scale interface change. Rebase would help if possible. I'll try to get to this in the next few days. [1] https://github.com/apache/arrow/blob/95175fe7cb8439eebe6d2f6e0495f551d6864380/java/memory/src/main/java/io/netty/buffer/ArrowBuf.java#L164 On Fri, Aug 23, 2019 at 4:55 AM Jacques Nadeau wrote: > > > On Fri, Aug 23, 2019, 11:49 AM Micah Kornfield > wrote: > >> I don't think we should couple this discussion with the implementation of >>> large list, etc since I think those two concepts are independent. >> >> I'm still trying to balance in my mind which is a worse experience for >> consumers of the libraries for these types. Claiming that Java supports >> these types but throwing an exception when the Vectors exceed 32-bits or >> just say they aren't supported until we have 64-bit support in Java. >> > > The vector indexes being limited to 32 bits doesn't limit the addressing > to 32 bit chunks of memory. For example, you're prime example before was > image data. Having 2 billion images of 1mb images would still be supported > without changing the index addressing. > > > >> >>> I've asked some others on my team their opinions on the risk here. I >>> think we should probably review some our more complex vector interactions >>> and see how the jvm's assembly changes with this kind of change. Using >>> microbenchmarking is good but I think we also need to see whether we're >>> constantly inserting additional instructions or if in most cases, this >>> actually doesn't impact instruction count. >> >> >> Is this something that your team will take on? >> > > > Yeah, we need to look at this I think. > > Do you need a rebased version of the PR or is the existing one sufficient? >> > > Rebase would help if possible. > > > >> Thanks, >> Micah >> >> On Thu, Aug 22, 2019 at 8:56 PM Jacques Nadeau >> wrote: >> >>> I don't think we should couple this discussion with the implementation >>> of large list, etc since I think those two concepts are independent. >>> >>> I've asked some others on my team their opinions on the risk here. I >>> think we should probably review some our more complex vector interactions >>> and see how the jvm's assembly changes with this kind of change. Using >>> microbenchmarking is good but I think we also need to see whether we're >>> constantly inserting additional instructions or if in most cases, this >>> actually doesn't impact instruction count. >>> >>> >>> >>> On Wed, Aug 21, 2019 at 12:18 PM Micah Kornfield >>> wrote: >>> > With regards to the reference implementation point. It is a good > point. I'm on vacation this week. Unless you're pushing hard on this, can > we pick this up and discuss more next week? Hi Jacques, I hope you had a good rest. Any more thoughts on the reference implementation aspect of this? > To copy the sentiments from the 0.15.0 release thread, I think it > would be best to decouple this discussion from the release timeline > given how many people we have relying on regular releases coming out. > We can keep continue making major 0.x releases until we're ready to > release 1.0.0. I'm OK with it as long as other stakeholders are. Timed releases are the way to go. As stated on the release thread [1] we need a better mechanism to avoid this type of issue arising again. The release thread also had some more discussion on compatibility. Thanks, Micah [1] https://lists.apache.org/thread.html/d70feeceaf2570906ade117030b29887af7c77ca5c4a976e6d555920@%3Cdev.arrow.apache.org%3E On Wed, Aug 14, 2019 at 3:23 PM Wes McKinney wrote: > On Sun, Aug 11, 2019 at 9:40 PM Micah Kornfield > wrote: > > > > Hi Wes and Jacques, > > See responses below. > > > > With regards to the reference implementation point. It is a good > point. I'm > > > on vacation this week. Unless you're pushing hard on this, can we > pick this > > > up and discuss more next week? > > > > > > Sure thing, enjoy your vacation. I think the only practical > implications > > are it delays choices around implementing LargeList, LargeBinary, > > LargeString in Java, which in turn
Re: [Discuss][Java] 64-bit lengths for ValueVectors
On Fri, Aug 23, 2019, 11:49 AM Micah Kornfield wrote: > I don't think we should couple this discussion with the implementation of >> large list, etc since I think those two concepts are independent. > > I'm still trying to balance in my mind which is a worse experience for > consumers of the libraries for these types. Claiming that Java supports > these types but throwing an exception when the Vectors exceed 32-bits or > just say they aren't supported until we have 64-bit support in Java. > The vector indexes being limited to 32 bits doesn't limit the addressing to 32 bit chunks of memory. For example, you're prime example before was image data. Having 2 billion images of 1mb images would still be supported without changing the index addressing. > >> I've asked some others on my team their opinions on the risk here. I >> think we should probably review some our more complex vector interactions >> and see how the jvm's assembly changes with this kind of change. Using >> microbenchmarking is good but I think we also need to see whether we're >> constantly inserting additional instructions or if in most cases, this >> actually doesn't impact instruction count. > > > Is this something that your team will take on? > Yeah, we need to look at this I think. Do you need a rebased version of the PR or is the existing one sufficient? > Rebase would help if possible. > Thanks, > Micah > > On Thu, Aug 22, 2019 at 8:56 PM Jacques Nadeau wrote: > >> I don't think we should couple this discussion with the implementation of >> large list, etc since I think those two concepts are independent. >> >> I've asked some others on my team their opinions on the risk here. I >> think we should probably review some our more complex vector interactions >> and see how the jvm's assembly changes with this kind of change. Using >> microbenchmarking is good but I think we also need to see whether we're >> constantly inserting additional instructions or if in most cases, this >> actually doesn't impact instruction count. >> >> >> >> On Wed, Aug 21, 2019 at 12:18 PM Micah Kornfield >> wrote: >> >>> With regards to the reference implementation point. It is a good point. I'm on vacation this week. Unless you're pushing hard on this, can we pick this up and discuss more next week? >>> >>> >>> Hi Jacques, I hope you had a good rest. Any more thoughts on the >>> reference implementation aspect of this? >>> >>> To copy the sentiments from the 0.15.0 release thread, I think it would be best to decouple this discussion from the release timeline given how many people we have relying on regular releases coming out. We can keep continue making major 0.x releases until we're ready to release 1.0.0. >>> >>> >>> I'm OK with it as long as other stakeholders are. Timed releases are the >>> way to go. As stated on the release thread [1] we need a better mechanism >>> to avoid this type of issue arising again. The release thread also had >>> some more discussion on compatibility. >>> >>> Thanks, >>> Micah >>> >>> [1] >>> https://lists.apache.org/thread.html/d70feeceaf2570906ade117030b29887af7c77ca5c4a976e6d555920@%3Cdev.arrow.apache.org%3E >>> >>> >>> On Wed, Aug 14, 2019 at 3:23 PM Wes McKinney >>> wrote: >>> On Sun, Aug 11, 2019 at 9:40 PM Micah Kornfield wrote: > > Hi Wes and Jacques, > See responses below. > > With regards to the reference implementation point. It is a good point. I'm > > on vacation this week. Unless you're pushing hard on this, can we pick this > > up and discuss more next week? > > > Sure thing, enjoy your vacation. I think the only practical implications > are it delays choices around implementing LargeList, LargeBinary, > LargeString in Java, which in turn might push out the 0.15.0 release. > To copy the sentiments from the 0.15.0 release thread, I think it would be best to decouple this discussion from the release timeline given how many people we have relying on regular releases coming out. We can keep continue making major 0.x releases until we're ready to release 1.0.0. > My stance on this is that I don't know how important it is for Java to > > support vectors over INT32_MAX elements. The use cases enabled by > > having very large arrays seem to be concentrated in the native code > > world (e.g. C/C++/Rust) -- that could just be implementation-centrism > > on my part, though. > > > A data point against this view is Spark has done work to eliminate 2GB > memory limits on its block sizes [1]. I don't claim to understand the > implications of this. Bryan might you have any thoughts here? I'm OK with > INT32_MAX, as well, I think we should think about what this means for > adding Large types to Java and implications for reference implementations. > > Thanks,
Re: [Discuss][Java] 64-bit lengths for ValueVectors
> > I don't think we should couple this discussion with the implementation of > large list, etc since I think those two concepts are independent. I'm still trying to balance in my mind which is a worse experience for consumers of the libraries for these types. Claiming that Java supports these types but throwing an exception when the Vectors exceed 32-bits or just say they aren't supported until we have 64-bit support in Java. > I've asked some others on my team their opinions on the risk here. I think > we should probably review some our more complex vector interactions and see > how the jvm's assembly changes with this kind of change. Using > microbenchmarking is good but I think we also need to see whether we're > constantly inserting additional instructions or if in most cases, this > actually doesn't impact instruction count. Is this something that your team will take on? Do you need a rebased version of the PR or is the existing one sufficient? Thanks, Micah On Thu, Aug 22, 2019 at 8:56 PM Jacques Nadeau wrote: > I don't think we should couple this discussion with the implementation of > large list, etc since I think those two concepts are independent. > > I've asked some others on my team their opinions on the risk here. I think > we should probably review some our more complex vector interactions and see > how the jvm's assembly changes with this kind of change. Using > microbenchmarking is good but I think we also need to see whether we're > constantly inserting additional instructions or if in most cases, this > actually doesn't impact instruction count. > > > > On Wed, Aug 21, 2019 at 12:18 PM Micah Kornfield > wrote: > >> >>> With regards to the reference implementation point. It is a good point. >>> I'm on vacation this week. Unless you're pushing hard on this, can we pick >>> this up and discuss more next week? >> >> >> Hi Jacques, I hope you had a good rest. Any more thoughts on the >> reference implementation aspect of this? >> >> >>> To copy the sentiments from the 0.15.0 release thread, I think it >>> would be best to decouple this discussion from the release timeline >>> given how many people we have relying on regular releases coming out. >>> We can keep continue making major 0.x releases until we're ready to >>> release 1.0.0. >> >> >> I'm OK with it as long as other stakeholders are. Timed releases are the >> way to go. As stated on the release thread [1] we need a better mechanism >> to avoid this type of issue arising again. The release thread also had >> some more discussion on compatibility. >> >> Thanks, >> Micah >> >> [1] >> https://lists.apache.org/thread.html/d70feeceaf2570906ade117030b29887af7c77ca5c4a976e6d555920@%3Cdev.arrow.apache.org%3E >> >> >> On Wed, Aug 14, 2019 at 3:23 PM Wes McKinney wrote: >> >>> On Sun, Aug 11, 2019 at 9:40 PM Micah Kornfield >>> wrote: >>> > >>> > Hi Wes and Jacques, >>> > See responses below. >>> > >>> > With regards to the reference implementation point. It is a good >>> point. I'm >>> > > on vacation this week. Unless you're pushing hard on this, can we >>> pick this >>> > > up and discuss more next week? >>> > >>> > >>> > Sure thing, enjoy your vacation. I think the only practical >>> implications >>> > are it delays choices around implementing LargeList, LargeBinary, >>> > LargeString in Java, which in turn might push out the 0.15.0 release. >>> > >>> >>> To copy the sentiments from the 0.15.0 release thread, I think it >>> would be best to decouple this discussion from the release timeline >>> given how many people we have relying on regular releases coming out. >>> We can keep continue making major 0.x releases until we're ready to >>> release 1.0.0. >>> >>> > My stance on this is that I don't know how important it is for Java to >>> > > support vectors over INT32_MAX elements. The use cases enabled by >>> > > having very large arrays seem to be concentrated in the native code >>> > > world (e.g. C/C++/Rust) -- that could just be implementation-centrism >>> > > on my part, though. >>> > >>> > >>> > A data point against this view is Spark has done work to eliminate 2GB >>> > memory limits on its block sizes [1]. I don't claim to understand the >>> > implications of this. Bryan might you have any thoughts here? I'm OK >>> with >>> > INT32_MAX, as well, I think we should think about what this means for >>> > adding Large types to Java and implications for reference >>> implementations. >>> > >>> > Thanks, >>> > Micah >>> > >>> > [1] https://issues.apache.org/jira/browse/SPARK-6235 >>> > >>> > On Sun, Aug 11, 2019 at 6:31 PM Jacques Nadeau >>> wrote: >>> > >>> > > Hey Micah, >>> > > >>> > > Appreciate the offer on the compiling. The reality is I'm more >>> concerned >>> > > about the unknowns than the compiling issue itself. Any time you've >>> been >>> > > tuning for a while, changing something like this could be totally >>> fine or >>> > > cause a couple of major issues. For example, we've done a very large >>> amount
Re: [Discuss][Java] 64-bit lengths for ValueVectors
I don't think we should couple this discussion with the implementation of large list, etc since I think those two concepts are independent. I've asked some others on my team their opinions on the risk here. I think we should probably review some our more complex vector interactions and see how the jvm's assembly changes with this kind of change. Using microbenchmarking is good but I think we also need to see whether we're constantly inserting additional instructions or if in most cases, this actually doesn't impact instruction count. On Wed, Aug 21, 2019 at 12:18 PM Micah Kornfield wrote: > >> With regards to the reference implementation point. It is a good point. >> I'm on vacation this week. Unless you're pushing hard on this, can we pick >> this up and discuss more next week? > > > Hi Jacques, I hope you had a good rest. Any more thoughts on the > reference implementation aspect of this? > > >> To copy the sentiments from the 0.15.0 release thread, I think it >> would be best to decouple this discussion from the release timeline >> given how many people we have relying on regular releases coming out. >> We can keep continue making major 0.x releases until we're ready to >> release 1.0.0. > > > I'm OK with it as long as other stakeholders are. Timed releases are the > way to go. As stated on the release thread [1] we need a better mechanism > to avoid this type of issue arising again. The release thread also had > some more discussion on compatibility. > > Thanks, > Micah > > [1] > https://lists.apache.org/thread.html/d70feeceaf2570906ade117030b29887af7c77ca5c4a976e6d555920@%3Cdev.arrow.apache.org%3E > > > On Wed, Aug 14, 2019 at 3:23 PM Wes McKinney wrote: > >> On Sun, Aug 11, 2019 at 9:40 PM Micah Kornfield >> wrote: >> > >> > Hi Wes and Jacques, >> > See responses below. >> > >> > With regards to the reference implementation point. It is a good point. >> I'm >> > > on vacation this week. Unless you're pushing hard on this, can we >> pick this >> > > up and discuss more next week? >> > >> > >> > Sure thing, enjoy your vacation. I think the only practical >> implications >> > are it delays choices around implementing LargeList, LargeBinary, >> > LargeString in Java, which in turn might push out the 0.15.0 release. >> > >> >> To copy the sentiments from the 0.15.0 release thread, I think it >> would be best to decouple this discussion from the release timeline >> given how many people we have relying on regular releases coming out. >> We can keep continue making major 0.x releases until we're ready to >> release 1.0.0. >> >> > My stance on this is that I don't know how important it is for Java to >> > > support vectors over INT32_MAX elements. The use cases enabled by >> > > having very large arrays seem to be concentrated in the native code >> > > world (e.g. C/C++/Rust) -- that could just be implementation-centrism >> > > on my part, though. >> > >> > >> > A data point against this view is Spark has done work to eliminate 2GB >> > memory limits on its block sizes [1]. I don't claim to understand the >> > implications of this. Bryan might you have any thoughts here? I'm OK >> with >> > INT32_MAX, as well, I think we should think about what this means for >> > adding Large types to Java and implications for reference >> implementations. >> > >> > Thanks, >> > Micah >> > >> > [1] https://issues.apache.org/jira/browse/SPARK-6235 >> > >> > On Sun, Aug 11, 2019 at 6:31 PM Jacques Nadeau >> wrote: >> > >> > > Hey Micah, >> > > >> > > Appreciate the offer on the compiling. The reality is I'm more >> concerned >> > > about the unknowns than the compiling issue itself. Any time you've >> been >> > > tuning for a while, changing something like this could be totally >> fine or >> > > cause a couple of major issues. For example, we've done a very large >> amount >> > > of work reducing heap memory footprint of the vectors. Are target is >> to >> > > actually get it down to 24 bytes per ArrowBuf and 24 bytes heap per >> vector >> > > (not including arrow bufs). >> > > >> > > With regards to the reference implementation point. It is a good >> point. >> > > I'm on vacation this week. Unless you're pushing hard on this, can we >> pick >> > > this up and discuss more next week? >> > > >> > > thanks, >> > > Jacques >> > > >> > > On Sat, Aug 10, 2019 at 7:39 PM Micah Kornfield < >> emkornfi...@gmail.com> >> > > wrote: >> > > >> > >> Hi Jacques, >> > >> I definitely understand these concerns and this change is risky >> because it >> > >> is so large. Perhaps, creating a new hierarchy, might be the >> cleanest way >> > >> of dealing with this. This could have other benefits like cleaning >> up >> > >> some >> > >> cruft around dictionary encode and "orphaned" method. Per past >> e-mail >> > >> threads I agree it is beneficial to have 2 separate reference >> > >> implementations that can communicate fully, and my intent here was to >> > >> close >> > >> that gap. >> > >> >> > >> Trying to >> > >> >
Re: [Discuss][Java] 64-bit lengths for ValueVectors
> > Hi Jacques, I hope you had a good rest. I did, thanks! On Fri, Aug 23, 2019 at 9:25 AM Jacques Nadeau wrote: > I don't think we should couple this discussion with the implementation of > large list, etc since I think those two concepts are independent. > > I've asked some others on my team their opinions on the risk here. I think > we should probably review some our more complex vector interactions and see > how the jvm's assembly changes with this kind of change. Using > microbenchmarking is good but I think we also need to see whether we're > constantly inserting additional instructions or if in most cases, this > actually doesn't impact instruction count. > > > > On Wed, Aug 21, 2019 at 12:18 PM Micah Kornfield > wrote: > >> >>> With regards to the reference implementation point. It is a good point. >>> I'm on vacation this week. Unless you're pushing hard on this, can we pick >>> this up and discuss more next week? >> >> >> Hi Jacques, I hope you had a good rest. Any more thoughts on the >> reference implementation aspect of this? >> >> >>> To copy the sentiments from the 0.15.0 release thread, I think it >>> would be best to decouple this discussion from the release timeline >>> given how many people we have relying on regular releases coming out. >>> We can keep continue making major 0.x releases until we're ready to >>> release 1.0.0. >> >> >> I'm OK with it as long as other stakeholders are. Timed releases are the >> way to go. As stated on the release thread [1] we need a better mechanism >> to avoid this type of issue arising again. The release thread also had >> some more discussion on compatibility. >> >> Thanks, >> Micah >> >> [1] >> https://lists.apache.org/thread.html/d70feeceaf2570906ade117030b29887af7c77ca5c4a976e6d555920@%3Cdev.arrow.apache.org%3E >> >> >> On Wed, Aug 14, 2019 at 3:23 PM Wes McKinney wrote: >> >>> On Sun, Aug 11, 2019 at 9:40 PM Micah Kornfield >>> wrote: >>> > >>> > Hi Wes and Jacques, >>> > See responses below. >>> > >>> > With regards to the reference implementation point. It is a good >>> point. I'm >>> > > on vacation this week. Unless you're pushing hard on this, can we >>> pick this >>> > > up and discuss more next week? >>> > >>> > >>> > Sure thing, enjoy your vacation. I think the only practical >>> implications >>> > are it delays choices around implementing LargeList, LargeBinary, >>> > LargeString in Java, which in turn might push out the 0.15.0 release. >>> > >>> >>> To copy the sentiments from the 0.15.0 release thread, I think it >>> would be best to decouple this discussion from the release timeline >>> given how many people we have relying on regular releases coming out. >>> We can keep continue making major 0.x releases until we're ready to >>> release 1.0.0. >>> >>> > My stance on this is that I don't know how important it is for Java to >>> > > support vectors over INT32_MAX elements. The use cases enabled by >>> > > having very large arrays seem to be concentrated in the native code >>> > > world (e.g. C/C++/Rust) -- that could just be implementation-centrism >>> > > on my part, though. >>> > >>> > >>> > A data point against this view is Spark has done work to eliminate 2GB >>> > memory limits on its block sizes [1]. I don't claim to understand the >>> > implications of this. Bryan might you have any thoughts here? I'm OK >>> with >>> > INT32_MAX, as well, I think we should think about what this means for >>> > adding Large types to Java and implications for reference >>> implementations. >>> > >>> > Thanks, >>> > Micah >>> > >>> > [1] https://issues.apache.org/jira/browse/SPARK-6235 >>> > >>> > On Sun, Aug 11, 2019 at 6:31 PM Jacques Nadeau >>> wrote: >>> > >>> > > Hey Micah, >>> > > >>> > > Appreciate the offer on the compiling. The reality is I'm more >>> concerned >>> > > about the unknowns than the compiling issue itself. Any time you've >>> been >>> > > tuning for a while, changing something like this could be totally >>> fine or >>> > > cause a couple of major issues. For example, we've done a very large >>> amount >>> > > of work reducing heap memory footprint of the vectors. Are target is >>> to >>> > > actually get it down to 24 bytes per ArrowBuf and 24 bytes heap per >>> vector >>> > > (not including arrow bufs). >>> > > >>> > > With regards to the reference implementation point. It is a good >>> point. >>> > > I'm on vacation this week. Unless you're pushing hard on this, can >>> we pick >>> > > this up and discuss more next week? >>> > > >>> > > thanks, >>> > > Jacques >>> > > >>> > > On Sat, Aug 10, 2019 at 7:39 PM Micah Kornfield < >>> emkornfi...@gmail.com> >>> > > wrote: >>> > > >>> > >> Hi Jacques, >>> > >> I definitely understand these concerns and this change is risky >>> because it >>> > >> is so large. Perhaps, creating a new hierarchy, might be the >>> cleanest way >>> > >> of dealing with this. This could have other benefits like cleaning >>> up >>> > >> some >>> > >> cruft around dictionary encode and
Re: [Discuss][Java] 64-bit lengths for ValueVectors
> > > With regards to the reference implementation point. It is a good point. > I'm on vacation this week. Unless you're pushing hard on this, can we pick > this up and discuss more next week? Hi Jacques, I hope you had a good rest. Any more thoughts on the reference implementation aspect of this? > To copy the sentiments from the 0.15.0 release thread, I think it > would be best to decouple this discussion from the release timeline > given how many people we have relying on regular releases coming out. > We can keep continue making major 0.x releases until we're ready to > release 1.0.0. I'm OK with it as long as other stakeholders are. Timed releases are the way to go. As stated on the release thread [1] we need a better mechanism to avoid this type of issue arising again. The release thread also had some more discussion on compatibility. Thanks, Micah [1] https://lists.apache.org/thread.html/d70feeceaf2570906ade117030b29887af7c77ca5c4a976e6d555920@%3Cdev.arrow.apache.org%3E On Wed, Aug 14, 2019 at 3:23 PM Wes McKinney wrote: > On Sun, Aug 11, 2019 at 9:40 PM Micah Kornfield > wrote: > > > > Hi Wes and Jacques, > > See responses below. > > > > With regards to the reference implementation point. It is a good point. > I'm > > > on vacation this week. Unless you're pushing hard on this, can we pick > this > > > up and discuss more next week? > > > > > > Sure thing, enjoy your vacation. I think the only practical implications > > are it delays choices around implementing LargeList, LargeBinary, > > LargeString in Java, which in turn might push out the 0.15.0 release. > > > > To copy the sentiments from the 0.15.0 release thread, I think it > would be best to decouple this discussion from the release timeline > given how many people we have relying on regular releases coming out. > We can keep continue making major 0.x releases until we're ready to > release 1.0.0. > > > My stance on this is that I don't know how important it is for Java to > > > support vectors over INT32_MAX elements. The use cases enabled by > > > having very large arrays seem to be concentrated in the native code > > > world (e.g. C/C++/Rust) -- that could just be implementation-centrism > > > on my part, though. > > > > > > A data point against this view is Spark has done work to eliminate 2GB > > memory limits on its block sizes [1]. I don't claim to understand the > > implications of this. Bryan might you have any thoughts here? I'm OK > with > > INT32_MAX, as well, I think we should think about what this means for > > adding Large types to Java and implications for reference > implementations. > > > > Thanks, > > Micah > > > > [1] https://issues.apache.org/jira/browse/SPARK-6235 > > > > On Sun, Aug 11, 2019 at 6:31 PM Jacques Nadeau > wrote: > > > > > Hey Micah, > > > > > > Appreciate the offer on the compiling. The reality is I'm more > concerned > > > about the unknowns than the compiling issue itself. Any time you've > been > > > tuning for a while, changing something like this could be totally fine > or > > > cause a couple of major issues. For example, we've done a very large > amount > > > of work reducing heap memory footprint of the vectors. Are target is to > > > actually get it down to 24 bytes per ArrowBuf and 24 bytes heap per > vector > > > (not including arrow bufs). > > > > > > With regards to the reference implementation point. It is a good point. > > > I'm on vacation this week. Unless you're pushing hard on this, can we > pick > > > this up and discuss more next week? > > > > > > thanks, > > > Jacques > > > > > > On Sat, Aug 10, 2019 at 7:39 PM Micah Kornfield > > > > wrote: > > > > > >> Hi Jacques, > > >> I definitely understand these concerns and this change is risky > because it > > >> is so large. Perhaps, creating a new hierarchy, might be the > cleanest way > > >> of dealing with this. This could have other benefits like cleaning up > > >> some > > >> cruft around dictionary encode and "orphaned" method. Per past > e-mail > > >> threads I agree it is beneficial to have 2 separate reference > > >> implementations that can communicate fully, and my intent here was to > > >> close > > >> that gap. > > >> > > >> Trying to > > >> > determine the ramifications of these changes would be challenging > and > > >> time > > >> > consuming against all the different ways we interact with the Arrow > Java > > >> > library. > > >> > > >> > > >> Understood. I took a quick look at Dremio-OSS it seems like it has a > > >> simple java build system? If it is helpful, I can try to get a fork > > >> running that at least compiles against this PR. My plan would be to > cast > > >> any place that was changed to return a long back to an int, so in > essence > > >> the Dremio algorithms would reman 32-bit implementations. > > >> > > >> I don't have the infrastructure to test this change properly from a > > >> distributed systems perspective, so it would still take some time from > > >> Dremio to validate
Re: [Discuss][Java] 64-bit lengths for ValueVectors
On Sun, Aug 11, 2019 at 9:40 PM Micah Kornfield wrote: > > Hi Wes and Jacques, > See responses below. > > With regards to the reference implementation point. It is a good point. I'm > > on vacation this week. Unless you're pushing hard on this, can we pick this > > up and discuss more next week? > > > Sure thing, enjoy your vacation. I think the only practical implications > are it delays choices around implementing LargeList, LargeBinary, > LargeString in Java, which in turn might push out the 0.15.0 release. > To copy the sentiments from the 0.15.0 release thread, I think it would be best to decouple this discussion from the release timeline given how many people we have relying on regular releases coming out. We can keep continue making major 0.x releases until we're ready to release 1.0.0. > My stance on this is that I don't know how important it is for Java to > > support vectors over INT32_MAX elements. The use cases enabled by > > having very large arrays seem to be concentrated in the native code > > world (e.g. C/C++/Rust) -- that could just be implementation-centrism > > on my part, though. > > > A data point against this view is Spark has done work to eliminate 2GB > memory limits on its block sizes [1]. I don't claim to understand the > implications of this. Bryan might you have any thoughts here? I'm OK with > INT32_MAX, as well, I think we should think about what this means for > adding Large types to Java and implications for reference implementations. > > Thanks, > Micah > > [1] https://issues.apache.org/jira/browse/SPARK-6235 > > On Sun, Aug 11, 2019 at 6:31 PM Jacques Nadeau wrote: > > > Hey Micah, > > > > Appreciate the offer on the compiling. The reality is I'm more concerned > > about the unknowns than the compiling issue itself. Any time you've been > > tuning for a while, changing something like this could be totally fine or > > cause a couple of major issues. For example, we've done a very large amount > > of work reducing heap memory footprint of the vectors. Are target is to > > actually get it down to 24 bytes per ArrowBuf and 24 bytes heap per vector > > (not including arrow bufs). > > > > With regards to the reference implementation point. It is a good point. > > I'm on vacation this week. Unless you're pushing hard on this, can we pick > > this up and discuss more next week? > > > > thanks, > > Jacques > > > > On Sat, Aug 10, 2019 at 7:39 PM Micah Kornfield > > wrote: > > > >> Hi Jacques, > >> I definitely understand these concerns and this change is risky because it > >> is so large. Perhaps, creating a new hierarchy, might be the cleanest way > >> of dealing with this. This could have other benefits like cleaning up > >> some > >> cruft around dictionary encode and "orphaned" method. Per past e-mail > >> threads I agree it is beneficial to have 2 separate reference > >> implementations that can communicate fully, and my intent here was to > >> close > >> that gap. > >> > >> Trying to > >> > determine the ramifications of these changes would be challenging and > >> time > >> > consuming against all the different ways we interact with the Arrow Java > >> > library. > >> > >> > >> Understood. I took a quick look at Dremio-OSS it seems like it has a > >> simple java build system? If it is helpful, I can try to get a fork > >> running that at least compiles against this PR. My plan would be to cast > >> any place that was changed to return a long back to an int, so in essence > >> the Dremio algorithms would reman 32-bit implementations. > >> > >> I don't have the infrastructure to test this change properly from a > >> distributed systems perspective, so it would still take some time from > >> Dremio to validate for regressions. > >> > >> I'm not saying I'm against this but want to make sure we've > >> > explored all less disruptive options before considering changing > >> something > >> > this fundamental (especially when I generally hold the view that large > >> cell > >> > counts against massive contiguous memory is an anti pattern to scalable > >> > analytical processing--purely subjective of course). > >> > >> > >> I'm open to other ideas here, as well. I don't think it is out of the > >> question to leave the Java implementation as 32-bit, but if we do, then I > >> think we should consider a different strategy for reference > >> implementations. > >> > >> Thanks, > >> Micah > >> > >> On Sat, Aug 10, 2019 at 5:09 PM Jacques Nadeau > >> wrote: > >> > >> > Hey Micah, I didn't have a particular path in mind. Was thinking more > >> along > >> > the lines of extra methods as opposed to separate classes. > >> > > >> > Arrow hasn't historically been a place where we're writing algorithms in > >> > Java so the fact that they aren't there doesn't mean they don't exist. > >> We > >> > have a large amount of code that depends on the current behavior that is > >> > deployed in hundreds of customer clusters (you can peruse our dremio > >> repo > >> > to see how
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Hi Wes and Jacques, See responses below. With regards to the reference implementation point. It is a good point. I'm > on vacation this week. Unless you're pushing hard on this, can we pick this > up and discuss more next week? Sure thing, enjoy your vacation. I think the only practical implications are it delays choices around implementing LargeList, LargeBinary, LargeString in Java, which in turn might push out the 0.15.0 release. My stance on this is that I don't know how important it is for Java to > support vectors over INT32_MAX elements. The use cases enabled by > having very large arrays seem to be concentrated in the native code > world (e.g. C/C++/Rust) -- that could just be implementation-centrism > on my part, though. A data point against this view is Spark has done work to eliminate 2GB memory limits on its block sizes [1]. I don't claim to understand the implications of this. Bryan might you have any thoughts here? I'm OK with INT32_MAX, as well, I think we should think about what this means for adding Large types to Java and implications for reference implementations. Thanks, Micah [1] https://issues.apache.org/jira/browse/SPARK-6235 On Sun, Aug 11, 2019 at 6:31 PM Jacques Nadeau wrote: > Hey Micah, > > Appreciate the offer on the compiling. The reality is I'm more concerned > about the unknowns than the compiling issue itself. Any time you've been > tuning for a while, changing something like this could be totally fine or > cause a couple of major issues. For example, we've done a very large amount > of work reducing heap memory footprint of the vectors. Are target is to > actually get it down to 24 bytes per ArrowBuf and 24 bytes heap per vector > (not including arrow bufs). > > With regards to the reference implementation point. It is a good point. > I'm on vacation this week. Unless you're pushing hard on this, can we pick > this up and discuss more next week? > > thanks, > Jacques > > On Sat, Aug 10, 2019 at 7:39 PM Micah Kornfield > wrote: > >> Hi Jacques, >> I definitely understand these concerns and this change is risky because it >> is so large. Perhaps, creating a new hierarchy, might be the cleanest way >> of dealing with this. This could have other benefits like cleaning up >> some >> cruft around dictionary encode and "orphaned" method. Per past e-mail >> threads I agree it is beneficial to have 2 separate reference >> implementations that can communicate fully, and my intent here was to >> close >> that gap. >> >> Trying to >> > determine the ramifications of these changes would be challenging and >> time >> > consuming against all the different ways we interact with the Arrow Java >> > library. >> >> >> Understood. I took a quick look at Dremio-OSS it seems like it has a >> simple java build system? If it is helpful, I can try to get a fork >> running that at least compiles against this PR. My plan would be to cast >> any place that was changed to return a long back to an int, so in essence >> the Dremio algorithms would reman 32-bit implementations. >> >> I don't have the infrastructure to test this change properly from a >> distributed systems perspective, so it would still take some time from >> Dremio to validate for regressions. >> >> I'm not saying I'm against this but want to make sure we've >> > explored all less disruptive options before considering changing >> something >> > this fundamental (especially when I generally hold the view that large >> cell >> > counts against massive contiguous memory is an anti pattern to scalable >> > analytical processing--purely subjective of course). >> >> >> I'm open to other ideas here, as well. I don't think it is out of the >> question to leave the Java implementation as 32-bit, but if we do, then I >> think we should consider a different strategy for reference >> implementations. >> >> Thanks, >> Micah >> >> On Sat, Aug 10, 2019 at 5:09 PM Jacques Nadeau >> wrote: >> >> > Hey Micah, I didn't have a particular path in mind. Was thinking more >> along >> > the lines of extra methods as opposed to separate classes. >> > >> > Arrow hasn't historically been a place where we're writing algorithms in >> > Java so the fact that they aren't there doesn't mean they don't exist. >> We >> > have a large amount of code that depends on the current behavior that is >> > deployed in hundreds of customer clusters (you can peruse our dremio >> repo >> > to see how extensively we leverage Arrow if interested). Trying to >> > determine the ramifications of these changes would be challenging and >> time >> > consuming against all the different ways we interact with the Arrow Java >> > library. I'm not saying I'm against this but want to make sure we've >> > explored all less disruptive options before considering changing >> something >> > this fundamental (especially when I generally hold the view that large >> cell >> > counts against massive contiguous memory is an anti pattern to scalable >> > analytical
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Hey Micah, Appreciate the offer on the compiling. The reality is I'm more concerned about the unknowns than the compiling issue itself. Any time you've been tuning for a while, changing something like this could be totally fine or cause a couple of major issues. For example, we've done a very large amount of work reducing heap memory footprint of the vectors. Are target is to actually get it down to 24 bytes per ArrowBuf and 24 bytes heap per vector (not including arrow bufs). With regards to the reference implementation point. It is a good point. I'm on vacation this week. Unless you're pushing hard on this, can we pick this up and discuss more next week? thanks, Jacques On Sat, Aug 10, 2019 at 7:39 PM Micah Kornfield wrote: > Hi Jacques, > I definitely understand these concerns and this change is risky because it > is so large. Perhaps, creating a new hierarchy, might be the cleanest way > of dealing with this. This could have other benefits like cleaning up some > cruft around dictionary encode and "orphaned" method. Per past e-mail > threads I agree it is beneficial to have 2 separate reference > implementations that can communicate fully, and my intent here was to close > that gap. > > Trying to > > determine the ramifications of these changes would be challenging and > time > > consuming against all the different ways we interact with the Arrow Java > > library. > > > Understood. I took a quick look at Dremio-OSS it seems like it has a > simple java build system? If it is helpful, I can try to get a fork > running that at least compiles against this PR. My plan would be to cast > any place that was changed to return a long back to an int, so in essence > the Dremio algorithms would reman 32-bit implementations. > > I don't have the infrastructure to test this change properly from a > distributed systems perspective, so it would still take some time from > Dremio to validate for regressions. > > I'm not saying I'm against this but want to make sure we've > > explored all less disruptive options before considering changing > something > > this fundamental (especially when I generally hold the view that large > cell > > counts against massive contiguous memory is an anti pattern to scalable > > analytical processing--purely subjective of course). > > > I'm open to other ideas here, as well. I don't think it is out of the > question to leave the Java implementation as 32-bit, but if we do, then I > think we should consider a different strategy for reference > implementations. > > Thanks, > Micah > > On Sat, Aug 10, 2019 at 5:09 PM Jacques Nadeau wrote: > > > Hey Micah, I didn't have a particular path in mind. Was thinking more > along > > the lines of extra methods as opposed to separate classes. > > > > Arrow hasn't historically been a place where we're writing algorithms in > > Java so the fact that they aren't there doesn't mean they don't exist. We > > have a large amount of code that depends on the current behavior that is > > deployed in hundreds of customer clusters (you can peruse our dremio repo > > to see how extensively we leverage Arrow if interested). Trying to > > determine the ramifications of these changes would be challenging and > time > > consuming against all the different ways we interact with the Arrow Java > > library. I'm not saying I'm against this but want to make sure we've > > explored all less disruptive options before considering changing > something > > this fundamental (especially when I generally hold the view that large > cell > > counts against massive contiguous memory is an anti pattern to scalable > > analytical processing--purely subjective of course). > > > > On Sat, Aug 10, 2019, 4:17 PM Micah Kornfield > > wrote: > > > > > Hi Jacques, > > > What avenue were you thinking for supporting both paths? I didn't > want > > > to pursue a different class hierarchy, because I felt like that would > > > effectively fork the code base, but that is potentially an option that > > > would allow us to have a complete reference implementation in Java that > > can > > > fully interact with C++, without major changes to this code. > > > > > > For supporting both APIs on the same classes/interfaces, I think they > > > roughly fall into three categories, changes to input parameters, > changes > > to > > > output parameters and algorithm changes. > > > > > > For inputs, changing from int to long is essentially a no-op from the > > > compiler perspective. From the limited micro-benchmarking this also > > > doesn't seem to have a performance impact. So we could keep two > versions > > > of the methods that only differ on inputs, but it is not clear what the > > > value of that would be. > > > > > > For outputs, we can't support methods "long getLength()" and "int > > > getLength()" in the same class, so we would be forced into something > like > > > "long getLength(boolean dummy)" which I think is a less desirable. > > > > > > For algorithm changes, there did not
Re: [Discuss][Java] 64-bit lengths for ValueVectors
My stance on this is that I don't know how important it is for Java to support vectors over INT32_MAX elements. The use cases enabled by having very large arrays seem to be concentrated in the native code world (e.g. C/C++/Rust) -- that could just be implementation-centrism on my part, though. It's possible there are use cases where Java would want to be able to produce very large memory regions to be exposed to native code. On Sat, Aug 10, 2019 at 7:39 PM Micah Kornfield wrote: > > Hi Jacques, > I definitely understand these concerns and this change is risky because it > is so large. Perhaps, creating a new hierarchy, might be the cleanest way > of dealing with this. This could have other benefits like cleaning up some > cruft around dictionary encode and "orphaned" method. Per past e-mail > threads I agree it is beneficial to have 2 separate reference > implementations that can communicate fully, and my intent here was to close > that gap. > > Trying to > > determine the ramifications of these changes would be challenging and time > > consuming against all the different ways we interact with the Arrow Java > > library. > > > Understood. I took a quick look at Dremio-OSS it seems like it has a > simple java build system? If it is helpful, I can try to get a fork > running that at least compiles against this PR. My plan would be to cast > any place that was changed to return a long back to an int, so in essence > the Dremio algorithms would reman 32-bit implementations. > > I don't have the infrastructure to test this change properly from a > distributed systems perspective, so it would still take some time from > Dremio to validate for regressions. > > I'm not saying I'm against this but want to make sure we've > > explored all less disruptive options before considering changing something > > this fundamental (especially when I generally hold the view that large cell > > counts against massive contiguous memory is an anti pattern to scalable > > analytical processing--purely subjective of course). > > > I'm open to other ideas here, as well. I don't think it is out of the > question to leave the Java implementation as 32-bit, but if we do, then I > think we should consider a different strategy for reference implementations. > > Thanks, > Micah > > On Sat, Aug 10, 2019 at 5:09 PM Jacques Nadeau wrote: > > > Hey Micah, I didn't have a particular path in mind. Was thinking more along > > the lines of extra methods as opposed to separate classes. > > > > Arrow hasn't historically been a place where we're writing algorithms in > > Java so the fact that they aren't there doesn't mean they don't exist. We > > have a large amount of code that depends on the current behavior that is > > deployed in hundreds of customer clusters (you can peruse our dremio repo > > to see how extensively we leverage Arrow if interested). Trying to > > determine the ramifications of these changes would be challenging and time > > consuming against all the different ways we interact with the Arrow Java > > library. I'm not saying I'm against this but want to make sure we've > > explored all less disruptive options before considering changing something > > this fundamental (especially when I generally hold the view that large cell > > counts against massive contiguous memory is an anti pattern to scalable > > analytical processing--purely subjective of course). > > > > On Sat, Aug 10, 2019, 4:17 PM Micah Kornfield > > wrote: > > > > > Hi Jacques, > > > What avenue were you thinking for supporting both paths? I didn't want > > > to pursue a different class hierarchy, because I felt like that would > > > effectively fork the code base, but that is potentially an option that > > > would allow us to have a complete reference implementation in Java that > > can > > > fully interact with C++, without major changes to this code. > > > > > > For supporting both APIs on the same classes/interfaces, I think they > > > roughly fall into three categories, changes to input parameters, changes > > to > > > output parameters and algorithm changes. > > > > > > For inputs, changing from int to long is essentially a no-op from the > > > compiler perspective. From the limited micro-benchmarking this also > > > doesn't seem to have a performance impact. So we could keep two versions > > > of the methods that only differ on inputs, but it is not clear what the > > > value of that would be. > > > > > > For outputs, we can't support methods "long getLength()" and "int > > > getLength()" in the same class, so we would be forced into something like > > > "long getLength(boolean dummy)" which I think is a less desirable. > > > > > > For algorithm changes, there did not appear to be too many places where > > we > > > actually loop over all elements (it is quite possible I missed something > > > here), the ones that I did find I was able to mitigate performance > > > penalties as noted above. Some of the current implementation will get a > > >
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Hi Jacques, I definitely understand these concerns and this change is risky because it is so large. Perhaps, creating a new hierarchy, might be the cleanest way of dealing with this. This could have other benefits like cleaning up some cruft around dictionary encode and "orphaned" method. Per past e-mail threads I agree it is beneficial to have 2 separate reference implementations that can communicate fully, and my intent here was to close that gap. Trying to > determine the ramifications of these changes would be challenging and time > consuming against all the different ways we interact with the Arrow Java > library. Understood. I took a quick look at Dremio-OSS it seems like it has a simple java build system? If it is helpful, I can try to get a fork running that at least compiles against this PR. My plan would be to cast any place that was changed to return a long back to an int, so in essence the Dremio algorithms would reman 32-bit implementations. I don't have the infrastructure to test this change properly from a distributed systems perspective, so it would still take some time from Dremio to validate for regressions. I'm not saying I'm against this but want to make sure we've > explored all less disruptive options before considering changing something > this fundamental (especially when I generally hold the view that large cell > counts against massive contiguous memory is an anti pattern to scalable > analytical processing--purely subjective of course). I'm open to other ideas here, as well. I don't think it is out of the question to leave the Java implementation as 32-bit, but if we do, then I think we should consider a different strategy for reference implementations. Thanks, Micah On Sat, Aug 10, 2019 at 5:09 PM Jacques Nadeau wrote: > Hey Micah, I didn't have a particular path in mind. Was thinking more along > the lines of extra methods as opposed to separate classes. > > Arrow hasn't historically been a place where we're writing algorithms in > Java so the fact that they aren't there doesn't mean they don't exist. We > have a large amount of code that depends on the current behavior that is > deployed in hundreds of customer clusters (you can peruse our dremio repo > to see how extensively we leverage Arrow if interested). Trying to > determine the ramifications of these changes would be challenging and time > consuming against all the different ways we interact with the Arrow Java > library. I'm not saying I'm against this but want to make sure we've > explored all less disruptive options before considering changing something > this fundamental (especially when I generally hold the view that large cell > counts against massive contiguous memory is an anti pattern to scalable > analytical processing--purely subjective of course). > > On Sat, Aug 10, 2019, 4:17 PM Micah Kornfield > wrote: > > > Hi Jacques, > > What avenue were you thinking for supporting both paths? I didn't want > > to pursue a different class hierarchy, because I felt like that would > > effectively fork the code base, but that is potentially an option that > > would allow us to have a complete reference implementation in Java that > can > > fully interact with C++, without major changes to this code. > > > > For supporting both APIs on the same classes/interfaces, I think they > > roughly fall into three categories, changes to input parameters, changes > to > > output parameters and algorithm changes. > > > > For inputs, changing from int to long is essentially a no-op from the > > compiler perspective. From the limited micro-benchmarking this also > > doesn't seem to have a performance impact. So we could keep two versions > > of the methods that only differ on inputs, but it is not clear what the > > value of that would be. > > > > For outputs, we can't support methods "long getLength()" and "int > > getLength()" in the same class, so we would be forced into something like > > "long getLength(boolean dummy)" which I think is a less desirable. > > > > For algorithm changes, there did not appear to be too many places where > we > > actually loop over all elements (it is quite possible I missed something > > here), the ones that I did find I was able to mitigate performance > > penalties as noted above. Some of the current implementation will get a > > lot slower for "large arrays", but we can likely fix those later or in > this > > PR with a nested while loop instead of 2 for loops. > > > > Thanks, > > Micah > > > > > > On Saturday, August 10, 2019, Jacques Nadeau wrote: > > > >> This is a pretty massive change to the apis. I wonder how nasty it would > >> be to just support both paths. Have you evaluated how complex that > would be? > >> > >> On Wed, Aug 7, 2019 at 11:08 PM Micah Kornfield > >> wrote: > >> > >>> After more investigation, it looks like Float8Benchmarks at least on my > >>> machine are within the range of noise. > >>> > >>> For BitVectorHelper I pushed a new commit [1], seems to
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Hey Micah, I didn't have a particular path in mind. Was thinking more along the lines of extra methods as opposed to separate classes. Arrow hasn't historically been a place where we're writing algorithms in Java so the fact that they aren't there doesn't mean they don't exist. We have a large amount of code that depends on the current behavior that is deployed in hundreds of customer clusters (you can peruse our dremio repo to see how extensively we leverage Arrow if interested). Trying to determine the ramifications of these changes would be challenging and time consuming against all the different ways we interact with the Arrow Java library. I'm not saying I'm against this but want to make sure we've explored all less disruptive options before considering changing something this fundamental (especially when I generally hold the view that large cell counts against massive contiguous memory is an anti pattern to scalable analytical processing--purely subjective of course). On Sat, Aug 10, 2019, 4:17 PM Micah Kornfield wrote: > Hi Jacques, > What avenue were you thinking for supporting both paths? I didn't want > to pursue a different class hierarchy, because I felt like that would > effectively fork the code base, but that is potentially an option that > would allow us to have a complete reference implementation in Java that can > fully interact with C++, without major changes to this code. > > For supporting both APIs on the same classes/interfaces, I think they > roughly fall into three categories, changes to input parameters, changes to > output parameters and algorithm changes. > > For inputs, changing from int to long is essentially a no-op from the > compiler perspective. From the limited micro-benchmarking this also > doesn't seem to have a performance impact. So we could keep two versions > of the methods that only differ on inputs, but it is not clear what the > value of that would be. > > For outputs, we can't support methods "long getLength()" and "int > getLength()" in the same class, so we would be forced into something like > "long getLength(boolean dummy)" which I think is a less desirable. > > For algorithm changes, there did not appear to be too many places where we > actually loop over all elements (it is quite possible I missed something > here), the ones that I did find I was able to mitigate performance > penalties as noted above. Some of the current implementation will get a > lot slower for "large arrays", but we can likely fix those later or in this > PR with a nested while loop instead of 2 for loops. > > Thanks, > Micah > > > On Saturday, August 10, 2019, Jacques Nadeau wrote: > >> This is a pretty massive change to the apis. I wonder how nasty it would >> be to just support both paths. Have you evaluated how complex that would be? >> >> On Wed, Aug 7, 2019 at 11:08 PM Micah Kornfield >> wrote: >> >>> After more investigation, it looks like Float8Benchmarks at least on my >>> machine are within the range of noise. >>> >>> For BitVectorHelper I pushed a new commit [1], seems to bring the >>> BitVectorHelper benchmarks back inline (and even with some improvement >>> for >>> getNullCountBenchmark). >>> >>> BenchmarkMode Cnt Score >>> Error >>> Units >>> BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 3.821 ± >>> 0.031 >>> ns/op >>> BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 14.884 ± >>> 0.141 >>> ns/op >>> >>> I applied the same pattern to other loops that I could find, and for any >>> "for (long" loop on the critical path, I broke it up into two loops. the >>> first loop does iteration by integer, the second finishes off for any >>> long >>> values. As a side note it seems like optimization for loops using long >>> counters at least have a semi-recent open bug for the JVM [2] >>> >>> Thanks, >>> Micah >>> >>> [1] >>> >>> https://github.com/apache/arrow/pull/5020/commits/2ea2c1ae83e3baa7b9a99a6d06276d968df41797 >>> [2] https://bugs.openjdk.java.net/browse/JDK-8223051 >>> >>> On Wed, Aug 7, 2019 at 8:11 PM Micah Kornfield >>> wrote: >>> >>> > Indeed, the BoundChecking and CheckNullForGet variables can make a big >>> > difference. I didn't initially run the benchmarks with these turned on >>> > (you can see the result from above with Float8Benchmarks). Here are >>> new >>> > numbers including with the flags enabled. It looks like using longs >>> might >>> > be a little bit slower, I'll see what I can do to mitigate this. >>> > >>> > Ravindra also volunteered to try to benchmark the changes with Dremio's >>> > code on today's sync call. >>> > >>> > New >>> > >>> > BenchmarkMode Cnt Score >>> Error >>> > Units >>> > >>> > BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 4.176 ± >>> 1.292 >>> > ns/op >>> > >>> > BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 26.102 ± >>> 0.700 >>> > ns/op >>> > >>> >
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Hi Jacques, What avenue were you thinking for supporting both paths? I didn't want to pursue a different class hierarchy, because I felt like that would effectively fork the code base, but that is potentially an option that would allow us to have a complete reference implementation in Java that can fully interact with C++, without major changes to this code. For supporting both APIs on the same classes/interfaces, I think they roughly fall into three categories, changes to input parameters, changes to output parameters and algorithm changes. For inputs, changing from int to long is essentially a no-op from the compiler perspective. From the limited micro-benchmarking this also doesn't seem to have a performance impact. So we could keep two versions of the methods that only differ on inputs, but it is not clear what the value of that would be. For outputs, we can't support methods "long getLength()" and "int getLength()" in the same class, so we would be forced into something like "long getLength(boolean dummy)" which I think is a less desirable. For algorithm changes, there did not appear to be too many places where we actually loop over all elements (it is quite possible I missed something here), the ones that I did find I was able to mitigate performance penalties as noted above. Some of the current implementation will get a lot slower for "large arrays", but we can likely fix those later or in this PR with a nested while loop instead of 2 for loops. Thanks, Micah On Saturday, August 10, 2019, Jacques Nadeau wrote: > This is a pretty massive change to the apis. I wonder how nasty it would > be to just support both paths. Have you evaluated how complex that would be? > > On Wed, Aug 7, 2019 at 11:08 PM Micah Kornfield > wrote: > >> After more investigation, it looks like Float8Benchmarks at least on my >> machine are within the range of noise. >> >> For BitVectorHelper I pushed a new commit [1], seems to bring the >> BitVectorHelper benchmarks back inline (and even with some improvement for >> getNullCountBenchmark). >> >> BenchmarkMode Cnt Score Error >> Units >> BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 3.821 ± 0.031 >> ns/op >> BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 14.884 ± 0.141 >> ns/op >> >> I applied the same pattern to other loops that I could find, and for any >> "for (long" loop on the critical path, I broke it up into two loops. the >> first loop does iteration by integer, the second finishes off for any long >> values. As a side note it seems like optimization for loops using long >> counters at least have a semi-recent open bug for the JVM [2] >> >> Thanks, >> Micah >> >> [1] >> >> https://github.com/apache/arrow/pull/5020/commits/2ea2c1ae83e3baa7b9a99a6d06276d968df41797 >> [2] https://bugs.openjdk.java.net/browse/JDK-8223051 >> >> On Wed, Aug 7, 2019 at 8:11 PM Micah Kornfield >> wrote: >> >> > Indeed, the BoundChecking and CheckNullForGet variables can make a big >> > difference. I didn't initially run the benchmarks with these turned on >> > (you can see the result from above with Float8Benchmarks). Here are new >> > numbers including with the flags enabled. It looks like using longs >> might >> > be a little bit slower, I'll see what I can do to mitigate this. >> > >> > Ravindra also volunteered to try to benchmark the changes with Dremio's >> > code on today's sync call. >> > >> > New >> > >> > BenchmarkMode Cnt Score >> Error >> > Units >> > >> > BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 4.176 ± >> 1.292 >> > ns/op >> > >> > BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 26.102 ± >> 0.700 >> > ns/op >> > >> > Float8Benchmarks.copyFromBenchmark avgt5 7.398 ± 0.084 us/op >> > >> > Float8Benchmarks.readWriteBenchmark avgt5 2.711 ± 0.057 us/op >> > >> > >> > >> > old >> > >> > BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 3.828 ± >> 0.030 >> > ns/op >> > >> > BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 20.611 ± >> 0.188 >> > ns/op >> > >> > Float8Benchmarks.copyFromBenchmark avgt5 6.597 ± 0.462 us/op >> > >> > Float8Benchmarks.readWriteBenchmark avgt5 2.615 ± 0.027 us/op >> > >> > On Wed, Aug 7, 2019 at 7:13 PM Fan Liya wrote: >> > >> >> Hi Gonzalo, >> >> >> >> Thanks for sharing the performance results. >> >> I am wondering if you have turned off the flag >> >> BoundsChecking#BOUNDS_CHECKING_ENABLED. >> >> If not, the lower throughput should be expected. >> >> >> >> Best, >> >> Liya Fan >> >> >> >> On Wed, Aug 7, 2019 at 10:23 PM Micah Kornfield > > >> >> wrote: >> >> >> >>> Hi Gonzalo, >> >>> Thank you for the feedback. I wasn't aware of the JIT implications. >> At >> >>> least on the benchmark run they don't seem to have an impact. >> >>> >> >>> If there are other benchmarks that people have that can validate if >> this >> >>> change will be
Re: [Discuss][Java] 64-bit lengths for ValueVectors
This is a pretty massive change to the apis. I wonder how nasty it would be to just support both paths. Have you evaluated how complex that would be? On Wed, Aug 7, 2019 at 11:08 PM Micah Kornfield wrote: > After more investigation, it looks like Float8Benchmarks at least on my > machine are within the range of noise. > > For BitVectorHelper I pushed a new commit [1], seems to bring the > BitVectorHelper benchmarks back inline (and even with some improvement for > getNullCountBenchmark). > > BenchmarkMode Cnt Score Error > Units > BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 3.821 ± 0.031 > ns/op > BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 14.884 ± 0.141 > ns/op > > I applied the same pattern to other loops that I could find, and for any > "for (long" loop on the critical path, I broke it up into two loops. the > first loop does iteration by integer, the second finishes off for any long > values. As a side note it seems like optimization for loops using long > counters at least have a semi-recent open bug for the JVM [2] > > Thanks, > Micah > > [1] > > https://github.com/apache/arrow/pull/5020/commits/2ea2c1ae83e3baa7b9a99a6d06276d968df41797 > [2] https://bugs.openjdk.java.net/browse/JDK-8223051 > > On Wed, Aug 7, 2019 at 8:11 PM Micah Kornfield > wrote: > > > Indeed, the BoundChecking and CheckNullForGet variables can make a big > > difference. I didn't initially run the benchmarks with these turned on > > (you can see the result from above with Float8Benchmarks). Here are new > > numbers including with the flags enabled. It looks like using longs > might > > be a little bit slower, I'll see what I can do to mitigate this. > > > > Ravindra also volunteered to try to benchmark the changes with Dremio's > > code on today's sync call. > > > > New > > > > BenchmarkMode Cnt Score > Error > > Units > > > > BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 4.176 ± > 1.292 > > ns/op > > > > BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 26.102 ± > 0.700 > > ns/op > > > > Float8Benchmarks.copyFromBenchmark avgt5 7.398 ± 0.084 us/op > > > > Float8Benchmarks.readWriteBenchmark avgt5 2.711 ± 0.057 us/op > > > > > > > > old > > > > BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 3.828 ± > 0.030 > > ns/op > > > > BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 20.611 ± > 0.188 > > ns/op > > > > Float8Benchmarks.copyFromBenchmark avgt5 6.597 ± 0.462 us/op > > > > Float8Benchmarks.readWriteBenchmark avgt5 2.615 ± 0.027 us/op > > > > On Wed, Aug 7, 2019 at 7:13 PM Fan Liya wrote: > > > >> Hi Gonzalo, > >> > >> Thanks for sharing the performance results. > >> I am wondering if you have turned off the flag > >> BoundsChecking#BOUNDS_CHECKING_ENABLED. > >> If not, the lower throughput should be expected. > >> > >> Best, > >> Liya Fan > >> > >> On Wed, Aug 7, 2019 at 10:23 PM Micah Kornfield > >> wrote: > >> > >>> Hi Gonzalo, > >>> Thank you for the feedback. I wasn't aware of the JIT implications. > At > >>> least on the benchmark run they don't seem to have an impact. > >>> > >>> If there are other benchmarks that people have that can validate if > this > >>> change will be problematic I would appreciate trying to run them with > the > >>> PR. I will try to run the ones for zeroing/popcnt tonight to see if > >>> there > >>> is a change in those. > >>> > >>> -Micah > >>> > >>> > >>> > >>> On Wednesday, August 7, 2019, Gonzalo Ortiz Jaureguizar < > >>> golthir...@gmail.com> wrote: > >>> > >>> > I would recommend to take care with this kind of changes. > >>> > > >>> > I didn't try Arrow in more than one year, but by then the performance > >>> was > >>> > quite bad in comparison with plain byte buffer access > >>> > (see http://git.net/apache-arrow-development/msg02353.html *) and > >>> > there are several optimizations that the JVM (specifically, C2) does > >>> not > >>> > apply when dealing with int instead of longs. One of the > >>> > most commons is the loop unrolling and vectorization. > >>> > > >>> > * It doesn't seem the best way to reference an old email on the list, > >>> but > >>> > it is the only result shown by Google > >>> > > >>> > El mié., 7 ago. 2019 a las 11:42, Fan Liya () > >>> > escribió: > >>> > > >>> >> Hi Micah, > >>> >> > >>> >> Thanks for your effort. The performance result looks good. > >>> >> > >>> >> As you indicated, ArrowBuf will take additional 12 bytes (4 bytes > for > >>> each > >>> >> of length, write index, and read index). > >>> >> Similar overheads also exist for vectors like BaseFixedWidthVector, > >>> >> BaseVariableWidthVector, etc. > >>> >> > >>> >> IMO, such overheads are small enough to justify the change. > >>> >> Let's check if there are other overheads. > >>> >> > >>> >> Best, > >>> >> Liya Fan > >>> >> > >>> >> On Wed, Aug 7, 2019 at 3:30 PM Micah Kornfield < >
Re: [Discuss][Java] 64-bit lengths for ValueVectors
After more investigation, it looks like Float8Benchmarks at least on my machine are within the range of noise. For BitVectorHelper I pushed a new commit [1], seems to bring the BitVectorHelper benchmarks back inline (and even with some improvement for getNullCountBenchmark). BenchmarkMode Cnt Score Error Units BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 3.821 ± 0.031 ns/op BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 14.884 ± 0.141 ns/op I applied the same pattern to other loops that I could find, and for any "for (long" loop on the critical path, I broke it up into two loops. the first loop does iteration by integer, the second finishes off for any long values. As a side note it seems like optimization for loops using long counters at least have a semi-recent open bug for the JVM [2] Thanks, Micah [1] https://github.com/apache/arrow/pull/5020/commits/2ea2c1ae83e3baa7b9a99a6d06276d968df41797 [2] https://bugs.openjdk.java.net/browse/JDK-8223051 On Wed, Aug 7, 2019 at 8:11 PM Micah Kornfield wrote: > Indeed, the BoundChecking and CheckNullForGet variables can make a big > difference. I didn't initially run the benchmarks with these turned on > (you can see the result from above with Float8Benchmarks). Here are new > numbers including with the flags enabled. It looks like using longs might > be a little bit slower, I'll see what I can do to mitigate this. > > Ravindra also volunteered to try to benchmark the changes with Dremio's > code on today's sync call. > > New > > BenchmarkMode Cnt Score Error > Units > > BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 4.176 ± 1.292 > ns/op > > BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 26.102 ± 0.700 > ns/op > > Float8Benchmarks.copyFromBenchmark avgt5 7.398 ± 0.084 us/op > > Float8Benchmarks.readWriteBenchmark avgt5 2.711 ± 0.057 us/op > > > > old > > BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 3.828 ± 0.030 > ns/op > > BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 20.611 ± 0.188 > ns/op > > Float8Benchmarks.copyFromBenchmark avgt5 6.597 ± 0.462 us/op > > Float8Benchmarks.readWriteBenchmark avgt5 2.615 ± 0.027 us/op > > On Wed, Aug 7, 2019 at 7:13 PM Fan Liya wrote: > >> Hi Gonzalo, >> >> Thanks for sharing the performance results. >> I am wondering if you have turned off the flag >> BoundsChecking#BOUNDS_CHECKING_ENABLED. >> If not, the lower throughput should be expected. >> >> Best, >> Liya Fan >> >> On Wed, Aug 7, 2019 at 10:23 PM Micah Kornfield >> wrote: >> >>> Hi Gonzalo, >>> Thank you for the feedback. I wasn't aware of the JIT implications. At >>> least on the benchmark run they don't seem to have an impact. >>> >>> If there are other benchmarks that people have that can validate if this >>> change will be problematic I would appreciate trying to run them with the >>> PR. I will try to run the ones for zeroing/popcnt tonight to see if >>> there >>> is a change in those. >>> >>> -Micah >>> >>> >>> >>> On Wednesday, August 7, 2019, Gonzalo Ortiz Jaureguizar < >>> golthir...@gmail.com> wrote: >>> >>> > I would recommend to take care with this kind of changes. >>> > >>> > I didn't try Arrow in more than one year, but by then the performance >>> was >>> > quite bad in comparison with plain byte buffer access >>> > (see http://git.net/apache-arrow-development/msg02353.html *) and >>> > there are several optimizations that the JVM (specifically, C2) does >>> not >>> > apply when dealing with int instead of longs. One of the >>> > most commons is the loop unrolling and vectorization. >>> > >>> > * It doesn't seem the best way to reference an old email on the list, >>> but >>> > it is the only result shown by Google >>> > >>> > El mié., 7 ago. 2019 a las 11:42, Fan Liya () >>> > escribió: >>> > >>> >> Hi Micah, >>> >> >>> >> Thanks for your effort. The performance result looks good. >>> >> >>> >> As you indicated, ArrowBuf will take additional 12 bytes (4 bytes for >>> each >>> >> of length, write index, and read index). >>> >> Similar overheads also exist for vectors like BaseFixedWidthVector, >>> >> BaseVariableWidthVector, etc. >>> >> >>> >> IMO, such overheads are small enough to justify the change. >>> >> Let's check if there are other overheads. >>> >> >>> >> Best, >>> >> Liya Fan >>> >> >>> >> On Wed, Aug 7, 2019 at 3:30 PM Micah Kornfield >> > >>> >> wrote: >>> >> >>> >> > Hi Liya Fan, >>> >> > Based on the Float8Benchmark there does not seem to be any >>> meaningful >>> >> > performance difference on my machine. At least for me, the >>> benchmarks >>> >> are >>> >> > not stable enough to say one is faster than the other (I've pasted >>> >> results >>> >> > below). That being said my machine isn't necessarily the most >>> reliable >>> >> for >>> >> > benchmarking. >>> >> > >>> >> > On an intuitive level, this makes sense to
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Indeed, the BoundChecking and CheckNullForGet variables can make a big difference. I didn't initially run the benchmarks with these turned on (you can see the result from above with Float8Benchmarks). Here are new numbers including with the flags enabled. It looks like using longs might be a little bit slower, I'll see what I can do to mitigate this. Ravindra also volunteered to try to benchmark the changes with Dremio's code on today's sync call. New BenchmarkMode Cnt Score Error Units BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 4.176 ± 1.292 ns/op BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 26.102 ± 0.700 ns/op Float8Benchmarks.copyFromBenchmark avgt5 7.398 ± 0.084 us/op Float8Benchmarks.readWriteBenchmark avgt5 2.711 ± 0.057 us/op old BitVectorHelperBenchmarks.allBitsNullBenchmark avgt5 3.828 ± 0.030 ns/op BitVectorHelperBenchmarks.getNullCountBenchmark avgt5 20.611 ± 0.188 ns/op Float8Benchmarks.copyFromBenchmark avgt5 6.597 ± 0.462 us/op Float8Benchmarks.readWriteBenchmark avgt5 2.615 ± 0.027 us/op On Wed, Aug 7, 2019 at 7:13 PM Fan Liya wrote: > Hi Gonzalo, > > Thanks for sharing the performance results. > I am wondering if you have turned off the flag > BoundsChecking#BOUNDS_CHECKING_ENABLED. > If not, the lower throughput should be expected. > > Best, > Liya Fan > > On Wed, Aug 7, 2019 at 10:23 PM Micah Kornfield > wrote: > >> Hi Gonzalo, >> Thank you for the feedback. I wasn't aware of the JIT implications. At >> least on the benchmark run they don't seem to have an impact. >> >> If there are other benchmarks that people have that can validate if this >> change will be problematic I would appreciate trying to run them with the >> PR. I will try to run the ones for zeroing/popcnt tonight to see if there >> is a change in those. >> >> -Micah >> >> >> >> On Wednesday, August 7, 2019, Gonzalo Ortiz Jaureguizar < >> golthir...@gmail.com> wrote: >> >> > I would recommend to take care with this kind of changes. >> > >> > I didn't try Arrow in more than one year, but by then the performance >> was >> > quite bad in comparison with plain byte buffer access >> > (see http://git.net/apache-arrow-development/msg02353.html *) and >> > there are several optimizations that the JVM (specifically, C2) does not >> > apply when dealing with int instead of longs. One of the >> > most commons is the loop unrolling and vectorization. >> > >> > * It doesn't seem the best way to reference an old email on the list, >> but >> > it is the only result shown by Google >> > >> > El mié., 7 ago. 2019 a las 11:42, Fan Liya () >> > escribió: >> > >> >> Hi Micah, >> >> >> >> Thanks for your effort. The performance result looks good. >> >> >> >> As you indicated, ArrowBuf will take additional 12 bytes (4 bytes for >> each >> >> of length, write index, and read index). >> >> Similar overheads also exist for vectors like BaseFixedWidthVector, >> >> BaseVariableWidthVector, etc. >> >> >> >> IMO, such overheads are small enough to justify the change. >> >> Let's check if there are other overheads. >> >> >> >> Best, >> >> Liya Fan >> >> >> >> On Wed, Aug 7, 2019 at 3:30 PM Micah Kornfield >> >> wrote: >> >> >> >> > Hi Liya Fan, >> >> > Based on the Float8Benchmark there does not seem to be any meaningful >> >> > performance difference on my machine. At least for me, the >> benchmarks >> >> are >> >> > not stable enough to say one is faster than the other (I've pasted >> >> results >> >> > below). That being said my machine isn't necessarily the most >> reliable >> >> for >> >> > benchmarking. >> >> > >> >> > On an intuitive level, this makes sense to me, for the most part it >> >> seems >> >> > like the change just moves casting from "int" to "long" further up >> the >> >> > stack for "PlatformDepdendent" operations. If there are other >> >> benchmarks >> >> > that you think are worth running let me know. >> >> > >> >> > One downside performance wise I think for his change is it increases >> the >> >> > size of ArrowBuf objects, which I suppose could influence cache >> misses >> >> at >> >> > some level or increase the size of call-stacks, but this doesn't >> seem to >> >> > show up in the benchmark.. >> >> > >> >> > Thanks, >> >> > Micah >> >> > >> >> > Sample benchmark numbers: >> >> > >> >> > [New Code] >> >> > BenchmarkMode Cnt Score Error Units >> >> > Float8Benchmarks.copyFromBenchmark avgt5 15.441 ± 0.469 us/op >> >> > Float8Benchmarks.readWriteBenchmark avgt5 14.057 ± 0.115 us/op >> >> > >> >> > >> >> > [Old code] >> >> > BenchmarkMode Cnt Score Error Units >> >> > Float8Benchmarks.copyFromBenchmark avgt5 16.248 ± 1.409 us/op >> >> > Float8Benchmarks.readWriteBenchmark avgt5 14.150 ± 0.084 us/op >> >> > >> >> > On Tue, Aug 6, 2019 at 1:18 AM Fan Liya >> wrote: >> >> > >> >> >> Hi
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Hi Gonzalo, Thanks for sharing the performance results. I am wondering if you have turned off the flag BoundsChecking#BOUNDS_CHECKING_ENABLED. If not, the lower throughput should be expected. Best, Liya Fan On Wed, Aug 7, 2019 at 10:23 PM Micah Kornfield wrote: > Hi Gonzalo, > Thank you for the feedback. I wasn't aware of the JIT implications. At > least on the benchmark run they don't seem to have an impact. > > If there are other benchmarks that people have that can validate if this > change will be problematic I would appreciate trying to run them with the > PR. I will try to run the ones for zeroing/popcnt tonight to see if there > is a change in those. > > -Micah > > > > On Wednesday, August 7, 2019, Gonzalo Ortiz Jaureguizar < > golthir...@gmail.com> wrote: > > > I would recommend to take care with this kind of changes. > > > > I didn't try Arrow in more than one year, but by then the performance was > > quite bad in comparison with plain byte buffer access > > (see http://git.net/apache-arrow-development/msg02353.html *) and > > there are several optimizations that the JVM (specifically, C2) does not > > apply when dealing with int instead of longs. One of the > > most commons is the loop unrolling and vectorization. > > > > * It doesn't seem the best way to reference an old email on the list, but > > it is the only result shown by Google > > > > El mié., 7 ago. 2019 a las 11:42, Fan Liya () > > escribió: > > > >> Hi Micah, > >> > >> Thanks for your effort. The performance result looks good. > >> > >> As you indicated, ArrowBuf will take additional 12 bytes (4 bytes for > each > >> of length, write index, and read index). > >> Similar overheads also exist for vectors like BaseFixedWidthVector, > >> BaseVariableWidthVector, etc. > >> > >> IMO, such overheads are small enough to justify the change. > >> Let's check if there are other overheads. > >> > >> Best, > >> Liya Fan > >> > >> On Wed, Aug 7, 2019 at 3:30 PM Micah Kornfield > >> wrote: > >> > >> > Hi Liya Fan, > >> > Based on the Float8Benchmark there does not seem to be any meaningful > >> > performance difference on my machine. At least for me, the benchmarks > >> are > >> > not stable enough to say one is faster than the other (I've pasted > >> results > >> > below). That being said my machine isn't necessarily the most > reliable > >> for > >> > benchmarking. > >> > > >> > On an intuitive level, this makes sense to me, for the most part it > >> seems > >> > like the change just moves casting from "int" to "long" further up the > >> > stack for "PlatformDepdendent" operations. If there are other > >> benchmarks > >> > that you think are worth running let me know. > >> > > >> > One downside performance wise I think for his change is it increases > the > >> > size of ArrowBuf objects, which I suppose could influence cache misses > >> at > >> > some level or increase the size of call-stacks, but this doesn't seem > to > >> > show up in the benchmark.. > >> > > >> > Thanks, > >> > Micah > >> > > >> > Sample benchmark numbers: > >> > > >> > [New Code] > >> > BenchmarkMode Cnt Score Error Units > >> > Float8Benchmarks.copyFromBenchmark avgt5 15.441 ± 0.469 us/op > >> > Float8Benchmarks.readWriteBenchmark avgt5 14.057 ± 0.115 us/op > >> > > >> > > >> > [Old code] > >> > BenchmarkMode Cnt Score Error Units > >> > Float8Benchmarks.copyFromBenchmark avgt5 16.248 ± 1.409 us/op > >> > Float8Benchmarks.readWriteBenchmark avgt5 14.150 ± 0.084 us/op > >> > > >> > On Tue, Aug 6, 2019 at 1:18 AM Fan Liya wrote: > >> > > >> >> Hi Micah, > >> >> > >> >> Thanks a lot for doing this. > >> >> > >> >> I am a little concerned about if there is any negative performance > >> impact > >> >> on the current 32-bit-length based applications. > >> >> Can we do some performance comparison on our existing benchmarks? > >> >> > >> >> Best, > >> >> Liya Fan > >> >> > >> >> > >> >> On Tue, Aug 6, 2019 at 3:35 PM Micah Kornfield < > emkornfi...@gmail.com> > >> >> wrote: > >> >> > >> >>> There have been some previous discussions on the mailing about > >> supporting > >> >>> 64-bit lengths for Java ValueVectors (this is what the IPC > >> specification > >> >>> and C++ support). I created a PR [1] that changes all APIs that I > >> could > >> >>> find that take an index to take an "long" instead of an "int" (and > >> >>> similarly change "size/rowcount" APIs). > >> >>> > >> >>> It is a big change, so I think it is worth discussing if it is > >> something > >> >>> we > >> >>> still want to move forward with. It would be nice to come to a > >> >>> conclusion > >> >>> quickly, ideally in the next few days, to avoid a lot of merge > >> conflicts. > >> >>> > >> >>> The reason I did this work now is the C++ implementation has added > >> >>> support > >> >>> for LargeList, LargeBinary and LargeString arrays and based on prior > >> >>> discussions we need to have similar
[Discuss][Java] 64-bit lengths for ValueVectors
Hi Gonzalo, Thank you for the feedback. I wasn't aware of the JIT implications. At least on the benchmark run they don't seem to have an impact. If there are other benchmarks that people have that can validate if this change will be problematic I would appreciate trying to run them with the PR. I will try to run the ones for zeroing/popcnt tonight to see if there is a change in those. -Micah On Wednesday, August 7, 2019, Gonzalo Ortiz Jaureguizar < golthir...@gmail.com> wrote: > I would recommend to take care with this kind of changes. > > I didn't try Arrow in more than one year, but by then the performance was > quite bad in comparison with plain byte buffer access > (see http://git.net/apache-arrow-development/msg02353.html *) and > there are several optimizations that the JVM (specifically, C2) does not > apply when dealing with int instead of longs. One of the > most commons is the loop unrolling and vectorization. > > * It doesn't seem the best way to reference an old email on the list, but > it is the only result shown by Google > > El mié., 7 ago. 2019 a las 11:42, Fan Liya () > escribió: > >> Hi Micah, >> >> Thanks for your effort. The performance result looks good. >> >> As you indicated, ArrowBuf will take additional 12 bytes (4 bytes for each >> of length, write index, and read index). >> Similar overheads also exist for vectors like BaseFixedWidthVector, >> BaseVariableWidthVector, etc. >> >> IMO, such overheads are small enough to justify the change. >> Let's check if there are other overheads. >> >> Best, >> Liya Fan >> >> On Wed, Aug 7, 2019 at 3:30 PM Micah Kornfield >> wrote: >> >> > Hi Liya Fan, >> > Based on the Float8Benchmark there does not seem to be any meaningful >> > performance difference on my machine. At least for me, the benchmarks >> are >> > not stable enough to say one is faster than the other (I've pasted >> results >> > below). That being said my machine isn't necessarily the most reliable >> for >> > benchmarking. >> > >> > On an intuitive level, this makes sense to me, for the most part it >> seems >> > like the change just moves casting from "int" to "long" further up the >> > stack for "PlatformDepdendent" operations. If there are other >> benchmarks >> > that you think are worth running let me know. >> > >> > One downside performance wise I think for his change is it increases the >> > size of ArrowBuf objects, which I suppose could influence cache misses >> at >> > some level or increase the size of call-stacks, but this doesn't seem to >> > show up in the benchmark.. >> > >> > Thanks, >> > Micah >> > >> > Sample benchmark numbers: >> > >> > [New Code] >> > BenchmarkMode Cnt Score Error Units >> > Float8Benchmarks.copyFromBenchmark avgt5 15.441 ± 0.469 us/op >> > Float8Benchmarks.readWriteBenchmark avgt5 14.057 ± 0.115 us/op >> > >> > >> > [Old code] >> > BenchmarkMode Cnt Score Error Units >> > Float8Benchmarks.copyFromBenchmark avgt5 16.248 ± 1.409 us/op >> > Float8Benchmarks.readWriteBenchmark avgt5 14.150 ± 0.084 us/op >> > >> > On Tue, Aug 6, 2019 at 1:18 AM Fan Liya wrote: >> > >> >> Hi Micah, >> >> >> >> Thanks a lot for doing this. >> >> >> >> I am a little concerned about if there is any negative performance >> impact >> >> on the current 32-bit-length based applications. >> >> Can we do some performance comparison on our existing benchmarks? >> >> >> >> Best, >> >> Liya Fan >> >> >> >> >> >> On Tue, Aug 6, 2019 at 3:35 PM Micah Kornfield >> >> wrote: >> >> >> >>> There have been some previous discussions on the mailing about >> supporting >> >>> 64-bit lengths for Java ValueVectors (this is what the IPC >> specification >> >>> and C++ support). I created a PR [1] that changes all APIs that I >> could >> >>> find that take an index to take an "long" instead of an "int" (and >> >>> similarly change "size/rowcount" APIs). >> >>> >> >>> It is a big change, so I think it is worth discussing if it is >> something >> >>> we >> >>> still want to move forward with. It would be nice to come to a >> >>> conclusion >> >>> quickly, ideally in the next few days, to avoid a lot of merge >> conflicts. >> >>> >> >>> The reason I did this work now is the C++ implementation has added >> >>> support >> >>> for LargeList, LargeBinary and LargeString arrays and based on prior >> >>> discussions we need to have similar support in Java before our next >> >>> release. Support 64-bit indexes means we can have full compatibility >> and >> >>> make the most use of the types in Java. >> >>> >> >>> Look forward to hearing feedback. >> >>> >> >>> Thanks, >> >>> Micah >> >>> >> >>> [1] https://github.com/apache/arrow/pull/5020 >> >>> >> >> >> >
Re: [Discuss][Java] 64-bit lengths for ValueVectors
I would recommend to take care with this kind of changes. I didn't try Arrow in more than one year, but by then the performance was quite bad in comparison with plain byte buffer access (see http://git.net/apache-arrow-development/msg02353.html *) and there are several optimizations that the JVM (specifically, C2) does not apply when dealing with int instead of longs. One of the most commons is the loop unrolling and vectorization. * It doesn't seem the best way to reference an old email on the list, but it is the only result shown by Google El mié., 7 ago. 2019 a las 11:42, Fan Liya () escribió: > Hi Micah, > > Thanks for your effort. The performance result looks good. > > As you indicated, ArrowBuf will take additional 12 bytes (4 bytes for each > of length, write index, and read index). > Similar overheads also exist for vectors like BaseFixedWidthVector, > BaseVariableWidthVector, etc. > > IMO, such overheads are small enough to justify the change. > Let's check if there are other overheads. > > Best, > Liya Fan > > On Wed, Aug 7, 2019 at 3:30 PM Micah Kornfield > wrote: > > > Hi Liya Fan, > > Based on the Float8Benchmark there does not seem to be any meaningful > > performance difference on my machine. At least for me, the benchmarks > are > > not stable enough to say one is faster than the other (I've pasted > results > > below). That being said my machine isn't necessarily the most reliable > for > > benchmarking. > > > > On an intuitive level, this makes sense to me, for the most part it > seems > > like the change just moves casting from "int" to "long" further up the > > stack for "PlatformDepdendent" operations. If there are other > benchmarks > > that you think are worth running let me know. > > > > One downside performance wise I think for his change is it increases the > > size of ArrowBuf objects, which I suppose could influence cache misses at > > some level or increase the size of call-stacks, but this doesn't seem to > > show up in the benchmark.. > > > > Thanks, > > Micah > > > > Sample benchmark numbers: > > > > [New Code] > > BenchmarkMode Cnt Score Error Units > > Float8Benchmarks.copyFromBenchmark avgt5 15.441 ± 0.469 us/op > > Float8Benchmarks.readWriteBenchmark avgt5 14.057 ± 0.115 us/op > > > > > > [Old code] > > BenchmarkMode Cnt Score Error Units > > Float8Benchmarks.copyFromBenchmark avgt5 16.248 ± 1.409 us/op > > Float8Benchmarks.readWriteBenchmark avgt5 14.150 ± 0.084 us/op > > > > On Tue, Aug 6, 2019 at 1:18 AM Fan Liya wrote: > > > >> Hi Micah, > >> > >> Thanks a lot for doing this. > >> > >> I am a little concerned about if there is any negative performance > impact > >> on the current 32-bit-length based applications. > >> Can we do some performance comparison on our existing benchmarks? > >> > >> Best, > >> Liya Fan > >> > >> > >> On Tue, Aug 6, 2019 at 3:35 PM Micah Kornfield > >> wrote: > >> > >>> There have been some previous discussions on the mailing about > supporting > >>> 64-bit lengths for Java ValueVectors (this is what the IPC > specification > >>> and C++ support). I created a PR [1] that changes all APIs that I > could > >>> find that take an index to take an "long" instead of an "int" (and > >>> similarly change "size/rowcount" APIs). > >>> > >>> It is a big change, so I think it is worth discussing if it is > something > >>> we > >>> still want to move forward with. It would be nice to come to a > >>> conclusion > >>> quickly, ideally in the next few days, to avoid a lot of merge > conflicts. > >>> > >>> The reason I did this work now is the C++ implementation has added > >>> support > >>> for LargeList, LargeBinary and LargeString arrays and based on prior > >>> discussions we need to have similar support in Java before our next > >>> release. Support 64-bit indexes means we can have full compatibility > and > >>> make the most use of the types in Java. > >>> > >>> Look forward to hearing feedback. > >>> > >>> Thanks, > >>> Micah > >>> > >>> [1] https://github.com/apache/arrow/pull/5020 > >>> > >> >
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Hi Micah, Thanks for your effort. The performance result looks good. As you indicated, ArrowBuf will take additional 12 bytes (4 bytes for each of length, write index, and read index). Similar overheads also exist for vectors like BaseFixedWidthVector, BaseVariableWidthVector, etc. IMO, such overheads are small enough to justify the change. Let's check if there are other overheads. Best, Liya Fan On Wed, Aug 7, 2019 at 3:30 PM Micah Kornfield wrote: > Hi Liya Fan, > Based on the Float8Benchmark there does not seem to be any meaningful > performance difference on my machine. At least for me, the benchmarks are > not stable enough to say one is faster than the other (I've pasted results > below). That being said my machine isn't necessarily the most reliable for > benchmarking. > > On an intuitive level, this makes sense to me, for the most part it seems > like the change just moves casting from "int" to "long" further up the > stack for "PlatformDepdendent" operations. If there are other benchmarks > that you think are worth running let me know. > > One downside performance wise I think for his change is it increases the > size of ArrowBuf objects, which I suppose could influence cache misses at > some level or increase the size of call-stacks, but this doesn't seem to > show up in the benchmark.. > > Thanks, > Micah > > Sample benchmark numbers: > > [New Code] > BenchmarkMode Cnt Score Error Units > Float8Benchmarks.copyFromBenchmark avgt5 15.441 ± 0.469 us/op > Float8Benchmarks.readWriteBenchmark avgt5 14.057 ± 0.115 us/op > > > [Old code] > BenchmarkMode Cnt Score Error Units > Float8Benchmarks.copyFromBenchmark avgt5 16.248 ± 1.409 us/op > Float8Benchmarks.readWriteBenchmark avgt5 14.150 ± 0.084 us/op > > On Tue, Aug 6, 2019 at 1:18 AM Fan Liya wrote: > >> Hi Micah, >> >> Thanks a lot for doing this. >> >> I am a little concerned about if there is any negative performance impact >> on the current 32-bit-length based applications. >> Can we do some performance comparison on our existing benchmarks? >> >> Best, >> Liya Fan >> >> >> On Tue, Aug 6, 2019 at 3:35 PM Micah Kornfield >> wrote: >> >>> There have been some previous discussions on the mailing about supporting >>> 64-bit lengths for Java ValueVectors (this is what the IPC specification >>> and C++ support). I created a PR [1] that changes all APIs that I could >>> find that take an index to take an "long" instead of an "int" (and >>> similarly change "size/rowcount" APIs). >>> >>> It is a big change, so I think it is worth discussing if it is something >>> we >>> still want to move forward with. It would be nice to come to a >>> conclusion >>> quickly, ideally in the next few days, to avoid a lot of merge conflicts. >>> >>> The reason I did this work now is the C++ implementation has added >>> support >>> for LargeList, LargeBinary and LargeString arrays and based on prior >>> discussions we need to have similar support in Java before our next >>> release. Support 64-bit indexes means we can have full compatibility and >>> make the most use of the types in Java. >>> >>> Look forward to hearing feedback. >>> >>> Thanks, >>> Micah >>> >>> [1] https://github.com/apache/arrow/pull/5020 >>> >>
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Hi Liya Fan, Based on the Float8Benchmark there does not seem to be any meaningful performance difference on my machine. At least for me, the benchmarks are not stable enough to say one is faster than the other (I've pasted results below). That being said my machine isn't necessarily the most reliable for benchmarking. On an intuitive level, this makes sense to me, for the most part it seems like the change just moves casting from "int" to "long" further up the stack for "PlatformDepdendent" operations. If there are other benchmarks that you think are worth running let me know. One downside performance wise I think for his change is it increases the size of ArrowBuf objects, which I suppose could influence cache misses at some level or increase the size of call-stacks, but this doesn't seem to show up in the benchmark.. Thanks, Micah Sample benchmark numbers: [New Code] BenchmarkMode Cnt Score Error Units Float8Benchmarks.copyFromBenchmark avgt5 15.441 ± 0.469 us/op Float8Benchmarks.readWriteBenchmark avgt5 14.057 ± 0.115 us/op [Old code] BenchmarkMode Cnt Score Error Units Float8Benchmarks.copyFromBenchmark avgt5 16.248 ± 1.409 us/op Float8Benchmarks.readWriteBenchmark avgt5 14.150 ± 0.084 us/op On Tue, Aug 6, 2019 at 1:18 AM Fan Liya wrote: > Hi Micah, > > Thanks a lot for doing this. > > I am a little concerned about if there is any negative performance impact > on the current 32-bit-length based applications. > Can we do some performance comparison on our existing benchmarks? > > Best, > Liya Fan > > > On Tue, Aug 6, 2019 at 3:35 PM Micah Kornfield > wrote: > >> There have been some previous discussions on the mailing about supporting >> 64-bit lengths for Java ValueVectors (this is what the IPC specification >> and C++ support). I created a PR [1] that changes all APIs that I could >> find that take an index to take an "long" instead of an "int" (and >> similarly change "size/rowcount" APIs). >> >> It is a big change, so I think it is worth discussing if it is something >> we >> still want to move forward with. It would be nice to come to a conclusion >> quickly, ideally in the next few days, to avoid a lot of merge conflicts. >> >> The reason I did this work now is the C++ implementation has added support >> for LargeList, LargeBinary and LargeString arrays and based on prior >> discussions we need to have similar support in Java before our next >> release. Support 64-bit indexes means we can have full compatibility and >> make the most use of the types in Java. >> >> Look forward to hearing feedback. >> >> Thanks, >> Micah >> >> [1] https://github.com/apache/arrow/pull/5020 >> >
Re: [Discuss][Java] 64-bit lengths for ValueVectors
Hi Micah, Thanks a lot for doing this. I am a little concerned about if there is any negative performance impact on the current 32-bit-length based applications. Can we do some performance comparison on our existing benchmarks? Best, Liya Fan On Tue, Aug 6, 2019 at 3:35 PM Micah Kornfield wrote: > There have been some previous discussions on the mailing about supporting > 64-bit lengths for Java ValueVectors (this is what the IPC specification > and C++ support). I created a PR [1] that changes all APIs that I could > find that take an index to take an "long" instead of an "int" (and > similarly change "size/rowcount" APIs). > > It is a big change, so I think it is worth discussing if it is something we > still want to move forward with. It would be nice to come to a conclusion > quickly, ideally in the next few days, to avoid a lot of merge conflicts. > > The reason I did this work now is the C++ implementation has added support > for LargeList, LargeBinary and LargeString arrays and based on prior > discussions we need to have similar support in Java before our next > release. Support 64-bit indexes means we can have full compatibility and > make the most use of the types in Java. > > Look forward to hearing feedback. > > Thanks, > Micah > > [1] https://github.com/apache/arrow/pull/5020 >
[Discuss][Java] 64-bit lengths for ValueVectors
There have been some previous discussions on the mailing about supporting 64-bit lengths for Java ValueVectors (this is what the IPC specification and C++ support). I created a PR [1] that changes all APIs that I could find that take an index to take an "long" instead of an "int" (and similarly change "size/rowcount" APIs). It is a big change, so I think it is worth discussing if it is something we still want to move forward with. It would be nice to come to a conclusion quickly, ideally in the next few days, to avoid a lot of merge conflicts. The reason I did this work now is the C++ implementation has added support for LargeList, LargeBinary and LargeString arrays and based on prior discussions we need to have similar support in Java before our next release. Support 64-bit indexes means we can have full compatibility and make the most use of the types in Java. Look forward to hearing feedback. Thanks, Micah [1] https://github.com/apache/arrow/pull/5020
