Re: [Result] [VOTE] Merge HDFS-12943 branch to trunk - Consistent Reads from Standby
Agree, it isn't productive this way. I can't seem to find it, but was there a DISCUSS thread for this branch-merge? I usually recommend addressing issues on a DISCUSS thread instead of fighting things over a VOTE. +Vinod > On Dec 13, 2018, at 10:09 AM, Konstantin Shvachko > wrote: > > This vote failed due to Daryn Sharp's veto. > The concern is being addressed by HDFS-13873. I will start a new vote once > this is committed. > > Note for Daryn. Your non-responsive handling of the veto makes a bad > precedence and is a bad example of communication on the lists from a > respected member of this community. Please check your availability for > followup discussions if you choose to get involved with important decisions. > > On Fri, Dec 7, 2018 at 4:10 PM Konstantin Shvachko > wrote: > >> Hi Daryn, >> >> Wanted to backup Chen's earlier response to your concerns about rotating >> calls in the call queue. >> Our design >> 1. targets directly the livelock problem by rejecting calls on the >> Observer that are not likely to be responded in timely matter: HDFS-13873. >> 2. The call queue rotation is only done on Observers, and never on the >> active NN, so it stays free of attacks like you suggest. >> >> If this is a satisfactory mitigation for the problem could you please >> reconsider your -1, so that people could continue voting on this thread. >> >> Thanks, >> --Konst >> >> On Thu, Dec 6, 2018 at 10:38 AM Daryn Sharp wrote: >> >>> -1 pending additional info. After a cursory scan, I have serious >>> concerns regarding the design. This seems like a feature that should have >>> been purely implemented in hdfs w/o touching the common IPC layer. >>> >>> The biggest issue in the alignment context. It's purpose appears to be >>> for allowing handlers to reinsert calls back into the call queue. That's >>> completely unacceptable. A buggy or malicious client can easily cause >>> livelock in the IPC layer with handlers only looping on calls that never >>> satisfy the condition. Why is this not implemented via RetriableExceptions? >>> >>> On Thu, Dec 6, 2018 at 1:24 AM Yongjun Zhang >>> wrote: >>> Great work guys. Wonder if we can elaborate what's impact of not having #2 fixed, and why #2 is not needed for the feature to complete? 2. Need to fix automatic failover with ZKFC. Currently it does not doesn't know about ObserverNodes trying to convert them to SBNs. Thanks. --Yongjun On Wed, Dec 5, 2018 at 5:27 PM Konstantin Shvachko wrote: > Hi Hadoop developers, > > I would like to propose to merge to trunk the feature branch HDFS-12943 for > Consistent Reads from Standby Node. The feature is intended to scale read > RPC workloads. On large clusters reads comprise 95% of all RPCs to the > NameNode. We should be able to accommodate higher overall RPC workloads (up > to 4x by some estimates) by adding multiple ObserverNodes. > > The main functionality has been implemented see sub-tasks of HDFS-12943. > We followed up with the test plan. Testing was done on two independent > clusters (see HDFS-14058 and HDFS-14059) with security enabled. > We ran standard HDFS commands, MR jobs, admin commands including manual > failover. > We know of one cluster running this feature in production. > > There are a few outstanding issues: > 1. Need to provide proper documentation - a user guide for the new feature > 2. Need to fix automatic failover with ZKFC. Currently it does not doesn't > know about ObserverNodes trying to convert them to SBNs. > 3. Scale testing and performance fine-tuning > 4. As testing progresses, we continue fixing non-critical bugs like > HDFS-14116. > > I attached a unified patch to the umbrella jira for the review and Jenkins > build. > Please vote on this thread. The vote will run for 7 days until Wed Dec 12. > > Thanks, > --Konstantin > >>> >>> >>> -- >>> >>> Daryn >>> >> - To unsubscribe, e-mail: yarn-dev-unsubscr...@hadoop.apache.org For additional commands, e-mail: yarn-dev-h...@hadoop.apache.org
Re: [VOTE] Merge HDFS-12943 branch to trunk - Consistent Reads from Standby
Hi Yongjun, Good suggestion. This is essentially what HDFS-13873 is implementing to mitigate the concern. Thanks, --Konstantin On Wed, Dec 12, 2018 at 10:35 PM Yongjun Zhang wrote: > Hi Konstantin, > > Thanks for addressing my other question about failover. > > Some thought to share about the suggestion Daryn made. Seems we could try > this: let ObserverNode throws an RetriableException back to client saying > it has not reached the transaction ID to serve the client yet, maybe even > include the transaction ID gap information in the exception, then when the > client received the RetriableException, it can decide whether the continue > to send the request to the observer node again, or to the active NN when > the gap is too big. > > Though saving another RPC would help the performance with the current > implementation, I expect the above mentioned exception only happens > infrequently, so the performance won't be too bad, plus the client has a > chance to try ANN when knowing that the observer is too behind at extreme > case. > > I wonder how different the performance is between these two approaches in > cluster with real workload. > > Comments? > > --Yongjun > > On Fri, Dec 7, 2018 at 4:10 PM Konstantin Shvachko > wrote: > >> Hi Daryn, >> >> Wanted to backup Chen's earlier response to your concerns about rotating >> calls in the call queue. >> Our design >> 1. targets directly the livelock problem by rejecting calls on the >> Observer >> that are not likely to be responded in timely matter: HDFS-13873. >> 2. The call queue rotation is only done on Observers, and never on the >> active NN, so it stays free of attacks like you suggest. >> >> If this is a satisfactory mitigation for the problem could you please >> reconsider your -1, so that people could continue voting on this thread. >> >> Thanks, >> --Konst >> >> On Thu, Dec 6, 2018 at 10:38 AM Daryn Sharp wrote: >> >> > -1 pending additional info. After a cursory scan, I have serious >> concerns >> > regarding the design. This seems like a feature that should have been >> > purely implemented in hdfs w/o touching the common IPC layer. >> > >> > The biggest issue in the alignment context. It's purpose appears to be >> > for allowing handlers to reinsert calls back into the call queue. >> That's >> > completely unacceptable. A buggy or malicious client can easily cause >> > livelock in the IPC layer with handlers only looping on calls that never >> > satisfy the condition. Why is this not implemented via >> RetriableExceptions? >> > >> > On Thu, Dec 6, 2018 at 1:24 AM Yongjun Zhang >> >> > wrote: >> > >> >> Great work guys. >> >> >> >> Wonder if we can elaborate what's impact of not having #2 fixed, and >> why >> >> #2 >> >> is not needed for the feature to complete? >> >> 2. Need to fix automatic failover with ZKFC. Currently it does not >> doesn't >> >> know about ObserverNodes trying to convert them to SBNs. >> >> >> >> Thanks. >> >> --Yongjun >> >> >> >> >> >> On Wed, Dec 5, 2018 at 5:27 PM Konstantin Shvachko < >> shv.had...@gmail.com> >> >> wrote: >> >> >> >> > Hi Hadoop developers, >> >> > >> >> > I would like to propose to merge to trunk the feature branch >> HDFS-12943 >> >> for >> >> > Consistent Reads from Standby Node. The feature is intended to scale >> >> read >> >> > RPC workloads. On large clusters reads comprise 95% of all RPCs to >> the >> >> > NameNode. We should be able to accommodate higher overall RPC >> workloads >> >> (up >> >> > to 4x by some estimates) by adding multiple ObserverNodes. >> >> > >> >> > The main functionality has been implemented see sub-tasks of >> HDFS-12943. >> >> > We followed up with the test plan. Testing was done on two >> independent >> >> > clusters (see HDFS-14058 and HDFS-14059) with security enabled. >> >> > We ran standard HDFS commands, MR jobs, admin commands including >> manual >> >> > failover. >> >> > We know of one cluster running this feature in production. >> >> > >> >> > There are a few outstanding issues: >> >> > 1. Need to provide proper documentation - a user guide for the new >> >> feature >> >> > 2. Need to fix automatic failover with ZKFC. Currently it does not >> >> doesn't >> >> > know about ObserverNodes trying to convert them to SBNs. >> >> > 3. Scale testing and performance fine-tuning >> >> > 4. As testing progresses, we continue fixing non-critical bugs like >> >> > HDFS-14116. >> >> > >> >> > I attached a unified patch to the umbrella jira for the review and >> >> Jenkins >> >> > build. >> >> > Please vote on this thread. The vote will run for 7 days until Wed >> Dec >> >> 12. >> >> > >> >> > Thanks, >> >> > --Konstantin >> >> > >> >> >> > >> > >> > -- >> > >> > Daryn >> > >> >
[Result] [VOTE] Merge HDFS-12943 branch to trunk - Consistent Reads from Standby
This vote failed due to Daryn Sharp's veto. The concern is being addressed by HDFS-13873. I will start a new vote once this is committed. Note for Daryn. Your non-responsive handling of the veto makes a bad precedence and is a bad example of communication on the lists from a respected member of this community. Please check your availability for followup discussions if you choose to get involved with important decisions. On Fri, Dec 7, 2018 at 4:10 PM Konstantin Shvachko wrote: > Hi Daryn, > > Wanted to backup Chen's earlier response to your concerns about rotating > calls in the call queue. > Our design > 1. targets directly the livelock problem by rejecting calls on the > Observer that are not likely to be responded in timely matter: HDFS-13873. > 2. The call queue rotation is only done on Observers, and never on the > active NN, so it stays free of attacks like you suggest. > > If this is a satisfactory mitigation for the problem could you please > reconsider your -1, so that people could continue voting on this thread. > > Thanks, > --Konst > > On Thu, Dec 6, 2018 at 10:38 AM Daryn Sharp wrote: > >> -1 pending additional info. After a cursory scan, I have serious >> concerns regarding the design. This seems like a feature that should have >> been purely implemented in hdfs w/o touching the common IPC layer. >> >> The biggest issue in the alignment context. It's purpose appears to be >> for allowing handlers to reinsert calls back into the call queue. That's >> completely unacceptable. A buggy or malicious client can easily cause >> livelock in the IPC layer with handlers only looping on calls that never >> satisfy the condition. Why is this not implemented via RetriableExceptions? >> >> On Thu, Dec 6, 2018 at 1:24 AM Yongjun Zhang >> wrote: >> >>> Great work guys. >>> >>> Wonder if we can elaborate what's impact of not having #2 fixed, and why >>> #2 >>> is not needed for the feature to complete? >>> 2. Need to fix automatic failover with ZKFC. Currently it does not >>> doesn't >>> know about ObserverNodes trying to convert them to SBNs. >>> >>> Thanks. >>> --Yongjun >>> >>> >>> On Wed, Dec 5, 2018 at 5:27 PM Konstantin Shvachko >> > >>> wrote: >>> >>> > Hi Hadoop developers, >>> > >>> > I would like to propose to merge to trunk the feature branch >>> HDFS-12943 for >>> > Consistent Reads from Standby Node. The feature is intended to scale >>> read >>> > RPC workloads. On large clusters reads comprise 95% of all RPCs to the >>> > NameNode. We should be able to accommodate higher overall RPC >>> workloads (up >>> > to 4x by some estimates) by adding multiple ObserverNodes. >>> > >>> > The main functionality has been implemented see sub-tasks of >>> HDFS-12943. >>> > We followed up with the test plan. Testing was done on two independent >>> > clusters (see HDFS-14058 and HDFS-14059) with security enabled. >>> > We ran standard HDFS commands, MR jobs, admin commands including manual >>> > failover. >>> > We know of one cluster running this feature in production. >>> > >>> > There are a few outstanding issues: >>> > 1. Need to provide proper documentation - a user guide for the new >>> feature >>> > 2. Need to fix automatic failover with ZKFC. Currently it does not >>> doesn't >>> > know about ObserverNodes trying to convert them to SBNs. >>> > 3. Scale testing and performance fine-tuning >>> > 4. As testing progresses, we continue fixing non-critical bugs like >>> > HDFS-14116. >>> > >>> > I attached a unified patch to the umbrella jira for the review and >>> Jenkins >>> > build. >>> > Please vote on this thread. The vote will run for 7 days until Wed Dec >>> 12. >>> > >>> > Thanks, >>> > --Konstantin >>> > >>> >> >> >> -- >> >> Daryn >> >
Re: [VOTE] Merge HDFS-12943 branch to trunk - Consistent Reads from Standby
Hi Konstantin, Thanks for addressing my other question about failover. Some thought to share about the suggestion Daryn made. Seems we could try this: let ObserverNode throws an RetriableException back to client saying it has not reached the transaction ID to serve the client yet, maybe even include the transaction ID gap information in the exception, then when the client received the RetriableException, it can decide whether the continue to send the request to the observer node again, or to the active NN when the gap is too big. Though saving another RPC would help the performance with the current implementation, I expect the above mentioned exception only happens infrequently, so the performance won't be too bad, plus the client has a chance to try ANN when knowing that the observer is too behind at extreme case. I wonder how different the performance is between these two approaches in cluster with real workload. Comments? --Yongjun On Fri, Dec 7, 2018 at 4:10 PM Konstantin Shvachko wrote: > Hi Daryn, > > Wanted to backup Chen's earlier response to your concerns about rotating > calls in the call queue. > Our design > 1. targets directly the livelock problem by rejecting calls on the Observer > that are not likely to be responded in timely matter: HDFS-13873. > 2. The call queue rotation is only done on Observers, and never on the > active NN, so it stays free of attacks like you suggest. > > If this is a satisfactory mitigation for the problem could you please > reconsider your -1, so that people could continue voting on this thread. > > Thanks, > --Konst > > On Thu, Dec 6, 2018 at 10:38 AM Daryn Sharp wrote: > > > -1 pending additional info. After a cursory scan, I have serious > concerns > > regarding the design. This seems like a feature that should have been > > purely implemented in hdfs w/o touching the common IPC layer. > > > > The biggest issue in the alignment context. It's purpose appears to be > > for allowing handlers to reinsert calls back into the call queue. That's > > completely unacceptable. A buggy or malicious client can easily cause > > livelock in the IPC layer with handlers only looping on calls that never > > satisfy the condition. Why is this not implemented via > RetriableExceptions? > > > > On Thu, Dec 6, 2018 at 1:24 AM Yongjun Zhang > > > wrote: > > > >> Great work guys. > >> > >> Wonder if we can elaborate what's impact of not having #2 fixed, and why > >> #2 > >> is not needed for the feature to complete? > >> 2. Need to fix automatic failover with ZKFC. Currently it does not > doesn't > >> know about ObserverNodes trying to convert them to SBNs. > >> > >> Thanks. > >> --Yongjun > >> > >> > >> On Wed, Dec 5, 2018 at 5:27 PM Konstantin Shvachko < > shv.had...@gmail.com> > >> wrote: > >> > >> > Hi Hadoop developers, > >> > > >> > I would like to propose to merge to trunk the feature branch > HDFS-12943 > >> for > >> > Consistent Reads from Standby Node. The feature is intended to scale > >> read > >> > RPC workloads. On large clusters reads comprise 95% of all RPCs to the > >> > NameNode. We should be able to accommodate higher overall RPC > workloads > >> (up > >> > to 4x by some estimates) by adding multiple ObserverNodes. > >> > > >> > The main functionality has been implemented see sub-tasks of > HDFS-12943. > >> > We followed up with the test plan. Testing was done on two independent > >> > clusters (see HDFS-14058 and HDFS-14059) with security enabled. > >> > We ran standard HDFS commands, MR jobs, admin commands including > manual > >> > failover. > >> > We know of one cluster running this feature in production. > >> > > >> > There are a few outstanding issues: > >> > 1. Need to provide proper documentation - a user guide for the new > >> feature > >> > 2. Need to fix automatic failover with ZKFC. Currently it does not > >> doesn't > >> > know about ObserverNodes trying to convert them to SBNs. > >> > 3. Scale testing and performance fine-tuning > >> > 4. As testing progresses, we continue fixing non-critical bugs like > >> > HDFS-14116. > >> > > >> > I attached a unified patch to the umbrella jira for the review and > >> Jenkins > >> > build. > >> > Please vote on this thread. The vote will run for 7 days until Wed Dec > >> 12. > >> > > >> > Thanks, > >> > --Konstantin > >> > > >> > > > > > > -- > > > > Daryn > > >
Re: [VOTE] Merge HDFS-12943 branch to trunk - Consistent Reads from Standby
Hi Daryn, Wanted to backup Chen's earlier response to your concerns about rotating calls in the call queue. Our design 1. targets directly the livelock problem by rejecting calls on the Observer that are not likely to be responded in timely matter: HDFS-13873. 2. The call queue rotation is only done on Observers, and never on the active NN, so it stays free of attacks like you suggest. If this is a satisfactory mitigation for the problem could you please reconsider your -1, so that people could continue voting on this thread. Thanks, --Konst On Thu, Dec 6, 2018 at 10:38 AM Daryn Sharp wrote: > -1 pending additional info. After a cursory scan, I have serious concerns > regarding the design. This seems like a feature that should have been > purely implemented in hdfs w/o touching the common IPC layer. > > The biggest issue in the alignment context. It's purpose appears to be > for allowing handlers to reinsert calls back into the call queue. That's > completely unacceptable. A buggy or malicious client can easily cause > livelock in the IPC layer with handlers only looping on calls that never > satisfy the condition. Why is this not implemented via RetriableExceptions? > > On Thu, Dec 6, 2018 at 1:24 AM Yongjun Zhang > wrote: > >> Great work guys. >> >> Wonder if we can elaborate what's impact of not having #2 fixed, and why >> #2 >> is not needed for the feature to complete? >> 2. Need to fix automatic failover with ZKFC. Currently it does not doesn't >> know about ObserverNodes trying to convert them to SBNs. >> >> Thanks. >> --Yongjun >> >> >> On Wed, Dec 5, 2018 at 5:27 PM Konstantin Shvachko >> wrote: >> >> > Hi Hadoop developers, >> > >> > I would like to propose to merge to trunk the feature branch HDFS-12943 >> for >> > Consistent Reads from Standby Node. The feature is intended to scale >> read >> > RPC workloads. On large clusters reads comprise 95% of all RPCs to the >> > NameNode. We should be able to accommodate higher overall RPC workloads >> (up >> > to 4x by some estimates) by adding multiple ObserverNodes. >> > >> > The main functionality has been implemented see sub-tasks of HDFS-12943. >> > We followed up with the test plan. Testing was done on two independent >> > clusters (see HDFS-14058 and HDFS-14059) with security enabled. >> > We ran standard HDFS commands, MR jobs, admin commands including manual >> > failover. >> > We know of one cluster running this feature in production. >> > >> > There are a few outstanding issues: >> > 1. Need to provide proper documentation - a user guide for the new >> feature >> > 2. Need to fix automatic failover with ZKFC. Currently it does not >> doesn't >> > know about ObserverNodes trying to convert them to SBNs. >> > 3. Scale testing and performance fine-tuning >> > 4. As testing progresses, we continue fixing non-critical bugs like >> > HDFS-14116. >> > >> > I attached a unified patch to the umbrella jira for the review and >> Jenkins >> > build. >> > Please vote on this thread. The vote will run for 7 days until Wed Dec >> 12. >> > >> > Thanks, >> > --Konstantin >> > >> > > > -- > > Daryn >
Re: [VOTE] Merge HDFS-12943 branch to trunk - Consistent Reads from Standby
Hi Yongjun, Automatic failover sure needs to be fixed (see HDFS-14130 and HDFS-13182). Along with all other outstanding issues. We plan to continue this on trunk. The feature is usable now without this issues (see HDFS-14067). And we would like to get it in, so that people could have early access, and so that newly developed features were aware of this functionality. Let us know if you have other suggestions. Thanks, --Konstantin On Wed, Dec 5, 2018 at 11:24 PM Yongjun Zhang wrote: > Great work guys. > > Wonder if we can elaborate what's impact of not having #2 fixed, and why > #2 is not needed for the feature to complete? > 2. Need to fix automatic failover with ZKFC. Currently it does not doesn't > know about ObserverNodes trying to convert them to SBNs. > > Thanks. > --Yongjun > > > On Wed, Dec 5, 2018 at 5:27 PM Konstantin Shvachko > wrote: > >> Hi Hadoop developers, >> >> I would like to propose to merge to trunk the feature branch HDFS-12943 >> for >> Consistent Reads from Standby Node. The feature is intended to scale read >> RPC workloads. On large clusters reads comprise 95% of all RPCs to the >> NameNode. We should be able to accommodate higher overall RPC workloads >> (up >> to 4x by some estimates) by adding multiple ObserverNodes. >> >> The main functionality has been implemented see sub-tasks of HDFS-12943. >> We followed up with the test plan. Testing was done on two independent >> clusters (see HDFS-14058 and HDFS-14059) with security enabled. >> We ran standard HDFS commands, MR jobs, admin commands including manual >> failover. >> We know of one cluster running this feature in production. >> >> There are a few outstanding issues: >> 1. Need to provide proper documentation - a user guide for the new feature >> 2. Need to fix automatic failover with ZKFC. Currently it does not doesn't >> know about ObserverNodes trying to convert them to SBNs. >> 3. Scale testing and performance fine-tuning >> 4. As testing progresses, we continue fixing non-critical bugs like >> HDFS-14116. >> >> I attached a unified patch to the umbrella jira for the review and Jenkins >> build. >> Please vote on this thread. The vote will run for 7 days until Wed Dec 12. >> >> Thanks, >> --Konstantin >> >
Re: [VOTE] Merge HDFS-12943 branch to trunk - Consistent Reads from Standby
-1 pending additional info. After a cursory scan, I have serious concerns regarding the design. This seems like a feature that should have been purely implemented in hdfs w/o touching the common IPC layer. The biggest issue in the alignment context. It's purpose appears to be for allowing handlers to reinsert calls back into the call queue. That's completely unacceptable. A buggy or malicious client can easily cause livelock in the IPC layer with handlers only looping on calls that never satisfy the condition. Why is this not implemented via RetriableExceptions? On Thu, Dec 6, 2018 at 1:24 AM Yongjun Zhang wrote: > Great work guys. > > Wonder if we can elaborate what's impact of not having #2 fixed, and why #2 > is not needed for the feature to complete? > 2. Need to fix automatic failover with ZKFC. Currently it does not doesn't > know about ObserverNodes trying to convert them to SBNs. > > Thanks. > --Yongjun > > > On Wed, Dec 5, 2018 at 5:27 PM Konstantin Shvachko > wrote: > > > Hi Hadoop developers, > > > > I would like to propose to merge to trunk the feature branch HDFS-12943 > for > > Consistent Reads from Standby Node. The feature is intended to scale read > > RPC workloads. On large clusters reads comprise 95% of all RPCs to the > > NameNode. We should be able to accommodate higher overall RPC workloads > (up > > to 4x by some estimates) by adding multiple ObserverNodes. > > > > The main functionality has been implemented see sub-tasks of HDFS-12943. > > We followed up with the test plan. Testing was done on two independent > > clusters (see HDFS-14058 and HDFS-14059) with security enabled. > > We ran standard HDFS commands, MR jobs, admin commands including manual > > failover. > > We know of one cluster running this feature in production. > > > > There are a few outstanding issues: > > 1. Need to provide proper documentation - a user guide for the new > feature > > 2. Need to fix automatic failover with ZKFC. Currently it does not > doesn't > > know about ObserverNodes trying to convert them to SBNs. > > 3. Scale testing and performance fine-tuning > > 4. As testing progresses, we continue fixing non-critical bugs like > > HDFS-14116. > > > > I attached a unified patch to the umbrella jira for the review and > Jenkins > > build. > > Please vote on this thread. The vote will run for 7 days until Wed Dec > 12. > > > > Thanks, > > --Konstantin > > > -- Daryn
Re: [VOTE] Merge HDFS-12943 branch to trunk - Consistent Reads from Standby
Great work guys. Wonder if we can elaborate what's impact of not having #2 fixed, and why #2 is not needed for the feature to complete? 2. Need to fix automatic failover with ZKFC. Currently it does not doesn't know about ObserverNodes trying to convert them to SBNs. Thanks. --Yongjun On Wed, Dec 5, 2018 at 5:27 PM Konstantin Shvachko wrote: > Hi Hadoop developers, > > I would like to propose to merge to trunk the feature branch HDFS-12943 for > Consistent Reads from Standby Node. The feature is intended to scale read > RPC workloads. On large clusters reads comprise 95% of all RPCs to the > NameNode. We should be able to accommodate higher overall RPC workloads (up > to 4x by some estimates) by adding multiple ObserverNodes. > > The main functionality has been implemented see sub-tasks of HDFS-12943. > We followed up with the test plan. Testing was done on two independent > clusters (see HDFS-14058 and HDFS-14059) with security enabled. > We ran standard HDFS commands, MR jobs, admin commands including manual > failover. > We know of one cluster running this feature in production. > > There are a few outstanding issues: > 1. Need to provide proper documentation - a user guide for the new feature > 2. Need to fix automatic failover with ZKFC. Currently it does not doesn't > know about ObserverNodes trying to convert them to SBNs. > 3. Scale testing and performance fine-tuning > 4. As testing progresses, we continue fixing non-critical bugs like > HDFS-14116. > > I attached a unified patch to the umbrella jira for the review and Jenkins > build. > Please vote on this thread. The vote will run for 7 days until Wed Dec 12. > > Thanks, > --Konstantin >
Re: [VOTE] Merge HDFS-12943 branch to trunk - Consistent Reads from Standby
+1 (binding) Thanks Konstantin for leading the merge effort! I worked very closely with Chen, Konstantin, and Erik in the testing stage and I feel confident that the feature has now completed designed functionalities and has proven to be stable. Great team work with contributors from multiple companies! On Wed, Dec 5, 2018 at 5:27 PM Konstantin Shvachko wrote: > Hi Hadoop developers, > > I would like to propose to merge to trunk the feature branch HDFS-12943 for > Consistent Reads from Standby Node. The feature is intended to scale read > RPC workloads. On large clusters reads comprise 95% of all RPCs to the > NameNode. We should be able to accommodate higher overall RPC workloads (up > to 4x by some estimates) by adding multiple ObserverNodes. > > The main functionality has been implemented see sub-tasks of HDFS-12943. > We followed up with the test plan. Testing was done on two independent > clusters (see HDFS-14058 and HDFS-14059) with security enabled. > We ran standard HDFS commands, MR jobs, admin commands including manual > failover. > We know of one cluster running this feature in production. > > There are a few outstanding issues: > 1. Need to provide proper documentation - a user guide for the new feature > 2. Need to fix automatic failover with ZKFC. Currently it does not doesn't > know about ObserverNodes trying to convert them to SBNs. > 3. Scale testing and performance fine-tuning > 4. As testing progresses, we continue fixing non-critical bugs like > HDFS-14116. > > I attached a unified patch to the umbrella jira for the review and Jenkins > build. > Please vote on this thread. The vote will run for 7 days until Wed Dec 12. > > Thanks, > --Konstantin > -- Zhe Zhang Apache Hadoop Committer http://zhe-thoughts.github.io/about/ | @oldcap
[VOTE] Merge HDFS-12943 branch to trunk - Consistent Reads from Standby
Hi Hadoop developers, I would like to propose to merge to trunk the feature branch HDFS-12943 for Consistent Reads from Standby Node. The feature is intended to scale read RPC workloads. On large clusters reads comprise 95% of all RPCs to the NameNode. We should be able to accommodate higher overall RPC workloads (up to 4x by some estimates) by adding multiple ObserverNodes. The main functionality has been implemented see sub-tasks of HDFS-12943. We followed up with the test plan. Testing was done on two independent clusters (see HDFS-14058 and HDFS-14059) with security enabled. We ran standard HDFS commands, MR jobs, admin commands including manual failover. We know of one cluster running this feature in production. There are a few outstanding issues: 1. Need to provide proper documentation - a user guide for the new feature 2. Need to fix automatic failover with ZKFC. Currently it does not doesn't know about ObserverNodes trying to convert them to SBNs. 3. Scale testing and performance fine-tuning 4. As testing progresses, we continue fixing non-critical bugs like HDFS-14116. I attached a unified patch to the umbrella jira for the review and Jenkins build. Please vote on this thread. The vote will run for 7 days until Wed Dec 12. Thanks, --Konstantin
