Re: Hadoop 2 compatibility issues - tangent
With the right configuration, you could use the copy-dependencies goal of the maven-dependency-plugin to gather your dependencies to one place. -- Christopher L Tubbs II http://gravatar.com/ctubbsii On Tue, May 14, 2013 at 6:14 PM, John Vines wrote: > On that note, I was wondering if there were any suggestions for how to deal > with the laundry list of provided dependencies that Accumulo core has? > Writing packages against it is a bit ugly if not using the accumulo script > to start. Are there any maven utilities to automatically dissect provided > dependencies and make them included. > > Sent from my phone, please pardon the typos and brevity. > On May 14, 2013 6:09 PM, "Keith Turner" wrote: > >> One note about option 4. When using 1.4 users have to include hadoop core >> as a dependency in their pom. This must be done because the 1.4 Accumulo >> pom marks hadoop-core as provided. So maybe option 4 is ok if the deps in >> the profile are provided? >> >> >> On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: >> >> > So, I've run into a problem with ACCUMULO-1402 that requires a larger >> > discussion about how Accumulo 1.5.0 should support Hadoop2. >> > >> > The problem is basically that profiles should not contain >> > dependencies, because profiles don't get activated transitively. A >> > slide deck by the Maven developers point this out as a bad practice... >> > yet it's a practice we rely on for our current implementation of >> > Hadoop2 support >> > (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven >> > slide 80). >> > >> > What this means is that even if we go through the work of publishing >> > binary artifacts compiled against Hadoop2, neither our Hadoop1 >> > binaries or our Hadoop2 binaries will be able to transitively resolve >> > any dependencies defined in profiles. This has significant >> > implications to user code that depends on Accumulo Maven artifacts. >> > Every user will essentially have to explicitly add Hadoop dependencies >> > for every Accumulo artifact that has dependencies on Hadoop, either >> > because we directly or transitively depend on Hadoop (they'll have to >> > peek into the profiles in our POMs and copy/paste the profile into >> > their project). This becomes more complicated when we consider how >> > users will try to use things like Instamo. >> > >> > There are workarounds, but none of them are really pleasant. >> > >> > 1. The best way to support both major Hadoop APIs is to have separate >> > modules with separate dependencies directly in the POM. This is a fair >> > amount of work, and in my opinion, would be too disruptive for 1.5.0. >> > This solution also gets us separate binaries for separate supported >> > versions, which is useful. >> > >> > 2. A second option, and the preferred one I think for 1.5.0, is to put >> > a Hadoop2 patch in the branch's contrib directory >> > (branches/1.5/contrib) that patches the POM files to support building >> > against Hadoop2. (Acknowledgement to Keith for suggesting this >> > solution.) >> > >> > 3. A third option is to fork Accumulo, and maintain two separate >> > builds (a more traditional technique). This adds merging nightmare for >> > features/patches, but gets around some reflection hacks that we may >> > have been motivated to do in the past. I'm not a fan of this option, >> > particularly because I don't want to replicate the fork nightmare that >> > has been the history of early Hadoop itself. >> > >> > 4. The last option is to do nothing and to continue to build with the >> > separate profiles as we are, and make users discover and specify >> > transitive dependencies entirely on their own. I think this is the >> > worst option, as it essentially amounts to "ignore the problem". >> > >> > At the very least, it does not seem reasonable to complete >> > ACCUMULO-1402 for 1.5.0, given the complexity of this issue. >> > >> > Thoughts? Discussion? Vote on option? >> > >> > -- >> > Christopher L Tubbs II >> > http://gravatar.com/ctubbsii >> > >>
Re: Hadoop 2 compatibility issues - tangent
You can have maven generate a file with the classpath dependencies and also make a shaded jar. I use the classpath file for normal java processes and the shaded jar file with 'hadoop jar'. On Tue, May 14, 2013 at 6:14 PM, John Vines wrote: > On that note, I was wondering if there were any suggestions for how to deal > with the laundry list of provided dependencies that Accumulo core has? > Writing packages against it is a bit ugly if not using the accumulo script > to start. Are there any maven utilities to automatically dissect provided > dependencies and make them included. > > Sent from my phone, please pardon the typos and brevity. > On May 14, 2013 6:09 PM, "Keith Turner" wrote: > > > One note about option 4. When using 1.4 users have to include hadoop > core > > as a dependency in their pom. This must be done because the 1.4 Accumulo > > pom marks hadoop-core as provided. So maybe option 4 is ok if the deps > in > > the profile are provided? > > > > > > On Tue, May 14, 2013 at 4:40 PM, Christopher > wrote: > > > > > So, I've run into a problem with ACCUMULO-1402 that requires a larger > > > discussion about how Accumulo 1.5.0 should support Hadoop2. > > > > > > The problem is basically that profiles should not contain > > > dependencies, because profiles don't get activated transitively. A > > > slide deck by the Maven developers point this out as a bad practice... > > > yet it's a practice we rely on for our current implementation of > > > Hadoop2 support > > > (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > > > slide 80). > > > > > > What this means is that even if we go through the work of publishing > > > binary artifacts compiled against Hadoop2, neither our Hadoop1 > > > binaries or our Hadoop2 binaries will be able to transitively resolve > > > any dependencies defined in profiles. This has significant > > > implications to user code that depends on Accumulo Maven artifacts. > > > Every user will essentially have to explicitly add Hadoop dependencies > > > for every Accumulo artifact that has dependencies on Hadoop, either > > > because we directly or transitively depend on Hadoop (they'll have to > > > peek into the profiles in our POMs and copy/paste the profile into > > > their project). This becomes more complicated when we consider how > > > users will try to use things like Instamo. > > > > > > There are workarounds, but none of them are really pleasant. > > > > > > 1. The best way to support both major Hadoop APIs is to have separate > > > modules with separate dependencies directly in the POM. This is a fair > > > amount of work, and in my opinion, would be too disruptive for 1.5.0. > > > This solution also gets us separate binaries for separate supported > > > versions, which is useful. > > > > > > 2. A second option, and the preferred one I think for 1.5.0, is to put > > > a Hadoop2 patch in the branch's contrib directory > > > (branches/1.5/contrib) that patches the POM files to support building > > > against Hadoop2. (Acknowledgement to Keith for suggesting this > > > solution.) > > > > > > 3. A third option is to fork Accumulo, and maintain two separate > > > builds (a more traditional technique). This adds merging nightmare for > > > features/patches, but gets around some reflection hacks that we may > > > have been motivated to do in the past. I'm not a fan of this option, > > > particularly because I don't want to replicate the fork nightmare that > > > has been the history of early Hadoop itself. > > > > > > 4. The last option is to do nothing and to continue to build with the > > > separate profiles as we are, and make users discover and specify > > > transitive dependencies entirely on their own. I think this is the > > > worst option, as it essentially amounts to "ignore the problem". > > > > > > At the very least, it does not seem reasonable to complete > > > ACCUMULO-1402 for 1.5.0, given the complexity of this issue. > > > > > > Thoughts? Discussion? Vote on option? > > > > > > -- > > > Christopher L Tubbs II > > > http://gravatar.com/ctubbsii > > > > > >
Re: Hadoop 2 compatibility issues
I'm very much partial to the "First" option, as it's far less effort for approximately the same value (in my opinion, but in light of the enthusiasm above for hadoop2, I could be very wrong on my assessment of the value). I'm going to upload a patch to ACCUMULO-1402 soon (tiny polishing left), to demonstrate a way to push redundant jars, with an extra classifier (though I still have to build twice, to avoid maven-invoker-plugin complexity) for hadoop2-compatible binaries. If you don't mind, I'll tag you with a request to review that patch, as I'd like more details about the classifier issues you mention, in context. -- Christopher L Tubbs II http://gravatar.com/ctubbsii On Tue, May 14, 2013 at 8:27 PM, Benson Margulies wrote: > Maven will malfunction in various entertaining ways if you try to > change the GAV of the output of the build using a profile. > > Maven will malfunction in various entertaining ways if you use > classifiers on real-live-JAR files that get used as > real-live-dependencies, because it has no concept of a > pom-per-classifier. > > Where does this leave you/us? (I'm not sure that I've earned an 'us' > recently around here.) > > First, I note that 'Apache releases are source releases'. So, one > resort of scoundrels here would be to support only one hadoop in the > convenience binaries that get pushed to Maven Central, and let other > hadoop users take the source release and build for themselves. > > Second, I am reduced to suggesting an elaboration of the build in > which some tool edits poms and runs builds. The maven-invoker-plugin > could be used to run that, but a plain old script in a plain old > language might be less painful. > > I appreciate that this may not be an appealing contribution to where > things are, but it might be the best of the evil choices. > > > On Tue, May 14, 2013 at 7:50 PM, John Vines wrote: >> The compiled code is compiled code. There are no concerns of dependency >> resolution. So I see no issues in using the profile to define the gav if >> that is feasible. >> >> Sent from my phone, please pardon the typos and brevity. >> On May 14, 2013 7:47 PM, "Christopher" wrote: >> >>> Response to Benson inline, but additional note here: >>> >>> It should be noted that the situation will be made worse for the >>> solution I was considering for ACCUMULO-1402, which would move the >>> accumulo artifacts, classified by the hadoop2 variant, into the >>> profiles... meaning they will no longer resolve transitively when they >>> did before. Can go into details on that ticket, if needed. >>> >>> On Tue, May 14, 2013 at 7:41 PM, Benson Margulies >>> wrote: >>> > On Tue, May 14, 2013 at 7:36 PM, Christopher >>> wrote: >>> >> Benson- >>> >> >>> >> They produce different byte-code. That's why we're even considering >>> >> this. ACCUMULO-1402 is the ticket under which our intent is to add >>> >> classifiers, so that they can be distinguished. >>> > >>> > whoops, missed that. >>> > >>> > Then how do people succeed in just fixing up their dependencies and >>> using it? >>> >>> The specific differences are things like changes from abstract class >>> to an interface. Apparently an import of these do not produce >>> compatible byte-code, even though the method signature looks the same. >>> >>> > In any case, speaking as a Maven-maven, classifiers are absolutely, >>> > positively, a cure worse than the disease. If you want the details >>> > just ask. >>> >>> Agreed. I just don't see a good alternative here. >>> >>> >> >>> >> All- >>> >> >>> >> To Keith's point, I think perhaps all this concern is a non-issue... >>> >> because as Keith points out, the dependencies in question are marked >>> >> as "provided", and dependency resolution doesn't occur for provided >>> >> dependencies anyway... so even if we leave off the profiles, we're in >>> >> the same boat. Maybe not the boat we should be in... but certainly not >>> >> a sinking one as I had first imagined. It's as afloat as it was >>> >> before, when they were not in a profile, but still marked as >>> >> "provided". >>> >> >>> >> -- >>> >> Christopher L Tubbs II >>> >> http://gravatar.com/ctubbsii >>> >> >>> >> >>> >> On Tue, May 14, 2013 at 7:09 PM, Benson Margulies < >>> bimargul...@gmail.com> wrote: >>> >>> I just doesn't make very much sense to me to have two different GAV's >>> >>> for the very same .class files, just to get different dependencies in >>> >>> the poms. However, if someone really wanted that, I'd look to make >>> >>> some scripting that created this downstream from the main build. >>> >>> >>> >>> >>> >>> On Tue, May 14, 2013 at 6:16 PM, John Vines wrote: >>> They're the same currently. I was requesting separate gavs for hadoop >>> 2. >>> It's been on the mailing list and jira. >>> >>> Sent from my phone, please pardon the typos and brevity. >>> On May 14, 2013 6:14 PM, "Keith Turner" wrote: >>> >>> > On Tue, May 14, 2013 at 5:51 PM, Benson Margulies < >>> bimargul...@gma
Re: Hadoop 2 compatibility issues
Maven will malfunction in various entertaining ways if you try to change the GAV of the output of the build using a profile. Maven will malfunction in various entertaining ways if you use classifiers on real-live-JAR files that get used as real-live-dependencies, because it has no concept of a pom-per-classifier. Where does this leave you/us? (I'm not sure that I've earned an 'us' recently around here.) First, I note that 'Apache releases are source releases'. So, one resort of scoundrels here would be to support only one hadoop in the convenience binaries that get pushed to Maven Central, and let other hadoop users take the source release and build for themselves. Second, I am reduced to suggesting an elaboration of the build in which some tool edits poms and runs builds. The maven-invoker-plugin could be used to run that, but a plain old script in a plain old language might be less painful. I appreciate that this may not be an appealing contribution to where things are, but it might be the best of the evil choices. On Tue, May 14, 2013 at 7:50 PM, John Vines wrote: > The compiled code is compiled code. There are no concerns of dependency > resolution. So I see no issues in using the profile to define the gav if > that is feasible. > > Sent from my phone, please pardon the typos and brevity. > On May 14, 2013 7:47 PM, "Christopher" wrote: > >> Response to Benson inline, but additional note here: >> >> It should be noted that the situation will be made worse for the >> solution I was considering for ACCUMULO-1402, which would move the >> accumulo artifacts, classified by the hadoop2 variant, into the >> profiles... meaning they will no longer resolve transitively when they >> did before. Can go into details on that ticket, if needed. >> >> On Tue, May 14, 2013 at 7:41 PM, Benson Margulies >> wrote: >> > On Tue, May 14, 2013 at 7:36 PM, Christopher >> wrote: >> >> Benson- >> >> >> >> They produce different byte-code. That's why we're even considering >> >> this. ACCUMULO-1402 is the ticket under which our intent is to add >> >> classifiers, so that they can be distinguished. >> > >> > whoops, missed that. >> > >> > Then how do people succeed in just fixing up their dependencies and >> using it? >> >> The specific differences are things like changes from abstract class >> to an interface. Apparently an import of these do not produce >> compatible byte-code, even though the method signature looks the same. >> >> > In any case, speaking as a Maven-maven, classifiers are absolutely, >> > positively, a cure worse than the disease. If you want the details >> > just ask. >> >> Agreed. I just don't see a good alternative here. >> >> >> >> >> All- >> >> >> >> To Keith's point, I think perhaps all this concern is a non-issue... >> >> because as Keith points out, the dependencies in question are marked >> >> as "provided", and dependency resolution doesn't occur for provided >> >> dependencies anyway... so even if we leave off the profiles, we're in >> >> the same boat. Maybe not the boat we should be in... but certainly not >> >> a sinking one as I had first imagined. It's as afloat as it was >> >> before, when they were not in a profile, but still marked as >> >> "provided". >> >> >> >> -- >> >> Christopher L Tubbs II >> >> http://gravatar.com/ctubbsii >> >> >> >> >> >> On Tue, May 14, 2013 at 7:09 PM, Benson Margulies < >> bimargul...@gmail.com> wrote: >> >>> I just doesn't make very much sense to me to have two different GAV's >> >>> for the very same .class files, just to get different dependencies in >> >>> the poms. However, if someone really wanted that, I'd look to make >> >>> some scripting that created this downstream from the main build. >> >>> >> >>> >> >>> On Tue, May 14, 2013 at 6:16 PM, John Vines wrote: >> They're the same currently. I was requesting separate gavs for hadoop >> 2. >> It's been on the mailing list and jira. >> >> Sent from my phone, please pardon the typos and brevity. >> On May 14, 2013 6:14 PM, "Keith Turner" wrote: >> >> > On Tue, May 14, 2013 at 5:51 PM, Benson Margulies < >> bimargul...@gmail.com >> > >wrote: >> > >> > > I am a maven developer, and I'm offering this advice based on my >> > > understanding of reason why that generic advice is offered. >> > > >> > > If you have different profiles that _build different results_ but >> all >> > > deliver the same GAV, you have chaos. >> > > >> > >> > What GAV are we currently producing for hadoop 1 and hadoop 2? >> > >> > >> > > >> > > If you have different profiles that test against different >> versions of >> > > dependencies, but all deliver the same byte code at the end of the >> > > day, you don't have chaos. >> > > >> > > >> > > >> > > On Tue, May 14, 2013 at 5:48 PM, Christopher >> > wrote: >> > > > I think it's interesting that Option 4 seems to be most >> preferred... >> > > > because it'
Re: Hadoop 2 compatibility issues
The compiled code is compiled code. There are no concerns of dependency resolution. So I see no issues in using the profile to define the gav if that is feasible. Sent from my phone, please pardon the typos and brevity. On May 14, 2013 7:47 PM, "Christopher" wrote: > Response to Benson inline, but additional note here: > > It should be noted that the situation will be made worse for the > solution I was considering for ACCUMULO-1402, which would move the > accumulo artifacts, classified by the hadoop2 variant, into the > profiles... meaning they will no longer resolve transitively when they > did before. Can go into details on that ticket, if needed. > > On Tue, May 14, 2013 at 7:41 PM, Benson Margulies > wrote: > > On Tue, May 14, 2013 at 7:36 PM, Christopher > wrote: > >> Benson- > >> > >> They produce different byte-code. That's why we're even considering > >> this. ACCUMULO-1402 is the ticket under which our intent is to add > >> classifiers, so that they can be distinguished. > > > > whoops, missed that. > > > > Then how do people succeed in just fixing up their dependencies and > using it? > > The specific differences are things like changes from abstract class > to an interface. Apparently an import of these do not produce > compatible byte-code, even though the method signature looks the same. > > > In any case, speaking as a Maven-maven, classifiers are absolutely, > > positively, a cure worse than the disease. If you want the details > > just ask. > > Agreed. I just don't see a good alternative here. > > >> > >> All- > >> > >> To Keith's point, I think perhaps all this concern is a non-issue... > >> because as Keith points out, the dependencies in question are marked > >> as "provided", and dependency resolution doesn't occur for provided > >> dependencies anyway... so even if we leave off the profiles, we're in > >> the same boat. Maybe not the boat we should be in... but certainly not > >> a sinking one as I had first imagined. It's as afloat as it was > >> before, when they were not in a profile, but still marked as > >> "provided". > >> > >> -- > >> Christopher L Tubbs II > >> http://gravatar.com/ctubbsii > >> > >> > >> On Tue, May 14, 2013 at 7:09 PM, Benson Margulies < > bimargul...@gmail.com> wrote: > >>> I just doesn't make very much sense to me to have two different GAV's > >>> for the very same .class files, just to get different dependencies in > >>> the poms. However, if someone really wanted that, I'd look to make > >>> some scripting that created this downstream from the main build. > >>> > >>> > >>> On Tue, May 14, 2013 at 6:16 PM, John Vines wrote: > They're the same currently. I was requesting separate gavs for hadoop > 2. > It's been on the mailing list and jira. > > Sent from my phone, please pardon the typos and brevity. > On May 14, 2013 6:14 PM, "Keith Turner" wrote: > > > On Tue, May 14, 2013 at 5:51 PM, Benson Margulies < > bimargul...@gmail.com > > >wrote: > > > > > I am a maven developer, and I'm offering this advice based on my > > > understanding of reason why that generic advice is offered. > > > > > > If you have different profiles that _build different results_ but > all > > > deliver the same GAV, you have chaos. > > > > > > > What GAV are we currently producing for hadoop 1 and hadoop 2? > > > > > > > > > > If you have different profiles that test against different > versions of > > > dependencies, but all deliver the same byte code at the end of the > > > day, you don't have chaos. > > > > > > > > > > > > On Tue, May 14, 2013 at 5:48 PM, Christopher > > wrote: > > > > I think it's interesting that Option 4 seems to be most > preferred... > > > > because it's the *only* option that is explicitly advised > against by > > > > the Maven developers (from the information I've read). I can see > its > > > > appeal, but I really don't think that we should introduce an > explicit > > > > problem for users (that applies to users using even the Hadoop > version > > > > we directly build against... not just those using Hadoop 2... I > don't > > > > know if that point was clear), to only partially support a > version of > > > > Hadoop that is still alpha and has never had a stable release. > > > > > > > > BTW, Option 4 was how I had have achieved a solution for > > > > ACCUMULO-1402, but am reluctant to apply that patch, with this > issue > > > > outstanding, as it may exacerbate the problem. > > > > > > > > Another implication for Option 4 (the current "solution") is for > > > > 1.6.0, with the planned accumulo-maven-plugin... because it > means that > > > > the accumulo-maven-plugin will need to be configured like this: > > > > > > > > org.apache.accumulo > > > > accumulo-maven-plugin > > > > > > > >... all the required hadoop 1 dependencies to make the pl
Re: Hadoop 2 compatibility issues
Response to Benson inline, but additional note here: It should be noted that the situation will be made worse for the solution I was considering for ACCUMULO-1402, which would move the accumulo artifacts, classified by the hadoop2 variant, into the profiles... meaning they will no longer resolve transitively when they did before. Can go into details on that ticket, if needed. On Tue, May 14, 2013 at 7:41 PM, Benson Margulies wrote: > On Tue, May 14, 2013 at 7:36 PM, Christopher wrote: >> Benson- >> >> They produce different byte-code. That's why we're even considering >> this. ACCUMULO-1402 is the ticket under which our intent is to add >> classifiers, so that they can be distinguished. > > whoops, missed that. > > Then how do people succeed in just fixing up their dependencies and using it? The specific differences are things like changes from abstract class to an interface. Apparently an import of these do not produce compatible byte-code, even though the method signature looks the same. > In any case, speaking as a Maven-maven, classifiers are absolutely, > positively, a cure worse than the disease. If you want the details > just ask. Agreed. I just don't see a good alternative here. >> >> All- >> >> To Keith's point, I think perhaps all this concern is a non-issue... >> because as Keith points out, the dependencies in question are marked >> as "provided", and dependency resolution doesn't occur for provided >> dependencies anyway... so even if we leave off the profiles, we're in >> the same boat. Maybe not the boat we should be in... but certainly not >> a sinking one as I had first imagined. It's as afloat as it was >> before, when they were not in a profile, but still marked as >> "provided". >> >> -- >> Christopher L Tubbs II >> http://gravatar.com/ctubbsii >> >> >> On Tue, May 14, 2013 at 7:09 PM, Benson Margulies >> wrote: >>> I just doesn't make very much sense to me to have two different GAV's >>> for the very same .class files, just to get different dependencies in >>> the poms. However, if someone really wanted that, I'd look to make >>> some scripting that created this downstream from the main build. >>> >>> >>> On Tue, May 14, 2013 at 6:16 PM, John Vines wrote: They're the same currently. I was requesting separate gavs for hadoop 2. It's been on the mailing list and jira. Sent from my phone, please pardon the typos and brevity. On May 14, 2013 6:14 PM, "Keith Turner" wrote: > On Tue, May 14, 2013 at 5:51 PM, Benson Margulies >wrote: > > > I am a maven developer, and I'm offering this advice based on my > > understanding of reason why that generic advice is offered. > > > > If you have different profiles that _build different results_ but all > > deliver the same GAV, you have chaos. > > > > What GAV are we currently producing for hadoop 1 and hadoop 2? > > > > > > If you have different profiles that test against different versions of > > dependencies, but all deliver the same byte code at the end of the > > day, you don't have chaos. > > > > > > > > On Tue, May 14, 2013 at 5:48 PM, Christopher > wrote: > > > I think it's interesting that Option 4 seems to be most preferred... > > > because it's the *only* option that is explicitly advised against by > > > the Maven developers (from the information I've read). I can see its > > > appeal, but I really don't think that we should introduce an explicit > > > problem for users (that applies to users using even the Hadoop version > > > we directly build against... not just those using Hadoop 2... I don't > > > know if that point was clear), to only partially support a version of > > > Hadoop that is still alpha and has never had a stable release. > > > > > > BTW, Option 4 was how I had have achieved a solution for > > > ACCUMULO-1402, but am reluctant to apply that patch, with this issue > > > outstanding, as it may exacerbate the problem. > > > > > > Another implication for Option 4 (the current "solution") is for > > > 1.6.0, with the planned accumulo-maven-plugin... because it means that > > > the accumulo-maven-plugin will need to be configured like this: > > > > > > org.apache.accumulo > > > accumulo-maven-plugin > > > > > >... all the required hadoop 1 dependencies to make the plugin work, > > > even though this version only works against hadoop 1 anyway... > > > > > > ... > > > > > > > > > -- > > > Christopher L Tubbs II > > > http://gravatar.com/ctubbsii > > > > > > > > > On Tue, May 14, 2013 at 5:42 PM, Christopher > > wrote: > > >> I think Option 2 is the best solution for "waiting until we have the > > >> time to solve the problem correctly", as it ensures that transitive > > >> dependencies work for the stable version of Hadoop, and using Hadoop2
Re: Hadoop 2 compatibility issues
We've written the code such that it works in either, and then we have profiles which set the hadoop.version for convenience. The profiles also alternate between using hadoop-client and hadoop-core, but as I mentioned above, that is unnecessary. Sent from my phone, please pardon the typos and brevity. On May 14, 2013 7:42 PM, "Benson Margulies" wrote: > On Tue, May 14, 2013 at 7:36 PM, Christopher wrote: > > Benson- > > > > They produce different byte-code. That's why we're even considering > > this. ACCUMULO-1402 is the ticket under which our intent is to add > > classifiers, so that they can be distinguished. > > whoops, missed that. > > Then how do people succeed in just fixing up their dependencies and using > it? > > In any case, speaking as a Maven-maven, classifiers are absolutely, > positively, a cure worse than the disease. If you want the details > just ask. > > > > > All- > > > > To Keith's point, I think perhaps all this concern is a non-issue... > > because as Keith points out, the dependencies in question are marked > > as "provided", and dependency resolution doesn't occur for provided > > dependencies anyway... so even if we leave off the profiles, we're in > > the same boat. Maybe not the boat we should be in... but certainly not > > a sinking one as I had first imagined. It's as afloat as it was > > before, when they were not in a profile, but still marked as > > "provided". > > > > -- > > Christopher L Tubbs II > > http://gravatar.com/ctubbsii > > > > > > On Tue, May 14, 2013 at 7:09 PM, Benson Margulies > wrote: > >> I just doesn't make very much sense to me to have two different GAV's > >> for the very same .class files, just to get different dependencies in > >> the poms. However, if someone really wanted that, I'd look to make > >> some scripting that created this downstream from the main build. > >> > >> > >> On Tue, May 14, 2013 at 6:16 PM, John Vines wrote: > >>> They're the same currently. I was requesting separate gavs for hadoop > 2. > >>> It's been on the mailing list and jira. > >>> > >>> Sent from my phone, please pardon the typos and brevity. > >>> On May 14, 2013 6:14 PM, "Keith Turner" wrote: > >>> > On Tue, May 14, 2013 at 5:51 PM, Benson Margulies < > bimargul...@gmail.com > >wrote: > > > I am a maven developer, and I'm offering this advice based on my > > understanding of reason why that generic advice is offered. > > > > If you have different profiles that _build different results_ but > all > > deliver the same GAV, you have chaos. > > > > What GAV are we currently producing for hadoop 1 and hadoop 2? > > > > > > If you have different profiles that test against different versions > of > > dependencies, but all deliver the same byte code at the end of the > > day, you don't have chaos. > > > > > > > > On Tue, May 14, 2013 at 5:48 PM, Christopher > wrote: > > > I think it's interesting that Option 4 seems to be most > preferred... > > > because it's the *only* option that is explicitly advised against > by > > > the Maven developers (from the information I've read). I can see > its > > > appeal, but I really don't think that we should introduce an > explicit > > > problem for users (that applies to users using even the Hadoop > version > > > we directly build against... not just those using Hadoop 2... I > don't > > > know if that point was clear), to only partially support a > version of > > > Hadoop that is still alpha and has never had a stable release. > > > > > > BTW, Option 4 was how I had have achieved a solution for > > > ACCUMULO-1402, but am reluctant to apply that patch, with this > issue > > > outstanding, as it may exacerbate the problem. > > > > > > Another implication for Option 4 (the current "solution") is for > > > 1.6.0, with the planned accumulo-maven-plugin... because it means > that > > > the accumulo-maven-plugin will need to be configured like this: > > > > > > org.apache.accumulo > > > accumulo-maven-plugin > > > > > >... all the required hadoop 1 dependencies to make the plugin > work, > > > even though this version only works against hadoop 1 anyway... > > > > > > ... > > > > > > > > > -- > > > Christopher L Tubbs II > > > http://gravatar.com/ctubbsii > > > > > > > > > On Tue, May 14, 2013 at 5:42 PM, Christopher > > > wrote: > > >> I think Option 2 is the best solution for "waiting until we have > the > > >> time to solve the problem correctly", as it ensures that > transitive > > >> dependencies work for the stable version of Hadoop, and using > Hadoop2 > > >> is a very simple documentation issue for how to apply the patch > and > > >> rebuild. Option 4 doesn't wait... it explicitly introduces a > problem > > >> for
Re: Hadoop 2 compatibility issues
Sorry for the dupe Benson, meant to reply all Oh no Benson, the compiled code is different. The fundamental issue is that some interfaces got changes to abstract classes or vice versa. The source is the same, but class files are different. Sent from my phone, please pardon the typos and brevity. On May 14, 2013 7:09 PM, "Benson Margulies" wrote: > I just doesn't make very much sense to me to have two different GAV's > for the very same .class files, just to get different dependencies in > the poms. However, if someone really wanted that, I'd look to make > some scripting that created this downstream from the main build. > > > On Tue, May 14, 2013 at 6:16 PM, John Vines wrote: > > They're the same currently. I was requesting separate gavs for hadoop 2. > > It's been on the mailing list and jira. > > > > Sent from my phone, please pardon the typos and brevity. > > On May 14, 2013 6:14 PM, "Keith Turner" wrote: > > > >> On Tue, May 14, 2013 at 5:51 PM, Benson Margulies < > bimargul...@gmail.com > >> >wrote: > >> > >> > I am a maven developer, and I'm offering this advice based on my > >> > understanding of reason why that generic advice is offered. > >> > > >> > If you have different profiles that _build different results_ but all > >> > deliver the same GAV, you have chaos. > >> > > >> > >> What GAV are we currently producing for hadoop 1 and hadoop 2? > >> > >> > >> > > >> > If you have different profiles that test against different versions of > >> > dependencies, but all deliver the same byte code at the end of the > >> > day, you don't have chaos. > >> > > >> > > >> > > >> > On Tue, May 14, 2013 at 5:48 PM, Christopher > >> wrote: > >> > > I think it's interesting that Option 4 seems to be most preferred... > >> > > because it's the *only* option that is explicitly advised against by > >> > > the Maven developers (from the information I've read). I can see its > >> > > appeal, but I really don't think that we should introduce an > explicit > >> > > problem for users (that applies to users using even the Hadoop > version > >> > > we directly build against... not just those using Hadoop 2... I > don't > >> > > know if that point was clear), to only partially support a version > of > >> > > Hadoop that is still alpha and has never had a stable release. > >> > > > >> > > BTW, Option 4 was how I had have achieved a solution for > >> > > ACCUMULO-1402, but am reluctant to apply that patch, with this issue > >> > > outstanding, as it may exacerbate the problem. > >> > > > >> > > Another implication for Option 4 (the current "solution") is for > >> > > 1.6.0, with the planned accumulo-maven-plugin... because it means > that > >> > > the accumulo-maven-plugin will need to be configured like this: > >> > > > >> > > org.apache.accumulo > >> > > accumulo-maven-plugin > >> > > > >> > >... all the required hadoop 1 dependencies to make the plugin > work, > >> > > even though this version only works against hadoop 1 anyway... > >> > > > >> > > ... > >> > > > >> > > > >> > > -- > >> > > Christopher L Tubbs II > >> > > http://gravatar.com/ctubbsii > >> > > > >> > > > >> > > On Tue, May 14, 2013 at 5:42 PM, Christopher > >> > wrote: > >> > >> I think Option 2 is the best solution for "waiting until we have > the > >> > >> time to solve the problem correctly", as it ensures that transitive > >> > >> dependencies work for the stable version of Hadoop, and using > Hadoop2 > >> > >> is a very simple documentation issue for how to apply the patch and > >> > >> rebuild. Option 4 doesn't wait... it explicitly introduces a > problem > >> > >> for users. > >> > >> > >> > >> Option 1 is how I'm tentatively thinking about fixing it properly > in > >> > 1.6.0. > >> > >> > >> > >> > >> > >> -- > >> > >> Christopher L Tubbs II > >> > >> http://gravatar.com/ctubbsii > >> > >> > >> > >> > >> > >> On Tue, May 14, 2013 at 4:56 PM, John Vines > wrote: > >> > >>> I'm an advocate of option 4. You say that it's ignoring the > problem, > >> > >>> whereas I think it's waiting until we have the time to solve the > >> > problem > >> > >>> correctly. Your reasoning for this is for standardizing for maven > >> > >>> conventions, but the other options, while more 'correct' from a > maven > >> > >>> standpoint or a larger headache for our user base and ourselves. > In > >> > either > >> > >>> case, we're going to be breaking some sort of convention, and > while > >> > it's > >> > >>> not good, we should be doing the one that's less bad for US. The > >> > important > >> > >>> thing here, now, is that the poms work and we should go with the > >> method > >> > >>> that leaves the work minimal for our end users to utilize them. > >> > >>> > >> > >>> I do agree that 1. is the correct option in the long run. More > >> > >>> specifically, I think it boils down to having a single module > >> > compatibility > >> > >>> layer, which is how hbase deals with this issue. But like you > said, > >> we > >> > >>> don't have the time to engin
Re: Hadoop 2 compatibility issues
On Tue, May 14, 2013 at 7:36 PM, Christopher wrote: > Benson- > > They produce different byte-code. That's why we're even considering > this. ACCUMULO-1402 is the ticket under which our intent is to add > classifiers, so that they can be distinguished. whoops, missed that. Then how do people succeed in just fixing up their dependencies and using it? In any case, speaking as a Maven-maven, classifiers are absolutely, positively, a cure worse than the disease. If you want the details just ask. > > All- > > To Keith's point, I think perhaps all this concern is a non-issue... > because as Keith points out, the dependencies in question are marked > as "provided", and dependency resolution doesn't occur for provided > dependencies anyway... so even if we leave off the profiles, we're in > the same boat. Maybe not the boat we should be in... but certainly not > a sinking one as I had first imagined. It's as afloat as it was > before, when they were not in a profile, but still marked as > "provided". > > -- > Christopher L Tubbs II > http://gravatar.com/ctubbsii > > > On Tue, May 14, 2013 at 7:09 PM, Benson Margulies > wrote: >> I just doesn't make very much sense to me to have two different GAV's >> for the very same .class files, just to get different dependencies in >> the poms. However, if someone really wanted that, I'd look to make >> some scripting that created this downstream from the main build. >> >> >> On Tue, May 14, 2013 at 6:16 PM, John Vines wrote: >>> They're the same currently. I was requesting separate gavs for hadoop 2. >>> It's been on the mailing list and jira. >>> >>> Sent from my phone, please pardon the typos and brevity. >>> On May 14, 2013 6:14 PM, "Keith Turner" wrote: >>> On Tue, May 14, 2013 at 5:51 PM, Benson Margulies >>> >wrote: > I am a maven developer, and I'm offering this advice based on my > understanding of reason why that generic advice is offered. > > If you have different profiles that _build different results_ but all > deliver the same GAV, you have chaos. > What GAV are we currently producing for hadoop 1 and hadoop 2? > > If you have different profiles that test against different versions of > dependencies, but all deliver the same byte code at the end of the > day, you don't have chaos. > > > > On Tue, May 14, 2013 at 5:48 PM, Christopher wrote: > > I think it's interesting that Option 4 seems to be most preferred... > > because it's the *only* option that is explicitly advised against by > > the Maven developers (from the information I've read). I can see its > > appeal, but I really don't think that we should introduce an explicit > > problem for users (that applies to users using even the Hadoop version > > we directly build against... not just those using Hadoop 2... I don't > > know if that point was clear), to only partially support a version of > > Hadoop that is still alpha and has never had a stable release. > > > > BTW, Option 4 was how I had have achieved a solution for > > ACCUMULO-1402, but am reluctant to apply that patch, with this issue > > outstanding, as it may exacerbate the problem. > > > > Another implication for Option 4 (the current "solution") is for > > 1.6.0, with the planned accumulo-maven-plugin... because it means that > > the accumulo-maven-plugin will need to be configured like this: > > > > org.apache.accumulo > > accumulo-maven-plugin > > > >... all the required hadoop 1 dependencies to make the plugin work, > > even though this version only works against hadoop 1 anyway... > > > > ... > > > > > > -- > > Christopher L Tubbs II > > http://gravatar.com/ctubbsii > > > > > > On Tue, May 14, 2013 at 5:42 PM, Christopher > wrote: > >> I think Option 2 is the best solution for "waiting until we have the > >> time to solve the problem correctly", as it ensures that transitive > >> dependencies work for the stable version of Hadoop, and using Hadoop2 > >> is a very simple documentation issue for how to apply the patch and > >> rebuild. Option 4 doesn't wait... it explicitly introduces a problem > >> for users. > >> > >> Option 1 is how I'm tentatively thinking about fixing it properly in > 1.6.0. > >> > >> > >> -- > >> Christopher L Tubbs II > >> http://gravatar.com/ctubbsii > >> > >> > >> On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: > >>> I'm an advocate of option 4. You say that it's ignoring the problem, > >>> whereas I think it's waiting until we have the time to solve the > problem > >>> correctly. Your reasoning for this is for standardizing for maven > >>> conventions, but the other options, while more 'correct' from a maven
Re: Hadoop 2 compatibility issues
Benson- They produce different byte-code. That's why we're even considering this. ACCUMULO-1402 is the ticket under which our intent is to add classifiers, so that they can be distinguished. All- To Keith's point, I think perhaps all this concern is a non-issue... because as Keith points out, the dependencies in question are marked as "provided", and dependency resolution doesn't occur for provided dependencies anyway... so even if we leave off the profiles, we're in the same boat. Maybe not the boat we should be in... but certainly not a sinking one as I had first imagined. It's as afloat as it was before, when they were not in a profile, but still marked as "provided". -- Christopher L Tubbs II http://gravatar.com/ctubbsii On Tue, May 14, 2013 at 7:09 PM, Benson Margulies wrote: > I just doesn't make very much sense to me to have two different GAV's > for the very same .class files, just to get different dependencies in > the poms. However, if someone really wanted that, I'd look to make > some scripting that created this downstream from the main build. > > > On Tue, May 14, 2013 at 6:16 PM, John Vines wrote: >> They're the same currently. I was requesting separate gavs for hadoop 2. >> It's been on the mailing list and jira. >> >> Sent from my phone, please pardon the typos and brevity. >> On May 14, 2013 6:14 PM, "Keith Turner" wrote: >> >>> On Tue, May 14, 2013 at 5:51 PM, Benson Margulies >> >wrote: >>> >>> > I am a maven developer, and I'm offering this advice based on my >>> > understanding of reason why that generic advice is offered. >>> > >>> > If you have different profiles that _build different results_ but all >>> > deliver the same GAV, you have chaos. >>> > >>> >>> What GAV are we currently producing for hadoop 1 and hadoop 2? >>> >>> >>> > >>> > If you have different profiles that test against different versions of >>> > dependencies, but all deliver the same byte code at the end of the >>> > day, you don't have chaos. >>> > >>> > >>> > >>> > On Tue, May 14, 2013 at 5:48 PM, Christopher >>> wrote: >>> > > I think it's interesting that Option 4 seems to be most preferred... >>> > > because it's the *only* option that is explicitly advised against by >>> > > the Maven developers (from the information I've read). I can see its >>> > > appeal, but I really don't think that we should introduce an explicit >>> > > problem for users (that applies to users using even the Hadoop version >>> > > we directly build against... not just those using Hadoop 2... I don't >>> > > know if that point was clear), to only partially support a version of >>> > > Hadoop that is still alpha and has never had a stable release. >>> > > >>> > > BTW, Option 4 was how I had have achieved a solution for >>> > > ACCUMULO-1402, but am reluctant to apply that patch, with this issue >>> > > outstanding, as it may exacerbate the problem. >>> > > >>> > > Another implication for Option 4 (the current "solution") is for >>> > > 1.6.0, with the planned accumulo-maven-plugin... because it means that >>> > > the accumulo-maven-plugin will need to be configured like this: >>> > > >>> > > org.apache.accumulo >>> > > accumulo-maven-plugin >>> > > >>> > >... all the required hadoop 1 dependencies to make the plugin work, >>> > > even though this version only works against hadoop 1 anyway... >>> > > >>> > > ... >>> > > >>> > > >>> > > -- >>> > > Christopher L Tubbs II >>> > > http://gravatar.com/ctubbsii >>> > > >>> > > >>> > > On Tue, May 14, 2013 at 5:42 PM, Christopher >>> > wrote: >>> > >> I think Option 2 is the best solution for "waiting until we have the >>> > >> time to solve the problem correctly", as it ensures that transitive >>> > >> dependencies work for the stable version of Hadoop, and using Hadoop2 >>> > >> is a very simple documentation issue for how to apply the patch and >>> > >> rebuild. Option 4 doesn't wait... it explicitly introduces a problem >>> > >> for users. >>> > >> >>> > >> Option 1 is how I'm tentatively thinking about fixing it properly in >>> > 1.6.0. >>> > >> >>> > >> >>> > >> -- >>> > >> Christopher L Tubbs II >>> > >> http://gravatar.com/ctubbsii >>> > >> >>> > >> >>> > >> On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: >>> > >>> I'm an advocate of option 4. You say that it's ignoring the problem, >>> > >>> whereas I think it's waiting until we have the time to solve the >>> > problem >>> > >>> correctly. Your reasoning for this is for standardizing for maven >>> > >>> conventions, but the other options, while more 'correct' from a maven >>> > >>> standpoint or a larger headache for our user base and ourselves. In >>> > either >>> > >>> case, we're going to be breaking some sort of convention, and while >>> > it's >>> > >>> not good, we should be doing the one that's less bad for US. The >>> > important >>> > >>> thing here, now, is that the poms work and we should go with the >>> method >>> > >>> that leaves the work minimal for our end users to utilize them. >>> > >>
Re: Hadoop 2 compatibility issues
I'm not sure what the "best" solution would be, but I'd easily assume any worthwhile solution would extend the 1.5.0 release date even farther than I'd be happy about. So, by that stance, I'm for #4 or another quick fix, even if it does perpetuate some sort of "hack". On 05/14/2013 07:09 PM, Benson Margulies wrote: I just doesn't make very much sense to me to have two different GAV's for the very same .class files, just to get different dependencies in the poms. However, if someone really wanted that, I'd look to make some scripting that created this downstream from the main build. This makes sense to me. Although, I don't know exactly how one would go about doing this, I trust Benson enough not to throw something non-feasible at us :)
Re: Hadoop 2 compatibility issues
Thanks Christopher for looking into this with your usual determination and thoroughness. -Eric On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: > So, I've run into a problem with ACCUMULO-1402 that requires a larger > discussion about how Accumulo 1.5.0 should support Hadoop2. > > The problem is basically that profiles should not contain > dependencies, because profiles don't get activated transitively. A > slide deck by the Maven developers point this out as a bad practice... > yet it's a practice we rely on for our current implementation of > Hadoop2 support > (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > slide 80). > > What this means is that even if we go through the work of publishing > binary artifacts compiled against Hadoop2, neither our Hadoop1 > binaries or our Hadoop2 binaries will be able to transitively resolve > any dependencies defined in profiles. This has significant > implications to user code that depends on Accumulo Maven artifacts. > Every user will essentially have to explicitly add Hadoop dependencies > for every Accumulo artifact that has dependencies on Hadoop, either > because we directly or transitively depend on Hadoop (they'll have to > peek into the profiles in our POMs and copy/paste the profile into > their project). This becomes more complicated when we consider how > users will try to use things like Instamo. > > There are workarounds, but none of them are really pleasant. > > 1. The best way to support both major Hadoop APIs is to have separate > modules with separate dependencies directly in the POM. This is a fair > amount of work, and in my opinion, would be too disruptive for 1.5.0. > This solution also gets us separate binaries for separate supported > versions, which is useful. > > 2. A second option, and the preferred one I think for 1.5.0, is to put > a Hadoop2 patch in the branch's contrib directory > (branches/1.5/contrib) that patches the POM files to support building > against Hadoop2. (Acknowledgement to Keith for suggesting this > solution.) > > 3. A third option is to fork Accumulo, and maintain two separate > builds (a more traditional technique). This adds merging nightmare for > features/patches, but gets around some reflection hacks that we may > have been motivated to do in the past. I'm not a fan of this option, > particularly because I don't want to replicate the fork nightmare that > has been the history of early Hadoop itself. > > 4. The last option is to do nothing and to continue to build with the > separate profiles as we are, and make users discover and specify > transitive dependencies entirely on their own. I think this is the > worst option, as it essentially amounts to "ignore the problem". > > At the very least, it does not seem reasonable to complete > ACCUMULO-1402 for 1.5.0, given the complexity of this issue. > > Thoughts? Discussion? Vote on option? > > -- > Christopher L Tubbs II > http://gravatar.com/ctubbsii >
Re: Hadoop 2 compatibility issues
I just doesn't make very much sense to me to have two different GAV's for the very same .class files, just to get different dependencies in the poms. However, if someone really wanted that, I'd look to make some scripting that created this downstream from the main build. On Tue, May 14, 2013 at 6:16 PM, John Vines wrote: > They're the same currently. I was requesting separate gavs for hadoop 2. > It's been on the mailing list and jira. > > Sent from my phone, please pardon the typos and brevity. > On May 14, 2013 6:14 PM, "Keith Turner" wrote: > >> On Tue, May 14, 2013 at 5:51 PM, Benson Margulies > >wrote: >> >> > I am a maven developer, and I'm offering this advice based on my >> > understanding of reason why that generic advice is offered. >> > >> > If you have different profiles that _build different results_ but all >> > deliver the same GAV, you have chaos. >> > >> >> What GAV are we currently producing for hadoop 1 and hadoop 2? >> >> >> > >> > If you have different profiles that test against different versions of >> > dependencies, but all deliver the same byte code at the end of the >> > day, you don't have chaos. >> > >> > >> > >> > On Tue, May 14, 2013 at 5:48 PM, Christopher >> wrote: >> > > I think it's interesting that Option 4 seems to be most preferred... >> > > because it's the *only* option that is explicitly advised against by >> > > the Maven developers (from the information I've read). I can see its >> > > appeal, but I really don't think that we should introduce an explicit >> > > problem for users (that applies to users using even the Hadoop version >> > > we directly build against... not just those using Hadoop 2... I don't >> > > know if that point was clear), to only partially support a version of >> > > Hadoop that is still alpha and has never had a stable release. >> > > >> > > BTW, Option 4 was how I had have achieved a solution for >> > > ACCUMULO-1402, but am reluctant to apply that patch, with this issue >> > > outstanding, as it may exacerbate the problem. >> > > >> > > Another implication for Option 4 (the current "solution") is for >> > > 1.6.0, with the planned accumulo-maven-plugin... because it means that >> > > the accumulo-maven-plugin will need to be configured like this: >> > > >> > > org.apache.accumulo >> > > accumulo-maven-plugin >> > > >> > >... all the required hadoop 1 dependencies to make the plugin work, >> > > even though this version only works against hadoop 1 anyway... >> > > >> > > ... >> > > >> > > >> > > -- >> > > Christopher L Tubbs II >> > > http://gravatar.com/ctubbsii >> > > >> > > >> > > On Tue, May 14, 2013 at 5:42 PM, Christopher >> > wrote: >> > >> I think Option 2 is the best solution for "waiting until we have the >> > >> time to solve the problem correctly", as it ensures that transitive >> > >> dependencies work for the stable version of Hadoop, and using Hadoop2 >> > >> is a very simple documentation issue for how to apply the patch and >> > >> rebuild. Option 4 doesn't wait... it explicitly introduces a problem >> > >> for users. >> > >> >> > >> Option 1 is how I'm tentatively thinking about fixing it properly in >> > 1.6.0. >> > >> >> > >> >> > >> -- >> > >> Christopher L Tubbs II >> > >> http://gravatar.com/ctubbsii >> > >> >> > >> >> > >> On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: >> > >>> I'm an advocate of option 4. You say that it's ignoring the problem, >> > >>> whereas I think it's waiting until we have the time to solve the >> > problem >> > >>> correctly. Your reasoning for this is for standardizing for maven >> > >>> conventions, but the other options, while more 'correct' from a maven >> > >>> standpoint or a larger headache for our user base and ourselves. In >> > either >> > >>> case, we're going to be breaking some sort of convention, and while >> > it's >> > >>> not good, we should be doing the one that's less bad for US. The >> > important >> > >>> thing here, now, is that the poms work and we should go with the >> method >> > >>> that leaves the work minimal for our end users to utilize them. >> > >>> >> > >>> I do agree that 1. is the correct option in the long run. More >> > >>> specifically, I think it boils down to having a single module >> > compatibility >> > >>> layer, which is how hbase deals with this issue. But like you said, >> we >> > >>> don't have the time to engineer a proper solution. So let sleeping >> > dogs lie >> > >>> and we can revamp the whole system for 1.5.1 or 1.6.0 when we have >> the >> > >>> cycles to do it right. >> > >>> >> > >>> >> > >>> On Tue, May 14, 2013 at 4:40 PM, Christopher >> > wrote: >> > >>> >> > So, I've run into a problem with ACCUMULO-1402 that requires a >> larger >> > discussion about how Accumulo 1.5.0 should support Hadoop2. >> > >> > The problem is basically that profiles should not contain >> > dependencies, because profiles don't get activated transitively. A >> > slide deck by the Maven developers point
Re: Hadoop 2 compatibility issues
They're the same currently. I was requesting separate gavs for hadoop 2. It's been on the mailing list and jira. Sent from my phone, please pardon the typos and brevity. On May 14, 2013 6:14 PM, "Keith Turner" wrote: > On Tue, May 14, 2013 at 5:51 PM, Benson Margulies >wrote: > > > I am a maven developer, and I'm offering this advice based on my > > understanding of reason why that generic advice is offered. > > > > If you have different profiles that _build different results_ but all > > deliver the same GAV, you have chaos. > > > > What GAV are we currently producing for hadoop 1 and hadoop 2? > > > > > > If you have different profiles that test against different versions of > > dependencies, but all deliver the same byte code at the end of the > > day, you don't have chaos. > > > > > > > > On Tue, May 14, 2013 at 5:48 PM, Christopher > wrote: > > > I think it's interesting that Option 4 seems to be most preferred... > > > because it's the *only* option that is explicitly advised against by > > > the Maven developers (from the information I've read). I can see its > > > appeal, but I really don't think that we should introduce an explicit > > > problem for users (that applies to users using even the Hadoop version > > > we directly build against... not just those using Hadoop 2... I don't > > > know if that point was clear), to only partially support a version of > > > Hadoop that is still alpha and has never had a stable release. > > > > > > BTW, Option 4 was how I had have achieved a solution for > > > ACCUMULO-1402, but am reluctant to apply that patch, with this issue > > > outstanding, as it may exacerbate the problem. > > > > > > Another implication for Option 4 (the current "solution") is for > > > 1.6.0, with the planned accumulo-maven-plugin... because it means that > > > the accumulo-maven-plugin will need to be configured like this: > > > > > > org.apache.accumulo > > > accumulo-maven-plugin > > > > > >... all the required hadoop 1 dependencies to make the plugin work, > > > even though this version only works against hadoop 1 anyway... > > > > > > ... > > > > > > > > > -- > > > Christopher L Tubbs II > > > http://gravatar.com/ctubbsii > > > > > > > > > On Tue, May 14, 2013 at 5:42 PM, Christopher > > wrote: > > >> I think Option 2 is the best solution for "waiting until we have the > > >> time to solve the problem correctly", as it ensures that transitive > > >> dependencies work for the stable version of Hadoop, and using Hadoop2 > > >> is a very simple documentation issue for how to apply the patch and > > >> rebuild. Option 4 doesn't wait... it explicitly introduces a problem > > >> for users. > > >> > > >> Option 1 is how I'm tentatively thinking about fixing it properly in > > 1.6.0. > > >> > > >> > > >> -- > > >> Christopher L Tubbs II > > >> http://gravatar.com/ctubbsii > > >> > > >> > > >> On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: > > >>> I'm an advocate of option 4. You say that it's ignoring the problem, > > >>> whereas I think it's waiting until we have the time to solve the > > problem > > >>> correctly. Your reasoning for this is for standardizing for maven > > >>> conventions, but the other options, while more 'correct' from a maven > > >>> standpoint or a larger headache for our user base and ourselves. In > > either > > >>> case, we're going to be breaking some sort of convention, and while > > it's > > >>> not good, we should be doing the one that's less bad for US. The > > important > > >>> thing here, now, is that the poms work and we should go with the > method > > >>> that leaves the work minimal for our end users to utilize them. > > >>> > > >>> I do agree that 1. is the correct option in the long run. More > > >>> specifically, I think it boils down to having a single module > > compatibility > > >>> layer, which is how hbase deals with this issue. But like you said, > we > > >>> don't have the time to engineer a proper solution. So let sleeping > > dogs lie > > >>> and we can revamp the whole system for 1.5.1 or 1.6.0 when we have > the > > >>> cycles to do it right. > > >>> > > >>> > > >>> On Tue, May 14, 2013 at 4:40 PM, Christopher > > wrote: > > >>> > > So, I've run into a problem with ACCUMULO-1402 that requires a > larger > > discussion about how Accumulo 1.5.0 should support Hadoop2. > > > > The problem is basically that profiles should not contain > > dependencies, because profiles don't get activated transitively. A > > slide deck by the Maven developers point this out as a bad > practice... > > yet it's a practice we rely on for our current implementation of > > Hadoop2 support > > ( > http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > > slide 80). > > > > What this means is that even if we go through the work of publishing > > binary artifacts compiled against Hadoop2, neither our Hadoop1 > > binaries or our Hadoop2 binaries will be ab
Re: Hadoop 2 compatibility issues
This is part of my thinking. All of the dependencies included in the profiles for Avro are marked provided. Provided scope, by definition, is not transitive. Thus, it doesn't really matter that they aren't transitive *also* because of the profile. Is Accumulo including anything other than things provided by either Hadoop 1 or 2? On Tue, May 14, 2013 at 6:08 PM, Keith Turner wrote: > One note about option 4. When using 1.4 users have to include hadoop core > as a dependency in their pom. This must be done because the 1.4 Accumulo > pom marks hadoop-core as provided. So maybe option 4 is ok if the deps in > the profile are provided? > > > On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: > > > So, I've run into a problem with ACCUMULO-1402 that requires a larger > > discussion about how Accumulo 1.5.0 should support Hadoop2. > > > > The problem is basically that profiles should not contain > > dependencies, because profiles don't get activated transitively. A > > slide deck by the Maven developers point this out as a bad practice... > > yet it's a practice we rely on for our current implementation of > > Hadoop2 support > > (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > > slide 80). > > > > What this means is that even if we go through the work of publishing > > binary artifacts compiled against Hadoop2, neither our Hadoop1 > > binaries or our Hadoop2 binaries will be able to transitively resolve > > any dependencies defined in profiles. This has significant > > implications to user code that depends on Accumulo Maven artifacts. > > Every user will essentially have to explicitly add Hadoop dependencies > > for every Accumulo artifact that has dependencies on Hadoop, either > > because we directly or transitively depend on Hadoop (they'll have to > > peek into the profiles in our POMs and copy/paste the profile into > > their project). This becomes more complicated when we consider how > > users will try to use things like Instamo. > > > > There are workarounds, but none of them are really pleasant. > > > > 1. The best way to support both major Hadoop APIs is to have separate > > modules with separate dependencies directly in the POM. This is a fair > > amount of work, and in my opinion, would be too disruptive for 1.5.0. > > This solution also gets us separate binaries for separate supported > > versions, which is useful. > > > > 2. A second option, and the preferred one I think for 1.5.0, is to put > > a Hadoop2 patch in the branch's contrib directory > > (branches/1.5/contrib) that patches the POM files to support building > > against Hadoop2. (Acknowledgement to Keith for suggesting this > > solution.) > > > > 3. A third option is to fork Accumulo, and maintain two separate > > builds (a more traditional technique). This adds merging nightmare for > > features/patches, but gets around some reflection hacks that we may > > have been motivated to do in the past. I'm not a fan of this option, > > particularly because I don't want to replicate the fork nightmare that > > has been the history of early Hadoop itself. > > > > 4. The last option is to do nothing and to continue to build with the > > separate profiles as we are, and make users discover and specify > > transitive dependencies entirely on their own. I think this is the > > worst option, as it essentially amounts to "ignore the problem". > > > > At the very least, it does not seem reasonable to complete > > ACCUMULO-1402 for 1.5.0, given the complexity of this issue. > > > > Thoughts? Discussion? Vote on option? > > > > -- > > Christopher L Tubbs II > > http://gravatar.com/ctubbsii > > > -- Sean
Re: Hadoop 2 compatibility issues
On Tue, May 14, 2013 at 5:51 PM, Benson Margulies wrote: > I am a maven developer, and I'm offering this advice based on my > understanding of reason why that generic advice is offered. > > If you have different profiles that _build different results_ but all > deliver the same GAV, you have chaos. > What GAV are we currently producing for hadoop 1 and hadoop 2? > > If you have different profiles that test against different versions of > dependencies, but all deliver the same byte code at the end of the > day, you don't have chaos. > > > > On Tue, May 14, 2013 at 5:48 PM, Christopher wrote: > > I think it's interesting that Option 4 seems to be most preferred... > > because it's the *only* option that is explicitly advised against by > > the Maven developers (from the information I've read). I can see its > > appeal, but I really don't think that we should introduce an explicit > > problem for users (that applies to users using even the Hadoop version > > we directly build against... not just those using Hadoop 2... I don't > > know if that point was clear), to only partially support a version of > > Hadoop that is still alpha and has never had a stable release. > > > > BTW, Option 4 was how I had have achieved a solution for > > ACCUMULO-1402, but am reluctant to apply that patch, with this issue > > outstanding, as it may exacerbate the problem. > > > > Another implication for Option 4 (the current "solution") is for > > 1.6.0, with the planned accumulo-maven-plugin... because it means that > > the accumulo-maven-plugin will need to be configured like this: > > > > org.apache.accumulo > > accumulo-maven-plugin > > > >... all the required hadoop 1 dependencies to make the plugin work, > > even though this version only works against hadoop 1 anyway... > > > > ... > > > > > > -- > > Christopher L Tubbs II > > http://gravatar.com/ctubbsii > > > > > > On Tue, May 14, 2013 at 5:42 PM, Christopher > wrote: > >> I think Option 2 is the best solution for "waiting until we have the > >> time to solve the problem correctly", as it ensures that transitive > >> dependencies work for the stable version of Hadoop, and using Hadoop2 > >> is a very simple documentation issue for how to apply the patch and > >> rebuild. Option 4 doesn't wait... it explicitly introduces a problem > >> for users. > >> > >> Option 1 is how I'm tentatively thinking about fixing it properly in > 1.6.0. > >> > >> > >> -- > >> Christopher L Tubbs II > >> http://gravatar.com/ctubbsii > >> > >> > >> On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: > >>> I'm an advocate of option 4. You say that it's ignoring the problem, > >>> whereas I think it's waiting until we have the time to solve the > problem > >>> correctly. Your reasoning for this is for standardizing for maven > >>> conventions, but the other options, while more 'correct' from a maven > >>> standpoint or a larger headache for our user base and ourselves. In > either > >>> case, we're going to be breaking some sort of convention, and while > it's > >>> not good, we should be doing the one that's less bad for US. The > important > >>> thing here, now, is that the poms work and we should go with the method > >>> that leaves the work minimal for our end users to utilize them. > >>> > >>> I do agree that 1. is the correct option in the long run. More > >>> specifically, I think it boils down to having a single module > compatibility > >>> layer, which is how hbase deals with this issue. But like you said, we > >>> don't have the time to engineer a proper solution. So let sleeping > dogs lie > >>> and we can revamp the whole system for 1.5.1 or 1.6.0 when we have the > >>> cycles to do it right. > >>> > >>> > >>> On Tue, May 14, 2013 at 4:40 PM, Christopher > wrote: > >>> > So, I've run into a problem with ACCUMULO-1402 that requires a larger > discussion about how Accumulo 1.5.0 should support Hadoop2. > > The problem is basically that profiles should not contain > dependencies, because profiles don't get activated transitively. A > slide deck by the Maven developers point this out as a bad practice... > yet it's a practice we rely on for our current implementation of > Hadoop2 support > (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > slide 80). > > What this means is that even if we go through the work of publishing > binary artifacts compiled against Hadoop2, neither our Hadoop1 > binaries or our Hadoop2 binaries will be able to transitively resolve > any dependencies defined in profiles. This has significant > implications to user code that depends on Accumulo Maven artifacts. > Every user will essentially have to explicitly add Hadoop dependencies > for every Accumulo artifact that has dependencies on Hadoop, either > because we directly or transitively depend on Hadoop (they'll have to > peek into the profiles in our POMs and copy/paste
Re: Hadoop 2 compatibility issues - tangent
On that note, I was wondering if there were any suggestions for how to deal with the laundry list of provided dependencies that Accumulo core has? Writing packages against it is a bit ugly if not using the accumulo script to start. Are there any maven utilities to automatically dissect provided dependencies and make them included. Sent from my phone, please pardon the typos and brevity. On May 14, 2013 6:09 PM, "Keith Turner" wrote: > One note about option 4. When using 1.4 users have to include hadoop core > as a dependency in their pom. This must be done because the 1.4 Accumulo > pom marks hadoop-core as provided. So maybe option 4 is ok if the deps in > the profile are provided? > > > On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: > > > So, I've run into a problem with ACCUMULO-1402 that requires a larger > > discussion about how Accumulo 1.5.0 should support Hadoop2. > > > > The problem is basically that profiles should not contain > > dependencies, because profiles don't get activated transitively. A > > slide deck by the Maven developers point this out as a bad practice... > > yet it's a practice we rely on for our current implementation of > > Hadoop2 support > > (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > > slide 80). > > > > What this means is that even if we go through the work of publishing > > binary artifacts compiled against Hadoop2, neither our Hadoop1 > > binaries or our Hadoop2 binaries will be able to transitively resolve > > any dependencies defined in profiles. This has significant > > implications to user code that depends on Accumulo Maven artifacts. > > Every user will essentially have to explicitly add Hadoop dependencies > > for every Accumulo artifact that has dependencies on Hadoop, either > > because we directly or transitively depend on Hadoop (they'll have to > > peek into the profiles in our POMs and copy/paste the profile into > > their project). This becomes more complicated when we consider how > > users will try to use things like Instamo. > > > > There are workarounds, but none of them are really pleasant. > > > > 1. The best way to support both major Hadoop APIs is to have separate > > modules with separate dependencies directly in the POM. This is a fair > > amount of work, and in my opinion, would be too disruptive for 1.5.0. > > This solution also gets us separate binaries for separate supported > > versions, which is useful. > > > > 2. A second option, and the preferred one I think for 1.5.0, is to put > > a Hadoop2 patch in the branch's contrib directory > > (branches/1.5/contrib) that patches the POM files to support building > > against Hadoop2. (Acknowledgement to Keith for suggesting this > > solution.) > > > > 3. A third option is to fork Accumulo, and maintain two separate > > builds (a more traditional technique). This adds merging nightmare for > > features/patches, but gets around some reflection hacks that we may > > have been motivated to do in the past. I'm not a fan of this option, > > particularly because I don't want to replicate the fork nightmare that > > has been the history of early Hadoop itself. > > > > 4. The last option is to do nothing and to continue to build with the > > separate profiles as we are, and make users discover and specify > > transitive dependencies entirely on their own. I think this is the > > worst option, as it essentially amounts to "ignore the problem". > > > > At the very least, it does not seem reasonable to complete > > ACCUMULO-1402 for 1.5.0, given the complexity of this issue. > > > > Thoughts? Discussion? Vote on option? > > > > -- > > Christopher L Tubbs II > > http://gravatar.com/ctubbsii > > >
Re: Hadoop 2 compatibility issues
One note about option 4. When using 1.4 users have to include hadoop core as a dependency in their pom. This must be done because the 1.4 Accumulo pom marks hadoop-core as provided. So maybe option 4 is ok if the deps in the profile are provided? On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: > So, I've run into a problem with ACCUMULO-1402 that requires a larger > discussion about how Accumulo 1.5.0 should support Hadoop2. > > The problem is basically that profiles should not contain > dependencies, because profiles don't get activated transitively. A > slide deck by the Maven developers point this out as a bad practice... > yet it's a practice we rely on for our current implementation of > Hadoop2 support > (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > slide 80). > > What this means is that even if we go through the work of publishing > binary artifacts compiled against Hadoop2, neither our Hadoop1 > binaries or our Hadoop2 binaries will be able to transitively resolve > any dependencies defined in profiles. This has significant > implications to user code that depends on Accumulo Maven artifacts. > Every user will essentially have to explicitly add Hadoop dependencies > for every Accumulo artifact that has dependencies on Hadoop, either > because we directly or transitively depend on Hadoop (they'll have to > peek into the profiles in our POMs and copy/paste the profile into > their project). This becomes more complicated when we consider how > users will try to use things like Instamo. > > There are workarounds, but none of them are really pleasant. > > 1. The best way to support both major Hadoop APIs is to have separate > modules with separate dependencies directly in the POM. This is a fair > amount of work, and in my opinion, would be too disruptive for 1.5.0. > This solution also gets us separate binaries for separate supported > versions, which is useful. > > 2. A second option, and the preferred one I think for 1.5.0, is to put > a Hadoop2 patch in the branch's contrib directory > (branches/1.5/contrib) that patches the POM files to support building > against Hadoop2. (Acknowledgement to Keith for suggesting this > solution.) > > 3. A third option is to fork Accumulo, and maintain two separate > builds (a more traditional technique). This adds merging nightmare for > features/patches, but gets around some reflection hacks that we may > have been motivated to do in the past. I'm not a fan of this option, > particularly because I don't want to replicate the fork nightmare that > has been the history of early Hadoop itself. > > 4. The last option is to do nothing and to continue to build with the > separate profiles as we are, and make users discover and specify > transitive dependencies entirely on their own. I think this is the > worst option, as it essentially amounts to "ignore the problem". > > At the very least, it does not seem reasonable to complete > ACCUMULO-1402 for 1.5.0, given the complexity of this issue. > > Thoughts? Discussion? Vote on option? > > -- > Christopher L Tubbs II > http://gravatar.com/ctubbsii >
Re: Hadoop 2 compatibility issues
You're so quick to dismiss hadoop 2,but you really need to keep in mind how pervasive it is. Even from our own software we can see how much people love to run off of trunk, let alpha releases. But then one of the most popular distributions, cdh, is more in line with it as well. Something to keep in mind is that cdh3u5+ has hell of a lot in common with Hadoop 2 rather that hadoop 1,with regard to api compatibilities. I'm sorry, but that's a user base I would rather have some "unconventional" build code to support rather than create an unnecessary headache for them and ourselves. Sent from my phone, please pardon the typos and brevity. On May 14, 2013 5:48 PM, "Christopher" wrote: > I think it's interesting that Option 4 seems to be most preferred... > because it's the *only* option that is explicitly advised against by > the Maven developers (from the information I've read). I can see its > appeal, but I really don't think that we should introduce an explicit > problem for users (that applies to users using even the Hadoop version > we directly build against... not just those using Hadoop 2... I don't > know if that point was clear), to only partially support a version of > Hadoop that is still alpha and has never had a stable release. > > BTW, Option 4 was how I had have achieved a solution for > ACCUMULO-1402, but am reluctant to apply that patch, with this issue > outstanding, as it may exacerbate the problem. > > Another implication for Option 4 (the current "solution") is for > 1.6.0, with the planned accumulo-maven-plugin... because it means that > the accumulo-maven-plugin will need to be configured like this: > > org.apache.accumulo > accumulo-maven-plugin > >... all the required hadoop 1 dependencies to make the plugin work, > even though this version only works against hadoop 1 anyway... > > ... > > > -- > Christopher L Tubbs II > http://gravatar.com/ctubbsii > > > On Tue, May 14, 2013 at 5:42 PM, Christopher wrote: > > I think Option 2 is the best solution for "waiting until we have the > > time to solve the problem correctly", as it ensures that transitive > > dependencies work for the stable version of Hadoop, and using Hadoop2 > > is a very simple documentation issue for how to apply the patch and > > rebuild. Option 4 doesn't wait... it explicitly introduces a problem > > for users. > > > > Option 1 is how I'm tentatively thinking about fixing it properly in > 1.6.0. > > > > > > -- > > Christopher L Tubbs II > > http://gravatar.com/ctubbsii > > > > > > On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: > >> I'm an advocate of option 4. You say that it's ignoring the problem, > >> whereas I think it's waiting until we have the time to solve the problem > >> correctly. Your reasoning for this is for standardizing for maven > >> conventions, but the other options, while more 'correct' from a maven > >> standpoint or a larger headache for our user base and ourselves. In > either > >> case, we're going to be breaking some sort of convention, and while it's > >> not good, we should be doing the one that's less bad for US. The > important > >> thing here, now, is that the poms work and we should go with the method > >> that leaves the work minimal for our end users to utilize them. > >> > >> I do agree that 1. is the correct option in the long run. More > >> specifically, I think it boils down to having a single module > compatibility > >> layer, which is how hbase deals with this issue. But like you said, we > >> don't have the time to engineer a proper solution. So let sleeping dogs > lie > >> and we can revamp the whole system for 1.5.1 or 1.6.0 when we have the > >> cycles to do it right. > >> > >> > >> On Tue, May 14, 2013 at 4:40 PM, Christopher > wrote: > >> > >>> So, I've run into a problem with ACCUMULO-1402 that requires a larger > >>> discussion about how Accumulo 1.5.0 should support Hadoop2. > >>> > >>> The problem is basically that profiles should not contain > >>> dependencies, because profiles don't get activated transitively. A > >>> slide deck by the Maven developers point this out as a bad practice... > >>> yet it's a practice we rely on for our current implementation of > >>> Hadoop2 support > >>> (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > >>> slide 80). > >>> > >>> What this means is that even if we go through the work of publishing > >>> binary artifacts compiled against Hadoop2, neither our Hadoop1 > >>> binaries or our Hadoop2 binaries will be able to transitively resolve > >>> any dependencies defined in profiles. This has significant > >>> implications to user code that depends on Accumulo Maven artifacts. > >>> Every user will essentially have to explicitly add Hadoop dependencies > >>> for every Accumulo artifact that has dependencies on Hadoop, either > >>> because we directly or transitively depend on Hadoop (they'll have to > >>> peek into the profiles in our POMs and copy/paste the profile into > >>> their project).
Re: Hadoop 2 compatibility issues
We can easily fix the break it the hadoop dependencies by making the switch to hadoop-client and relying on hadoop.version to set/override the version. The hadoop 2 profile is just needed to bring in additional dependencies and possibly setting the hadoop version for convenience. Sent from my phone, please pardon the typos and brevity. On May 14, 2013 5:48 PM, "Christopher" wrote: > I think it's interesting that Option 4 seems to be most preferred... > because it's the *only* option that is explicitly advised against by > the Maven developers (from the information I've read). I can see its > appeal, but I really don't think that we should introduce an explicit > problem for users (that applies to users using even the Hadoop version > we directly build against... not just those using Hadoop 2... I don't > know if that point was clear), to only partially support a version of > Hadoop that is still alpha and has never had a stable release. > > BTW, Option 4 was how I had have achieved a solution for > ACCUMULO-1402, but am reluctant to apply that patch, with this issue > outstanding, as it may exacerbate the problem. > > Another implication for Option 4 (the current "solution") is for > 1.6.0, with the planned accumulo-maven-plugin... because it means that > the accumulo-maven-plugin will need to be configured like this: > > org.apache.accumulo > accumulo-maven-plugin > >... all the required hadoop 1 dependencies to make the plugin work, > even though this version only works against hadoop 1 anyway... > > ... > > > -- > Christopher L Tubbs II > http://gravatar.com/ctubbsii > > > On Tue, May 14, 2013 at 5:42 PM, Christopher wrote: > > I think Option 2 is the best solution for "waiting until we have the > > time to solve the problem correctly", as it ensures that transitive > > dependencies work for the stable version of Hadoop, and using Hadoop2 > > is a very simple documentation issue for how to apply the patch and > > rebuild. Option 4 doesn't wait... it explicitly introduces a problem > > for users. > > > > Option 1 is how I'm tentatively thinking about fixing it properly in > 1.6.0. > > > > > > -- > > Christopher L Tubbs II > > http://gravatar.com/ctubbsii > > > > > > On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: > >> I'm an advocate of option 4. You say that it's ignoring the problem, > >> whereas I think it's waiting until we have the time to solve the problem > >> correctly. Your reasoning for this is for standardizing for maven > >> conventions, but the other options, while more 'correct' from a maven > >> standpoint or a larger headache for our user base and ourselves. In > either > >> case, we're going to be breaking some sort of convention, and while it's > >> not good, we should be doing the one that's less bad for US. The > important > >> thing here, now, is that the poms work and we should go with the method > >> that leaves the work minimal for our end users to utilize them. > >> > >> I do agree that 1. is the correct option in the long run. More > >> specifically, I think it boils down to having a single module > compatibility > >> layer, which is how hbase deals with this issue. But like you said, we > >> don't have the time to engineer a proper solution. So let sleeping dogs > lie > >> and we can revamp the whole system for 1.5.1 or 1.6.0 when we have the > >> cycles to do it right. > >> > >> > >> On Tue, May 14, 2013 at 4:40 PM, Christopher > wrote: > >> > >>> So, I've run into a problem with ACCUMULO-1402 that requires a larger > >>> discussion about how Accumulo 1.5.0 should support Hadoop2. > >>> > >>> The problem is basically that profiles should not contain > >>> dependencies, because profiles don't get activated transitively. A > >>> slide deck by the Maven developers point this out as a bad practice... > >>> yet it's a practice we rely on for our current implementation of > >>> Hadoop2 support > >>> (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > >>> slide 80). > >>> > >>> What this means is that even if we go through the work of publishing > >>> binary artifacts compiled against Hadoop2, neither our Hadoop1 > >>> binaries or our Hadoop2 binaries will be able to transitively resolve > >>> any dependencies defined in profiles. This has significant > >>> implications to user code that depends on Accumulo Maven artifacts. > >>> Every user will essentially have to explicitly add Hadoop dependencies > >>> for every Accumulo artifact that has dependencies on Hadoop, either > >>> because we directly or transitively depend on Hadoop (they'll have to > >>> peek into the profiles in our POMs and copy/paste the profile into > >>> their project). This becomes more complicated when we consider how > >>> users will try to use things like Instamo. > >>> > >>> There are workarounds, but none of them are really pleasant. > >>> > >>> 1. The best way to support both major Hadoop APIs is to have separate > >>> modules with separate dependencies directl
Re: Hadoop 2 compatibility issues
I am a maven developer, and I'm offering this advice based on my understanding of reason why that generic advice is offered. If you have different profiles that _build different results_ but all deliver the same GAV, you have chaos. If you have different profiles that test against different versions of dependencies, but all deliver the same byte code at the end of the day, you don't have chaos. On Tue, May 14, 2013 at 5:48 PM, Christopher wrote: > I think it's interesting that Option 4 seems to be most preferred... > because it's the *only* option that is explicitly advised against by > the Maven developers (from the information I've read). I can see its > appeal, but I really don't think that we should introduce an explicit > problem for users (that applies to users using even the Hadoop version > we directly build against... not just those using Hadoop 2... I don't > know if that point was clear), to only partially support a version of > Hadoop that is still alpha and has never had a stable release. > > BTW, Option 4 was how I had have achieved a solution for > ACCUMULO-1402, but am reluctant to apply that patch, with this issue > outstanding, as it may exacerbate the problem. > > Another implication for Option 4 (the current "solution") is for > 1.6.0, with the planned accumulo-maven-plugin... because it means that > the accumulo-maven-plugin will need to be configured like this: > > org.apache.accumulo > accumulo-maven-plugin > >... all the required hadoop 1 dependencies to make the plugin work, > even though this version only works against hadoop 1 anyway... > > ... > > > -- > Christopher L Tubbs II > http://gravatar.com/ctubbsii > > > On Tue, May 14, 2013 at 5:42 PM, Christopher wrote: >> I think Option 2 is the best solution for "waiting until we have the >> time to solve the problem correctly", as it ensures that transitive >> dependencies work for the stable version of Hadoop, and using Hadoop2 >> is a very simple documentation issue for how to apply the patch and >> rebuild. Option 4 doesn't wait... it explicitly introduces a problem >> for users. >> >> Option 1 is how I'm tentatively thinking about fixing it properly in 1.6.0. >> >> >> -- >> Christopher L Tubbs II >> http://gravatar.com/ctubbsii >> >> >> On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: >>> I'm an advocate of option 4. You say that it's ignoring the problem, >>> whereas I think it's waiting until we have the time to solve the problem >>> correctly. Your reasoning for this is for standardizing for maven >>> conventions, but the other options, while more 'correct' from a maven >>> standpoint or a larger headache for our user base and ourselves. In either >>> case, we're going to be breaking some sort of convention, and while it's >>> not good, we should be doing the one that's less bad for US. The important >>> thing here, now, is that the poms work and we should go with the method >>> that leaves the work minimal for our end users to utilize them. >>> >>> I do agree that 1. is the correct option in the long run. More >>> specifically, I think it boils down to having a single module compatibility >>> layer, which is how hbase deals with this issue. But like you said, we >>> don't have the time to engineer a proper solution. So let sleeping dogs lie >>> and we can revamp the whole system for 1.5.1 or 1.6.0 when we have the >>> cycles to do it right. >>> >>> >>> On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: >>> So, I've run into a problem with ACCUMULO-1402 that requires a larger discussion about how Accumulo 1.5.0 should support Hadoop2. The problem is basically that profiles should not contain dependencies, because profiles don't get activated transitively. A slide deck by the Maven developers point this out as a bad practice... yet it's a practice we rely on for our current implementation of Hadoop2 support (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven slide 80). What this means is that even if we go through the work of publishing binary artifacts compiled against Hadoop2, neither our Hadoop1 binaries or our Hadoop2 binaries will be able to transitively resolve any dependencies defined in profiles. This has significant implications to user code that depends on Accumulo Maven artifacts. Every user will essentially have to explicitly add Hadoop dependencies for every Accumulo artifact that has dependencies on Hadoop, either because we directly or transitively depend on Hadoop (they'll have to peek into the profiles in our POMs and copy/paste the profile into their project). This becomes more complicated when we consider how users will try to use things like Instamo. There are workarounds, but none of them are really pleasant. 1. The best way to support both major Hadoop APIs is to have separate modules with separate dependencies directly in t
Re: Hadoop 2 compatibility issues
I think it's interesting that Option 4 seems to be most preferred... because it's the *only* option that is explicitly advised against by the Maven developers (from the information I've read). I can see its appeal, but I really don't think that we should introduce an explicit problem for users (that applies to users using even the Hadoop version we directly build against... not just those using Hadoop 2... I don't know if that point was clear), to only partially support a version of Hadoop that is still alpha and has never had a stable release. BTW, Option 4 was how I had have achieved a solution for ACCUMULO-1402, but am reluctant to apply that patch, with this issue outstanding, as it may exacerbate the problem. Another implication for Option 4 (the current "solution") is for 1.6.0, with the planned accumulo-maven-plugin... because it means that the accumulo-maven-plugin will need to be configured like this: org.apache.accumulo accumulo-maven-plugin ... all the required hadoop 1 dependencies to make the plugin work, even though this version only works against hadoop 1 anyway... ... -- Christopher L Tubbs II http://gravatar.com/ctubbsii On Tue, May 14, 2013 at 5:42 PM, Christopher wrote: > I think Option 2 is the best solution for "waiting until we have the > time to solve the problem correctly", as it ensures that transitive > dependencies work for the stable version of Hadoop, and using Hadoop2 > is a very simple documentation issue for how to apply the patch and > rebuild. Option 4 doesn't wait... it explicitly introduces a problem > for users. > > Option 1 is how I'm tentatively thinking about fixing it properly in 1.6.0. > > > -- > Christopher L Tubbs II > http://gravatar.com/ctubbsii > > > On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: >> I'm an advocate of option 4. You say that it's ignoring the problem, >> whereas I think it's waiting until we have the time to solve the problem >> correctly. Your reasoning for this is for standardizing for maven >> conventions, but the other options, while more 'correct' from a maven >> standpoint or a larger headache for our user base and ourselves. In either >> case, we're going to be breaking some sort of convention, and while it's >> not good, we should be doing the one that's less bad for US. The important >> thing here, now, is that the poms work and we should go with the method >> that leaves the work minimal for our end users to utilize them. >> >> I do agree that 1. is the correct option in the long run. More >> specifically, I think it boils down to having a single module compatibility >> layer, which is how hbase deals with this issue. But like you said, we >> don't have the time to engineer a proper solution. So let sleeping dogs lie >> and we can revamp the whole system for 1.5.1 or 1.6.0 when we have the >> cycles to do it right. >> >> >> On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: >> >>> So, I've run into a problem with ACCUMULO-1402 that requires a larger >>> discussion about how Accumulo 1.5.0 should support Hadoop2. >>> >>> The problem is basically that profiles should not contain >>> dependencies, because profiles don't get activated transitively. A >>> slide deck by the Maven developers point this out as a bad practice... >>> yet it's a practice we rely on for our current implementation of >>> Hadoop2 support >>> (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven >>> slide 80). >>> >>> What this means is that even if we go through the work of publishing >>> binary artifacts compiled against Hadoop2, neither our Hadoop1 >>> binaries or our Hadoop2 binaries will be able to transitively resolve >>> any dependencies defined in profiles. This has significant >>> implications to user code that depends on Accumulo Maven artifacts. >>> Every user will essentially have to explicitly add Hadoop dependencies >>> for every Accumulo artifact that has dependencies on Hadoop, either >>> because we directly or transitively depend on Hadoop (they'll have to >>> peek into the profiles in our POMs and copy/paste the profile into >>> their project). This becomes more complicated when we consider how >>> users will try to use things like Instamo. >>> >>> There are workarounds, but none of them are really pleasant. >>> >>> 1. The best way to support both major Hadoop APIs is to have separate >>> modules with separate dependencies directly in the POM. This is a fair >>> amount of work, and in my opinion, would be too disruptive for 1.5.0. >>> This solution also gets us separate binaries for separate supported >>> versions, which is useful. >>> >>> 2. A second option, and the preferred one I think for 1.5.0, is to put >>> a Hadoop2 patch in the branch's contrib directory >>> (branches/1.5/contrib) that patches the POM files to support building >>> against Hadoop2. (Acknowledgement to Keith for suggesting this >>> solution.) >>> >>> 3. A third option is to fork Accumulo, and maintain two separate >>> builds (a mo
Re: Hadoop 2 compatibility issues
I think Option 2 is the best solution for "waiting until we have the time to solve the problem correctly", as it ensures that transitive dependencies work for the stable version of Hadoop, and using Hadoop2 is a very simple documentation issue for how to apply the patch and rebuild. Option 4 doesn't wait... it explicitly introduces a problem for users. Option 1 is how I'm tentatively thinking about fixing it properly in 1.6.0. -- Christopher L Tubbs II http://gravatar.com/ctubbsii On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: > I'm an advocate of option 4. You say that it's ignoring the problem, > whereas I think it's waiting until we have the time to solve the problem > correctly. Your reasoning for this is for standardizing for maven > conventions, but the other options, while more 'correct' from a maven > standpoint or a larger headache for our user base and ourselves. In either > case, we're going to be breaking some sort of convention, and while it's > not good, we should be doing the one that's less bad for US. The important > thing here, now, is that the poms work and we should go with the method > that leaves the work minimal for our end users to utilize them. > > I do agree that 1. is the correct option in the long run. More > specifically, I think it boils down to having a single module compatibility > layer, which is how hbase deals with this issue. But like you said, we > don't have the time to engineer a proper solution. So let sleeping dogs lie > and we can revamp the whole system for 1.5.1 or 1.6.0 when we have the > cycles to do it right. > > > On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: > >> So, I've run into a problem with ACCUMULO-1402 that requires a larger >> discussion about how Accumulo 1.5.0 should support Hadoop2. >> >> The problem is basically that profiles should not contain >> dependencies, because profiles don't get activated transitively. A >> slide deck by the Maven developers point this out as a bad practice... >> yet it's a practice we rely on for our current implementation of >> Hadoop2 support >> (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven >> slide 80). >> >> What this means is that even if we go through the work of publishing >> binary artifacts compiled against Hadoop2, neither our Hadoop1 >> binaries or our Hadoop2 binaries will be able to transitively resolve >> any dependencies defined in profiles. This has significant >> implications to user code that depends on Accumulo Maven artifacts. >> Every user will essentially have to explicitly add Hadoop dependencies >> for every Accumulo artifact that has dependencies on Hadoop, either >> because we directly or transitively depend on Hadoop (they'll have to >> peek into the profiles in our POMs and copy/paste the profile into >> their project). This becomes more complicated when we consider how >> users will try to use things like Instamo. >> >> There are workarounds, but none of them are really pleasant. >> >> 1. The best way to support both major Hadoop APIs is to have separate >> modules with separate dependencies directly in the POM. This is a fair >> amount of work, and in my opinion, would be too disruptive for 1.5.0. >> This solution also gets us separate binaries for separate supported >> versions, which is useful. >> >> 2. A second option, and the preferred one I think for 1.5.0, is to put >> a Hadoop2 patch in the branch's contrib directory >> (branches/1.5/contrib) that patches the POM files to support building >> against Hadoop2. (Acknowledgement to Keith for suggesting this >> solution.) >> >> 3. A third option is to fork Accumulo, and maintain two separate >> builds (a more traditional technique). This adds merging nightmare for >> features/patches, but gets around some reflection hacks that we may >> have been motivated to do in the past. I'm not a fan of this option, >> particularly because I don't want to replicate the fork nightmare that >> has been the history of early Hadoop itself. >> >> 4. The last option is to do nothing and to continue to build with the >> separate profiles as we are, and make users discover and specify >> transitive dependencies entirely on their own. I think this is the >> worst option, as it essentially amounts to "ignore the problem". >> >> At the very least, it does not seem reasonable to complete >> ACCUMULO-1402 for 1.5.0, given the complexity of this issue. >> >> Thoughts? Discussion? Vote on option? >> >> -- >> Christopher L Tubbs II >> http://gravatar.com/ctubbsii >>
Re: Hadoop 2 compatibility issues
Yes, they should add a dependency on Hadoop, if they use it. The problem isn't just if they use Hadoop classes, though. It is that the dependency is required for any code path where Accumulo requires Hadoop... and this is unknown to the user, because the dependency tree looks like Accumulo has no dependency on Hadoop at all. They certainly won't know which Hadoop jars to add, without deep inspection of Accumulo's profiles. -- Christopher L Tubbs II http://gravatar.com/ctubbsii On Tue, May 14, 2013 at 4:52 PM, Sean Busbey wrote: > If a user is referencing any of the Hadoop classes, aren't they supposed to > add a dependency on the appropriate Hadoop artifact anyways? > > FWIW, option 4 is what Avro does. Their discussion: > > https://issues.apache.org/jira/browse/AVRO-1170 > > > > > On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: > >> So, I've run into a problem with ACCUMULO-1402 that requires a larger >> discussion about how Accumulo 1.5.0 should support Hadoop2. >> >> The problem is basically that profiles should not contain >> dependencies, because profiles don't get activated transitively. A >> slide deck by the Maven developers point this out as a bad practice... >> yet it's a practice we rely on for our current implementation of >> Hadoop2 support >> (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven >> slide 80). >> >> What this means is that even if we go through the work of publishing >> binary artifacts compiled against Hadoop2, neither our Hadoop1 >> binaries or our Hadoop2 binaries will be able to transitively resolve >> any dependencies defined in profiles. This has significant >> implications to user code that depends on Accumulo Maven artifacts. >> Every user will essentially have to explicitly add Hadoop dependencies >> for every Accumulo artifact that has dependencies on Hadoop, either >> because we directly or transitively depend on Hadoop (they'll have to >> peek into the profiles in our POMs and copy/paste the profile into >> their project). This becomes more complicated when we consider how >> users will try to use things like Instamo. >> >> There are workarounds, but none of them are really pleasant. >> >> 1. The best way to support both major Hadoop APIs is to have separate >> modules with separate dependencies directly in the POM. This is a fair >> amount of work, and in my opinion, would be too disruptive for 1.5.0. >> This solution also gets us separate binaries for separate supported >> versions, which is useful. >> >> 2. A second option, and the preferred one I think for 1.5.0, is to put >> a Hadoop2 patch in the branch's contrib directory >> (branches/1.5/contrib) that patches the POM files to support building >> against Hadoop2. (Acknowledgement to Keith for suggesting this >> solution.) >> >> 3. A third option is to fork Accumulo, and maintain two separate >> builds (a more traditional technique). This adds merging nightmare for >> features/patches, but gets around some reflection hacks that we may >> have been motivated to do in the past. I'm not a fan of this option, >> particularly because I don't want to replicate the fork nightmare that >> has been the history of early Hadoop itself. >> >> 4. The last option is to do nothing and to continue to build with the >> separate profiles as we are, and make users discover and specify >> transitive dependencies entirely on their own. I think this is the >> worst option, as it essentially amounts to "ignore the problem". >> >> At the very least, it does not seem reasonable to complete >> ACCUMULO-1402 for 1.5.0, given the complexity of this issue. >> >> Thoughts? Discussion? Vote on option? >> >> -- >> Christopher L Tubbs II >> http://gravatar.com/ctubbsii >> > > > > -- > Sean Busbey > Solutions Architect > Cloudera, Inc. > Phone: MAN-VS-BEARD
Re: Hadoop 2 compatibility issues
I tend to agree with Sean, John, and Benson. Option 4 works for now, and until we can define something that works better (e.g. runtime compatibility with both hadoop 1 and 2 using reflection and crazy class loaders) we should not delay the release. Good docs are always helpful where engineering is less than ideal (egad, I hope I didn't just volunteer!). Adam On Tue, May 14, 2013 at 5:16 PM, Benson Margulies wrote: > CXF does (4) for the various competing JAX-WS implementations. > > The different options are API-compatible, and the profiles just switch > the deps around. > > There would be slightly more Maven correctness in marking the deps > optional, forcing each user to pick one explicitly. > > However, (4) with good doc on what to put in the POM is really not a > cause for shame. Maven is weak in this area, and it's all tradeoffs. > > > > On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: > > I'm an advocate of option 4. You say that it's ignoring the problem, > > whereas I think it's waiting until we have the time to solve the problem > > correctly. Your reasoning for this is for standardizing for maven > > conventions, but the other options, while more 'correct' from a maven > > standpoint or a larger headache for our user base and ourselves. In > either > > case, we're going to be breaking some sort of convention, and while it's > > not good, we should be doing the one that's less bad for US. The > important > > thing here, now, is that the poms work and we should go with the method > > that leaves the work minimal for our end users to utilize them. > > > > I do agree that 1. is the correct option in the long run. More > > specifically, I think it boils down to having a single module > compatibility > > layer, which is how hbase deals with this issue. But like you said, we > > don't have the time to engineer a proper solution. So let sleeping dogs > lie > > and we can revamp the whole system for 1.5.1 or 1.6.0 when we have the > > cycles to do it right. > > > > > > On Tue, May 14, 2013 at 4:40 PM, Christopher > wrote: > > > >> So, I've run into a problem with ACCUMULO-1402 that requires a larger > >> discussion about how Accumulo 1.5.0 should support Hadoop2. > >> > >> The problem is basically that profiles should not contain > >> dependencies, because profiles don't get activated transitively. A > >> slide deck by the Maven developers point this out as a bad practice... > >> yet it's a practice we rely on for our current implementation of > >> Hadoop2 support > >> (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > >> slide 80). > >> > >> What this means is that even if we go through the work of publishing > >> binary artifacts compiled against Hadoop2, neither our Hadoop1 > >> binaries or our Hadoop2 binaries will be able to transitively resolve > >> any dependencies defined in profiles. This has significant > >> implications to user code that depends on Accumulo Maven artifacts. > >> Every user will essentially have to explicitly add Hadoop dependencies > >> for every Accumulo artifact that has dependencies on Hadoop, either > >> because we directly or transitively depend on Hadoop (they'll have to > >> peek into the profiles in our POMs and copy/paste the profile into > >> their project). This becomes more complicated when we consider how > >> users will try to use things like Instamo. > >> > >> There are workarounds, but none of them are really pleasant. > >> > >> 1. The best way to support both major Hadoop APIs is to have separate > >> modules with separate dependencies directly in the POM. This is a fair > >> amount of work, and in my opinion, would be too disruptive for 1.5.0. > >> This solution also gets us separate binaries for separate supported > >> versions, which is useful. > >> > >> 2. A second option, and the preferred one I think for 1.5.0, is to put > >> a Hadoop2 patch in the branch's contrib directory > >> (branches/1.5/contrib) that patches the POM files to support building > >> against Hadoop2. (Acknowledgement to Keith for suggesting this > >> solution.) > >> > >> 3. A third option is to fork Accumulo, and maintain two separate > >> builds (a more traditional technique). This adds merging nightmare for > >> features/patches, but gets around some reflection hacks that we may > >> have been motivated to do in the past. I'm not a fan of this option, > >> particularly because I don't want to replicate the fork nightmare that > >> has been the history of early Hadoop itself. > >> > >> 4. The last option is to do nothing and to continue to build with the > >> separate profiles as we are, and make users discover and specify > >> transitive dependencies entirely on their own. I think this is the > >> worst option, as it essentially amounts to "ignore the problem". > >> > >> At the very least, it does not seem reasonable to complete > >> ACCUMULO-1402 for 1.5.0, given the complexity of this issue. > >> > >> Thoughts? Discussion? Vote on option? > >> > >> -- >
Re: Hadoop 2 compatibility issues
CXF does (4) for the various competing JAX-WS implementations. The different options are API-compatible, and the profiles just switch the deps around. There would be slightly more Maven correctness in marking the deps optional, forcing each user to pick one explicitly. However, (4) with good doc on what to put in the POM is really not a cause for shame. Maven is weak in this area, and it's all tradeoffs. On Tue, May 14, 2013 at 4:56 PM, John Vines wrote: > I'm an advocate of option 4. You say that it's ignoring the problem, > whereas I think it's waiting until we have the time to solve the problem > correctly. Your reasoning for this is for standardizing for maven > conventions, but the other options, while more 'correct' from a maven > standpoint or a larger headache for our user base and ourselves. In either > case, we're going to be breaking some sort of convention, and while it's > not good, we should be doing the one that's less bad for US. The important > thing here, now, is that the poms work and we should go with the method > that leaves the work minimal for our end users to utilize them. > > I do agree that 1. is the correct option in the long run. More > specifically, I think it boils down to having a single module compatibility > layer, which is how hbase deals with this issue. But like you said, we > don't have the time to engineer a proper solution. So let sleeping dogs lie > and we can revamp the whole system for 1.5.1 or 1.6.0 when we have the > cycles to do it right. > > > On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: > >> So, I've run into a problem with ACCUMULO-1402 that requires a larger >> discussion about how Accumulo 1.5.0 should support Hadoop2. >> >> The problem is basically that profiles should not contain >> dependencies, because profiles don't get activated transitively. A >> slide deck by the Maven developers point this out as a bad practice... >> yet it's a practice we rely on for our current implementation of >> Hadoop2 support >> (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven >> slide 80). >> >> What this means is that even if we go through the work of publishing >> binary artifacts compiled against Hadoop2, neither our Hadoop1 >> binaries or our Hadoop2 binaries will be able to transitively resolve >> any dependencies defined in profiles. This has significant >> implications to user code that depends on Accumulo Maven artifacts. >> Every user will essentially have to explicitly add Hadoop dependencies >> for every Accumulo artifact that has dependencies on Hadoop, either >> because we directly or transitively depend on Hadoop (they'll have to >> peek into the profiles in our POMs and copy/paste the profile into >> their project). This becomes more complicated when we consider how >> users will try to use things like Instamo. >> >> There are workarounds, but none of them are really pleasant. >> >> 1. The best way to support both major Hadoop APIs is to have separate >> modules with separate dependencies directly in the POM. This is a fair >> amount of work, and in my opinion, would be too disruptive for 1.5.0. >> This solution also gets us separate binaries for separate supported >> versions, which is useful. >> >> 2. A second option, and the preferred one I think for 1.5.0, is to put >> a Hadoop2 patch in the branch's contrib directory >> (branches/1.5/contrib) that patches the POM files to support building >> against Hadoop2. (Acknowledgement to Keith for suggesting this >> solution.) >> >> 3. A third option is to fork Accumulo, and maintain two separate >> builds (a more traditional technique). This adds merging nightmare for >> features/patches, but gets around some reflection hacks that we may >> have been motivated to do in the past. I'm not a fan of this option, >> particularly because I don't want to replicate the fork nightmare that >> has been the history of early Hadoop itself. >> >> 4. The last option is to do nothing and to continue to build with the >> separate profiles as we are, and make users discover and specify >> transitive dependencies entirely on their own. I think this is the >> worst option, as it essentially amounts to "ignore the problem". >> >> At the very least, it does not seem reasonable to complete >> ACCUMULO-1402 for 1.5.0, given the complexity of this issue. >> >> Thoughts? Discussion? Vote on option? >> >> -- >> Christopher L Tubbs II >> http://gravatar.com/ctubbsii >>
Re: Hadoop 2 compatibility issues
I'm an advocate of option 4. You say that it's ignoring the problem, whereas I think it's waiting until we have the time to solve the problem correctly. Your reasoning for this is for standardizing for maven conventions, but the other options, while more 'correct' from a maven standpoint or a larger headache for our user base and ourselves. In either case, we're going to be breaking some sort of convention, and while it's not good, we should be doing the one that's less bad for US. The important thing here, now, is that the poms work and we should go with the method that leaves the work minimal for our end users to utilize them. I do agree that 1. is the correct option in the long run. More specifically, I think it boils down to having a single module compatibility layer, which is how hbase deals with this issue. But like you said, we don't have the time to engineer a proper solution. So let sleeping dogs lie and we can revamp the whole system for 1.5.1 or 1.6.0 when we have the cycles to do it right. On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: > So, I've run into a problem with ACCUMULO-1402 that requires a larger > discussion about how Accumulo 1.5.0 should support Hadoop2. > > The problem is basically that profiles should not contain > dependencies, because profiles don't get activated transitively. A > slide deck by the Maven developers point this out as a bad practice... > yet it's a practice we rely on for our current implementation of > Hadoop2 support > (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > slide 80). > > What this means is that even if we go through the work of publishing > binary artifacts compiled against Hadoop2, neither our Hadoop1 > binaries or our Hadoop2 binaries will be able to transitively resolve > any dependencies defined in profiles. This has significant > implications to user code that depends on Accumulo Maven artifacts. > Every user will essentially have to explicitly add Hadoop dependencies > for every Accumulo artifact that has dependencies on Hadoop, either > because we directly or transitively depend on Hadoop (they'll have to > peek into the profiles in our POMs and copy/paste the profile into > their project). This becomes more complicated when we consider how > users will try to use things like Instamo. > > There are workarounds, but none of them are really pleasant. > > 1. The best way to support both major Hadoop APIs is to have separate > modules with separate dependencies directly in the POM. This is a fair > amount of work, and in my opinion, would be too disruptive for 1.5.0. > This solution also gets us separate binaries for separate supported > versions, which is useful. > > 2. A second option, and the preferred one I think for 1.5.0, is to put > a Hadoop2 patch in the branch's contrib directory > (branches/1.5/contrib) that patches the POM files to support building > against Hadoop2. (Acknowledgement to Keith for suggesting this > solution.) > > 3. A third option is to fork Accumulo, and maintain two separate > builds (a more traditional technique). This adds merging nightmare for > features/patches, but gets around some reflection hacks that we may > have been motivated to do in the past. I'm not a fan of this option, > particularly because I don't want to replicate the fork nightmare that > has been the history of early Hadoop itself. > > 4. The last option is to do nothing and to continue to build with the > separate profiles as we are, and make users discover and specify > transitive dependencies entirely on their own. I think this is the > worst option, as it essentially amounts to "ignore the problem". > > At the very least, it does not seem reasonable to complete > ACCUMULO-1402 for 1.5.0, given the complexity of this issue. > > Thoughts? Discussion? Vote on option? > > -- > Christopher L Tubbs II > http://gravatar.com/ctubbsii >
Re: Hadoop 2 compatibility issues
If a user is referencing any of the Hadoop classes, aren't they supposed to add a dependency on the appropriate Hadoop artifact anyways? FWIW, option 4 is what Avro does. Their discussion: https://issues.apache.org/jira/browse/AVRO-1170 On Tue, May 14, 2013 at 4:40 PM, Christopher wrote: > So, I've run into a problem with ACCUMULO-1402 that requires a larger > discussion about how Accumulo 1.5.0 should support Hadoop2. > > The problem is basically that profiles should not contain > dependencies, because profiles don't get activated transitively. A > slide deck by the Maven developers point this out as a bad practice... > yet it's a practice we rely on for our current implementation of > Hadoop2 support > (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven > slide 80). > > What this means is that even if we go through the work of publishing > binary artifacts compiled against Hadoop2, neither our Hadoop1 > binaries or our Hadoop2 binaries will be able to transitively resolve > any dependencies defined in profiles. This has significant > implications to user code that depends on Accumulo Maven artifacts. > Every user will essentially have to explicitly add Hadoop dependencies > for every Accumulo artifact that has dependencies on Hadoop, either > because we directly or transitively depend on Hadoop (they'll have to > peek into the profiles in our POMs and copy/paste the profile into > their project). This becomes more complicated when we consider how > users will try to use things like Instamo. > > There are workarounds, but none of them are really pleasant. > > 1. The best way to support both major Hadoop APIs is to have separate > modules with separate dependencies directly in the POM. This is a fair > amount of work, and in my opinion, would be too disruptive for 1.5.0. > This solution also gets us separate binaries for separate supported > versions, which is useful. > > 2. A second option, and the preferred one I think for 1.5.0, is to put > a Hadoop2 patch in the branch's contrib directory > (branches/1.5/contrib) that patches the POM files to support building > against Hadoop2. (Acknowledgement to Keith for suggesting this > solution.) > > 3. A third option is to fork Accumulo, and maintain two separate > builds (a more traditional technique). This adds merging nightmare for > features/patches, but gets around some reflection hacks that we may > have been motivated to do in the past. I'm not a fan of this option, > particularly because I don't want to replicate the fork nightmare that > has been the history of early Hadoop itself. > > 4. The last option is to do nothing and to continue to build with the > separate profiles as we are, and make users discover and specify > transitive dependencies entirely on their own. I think this is the > worst option, as it essentially amounts to "ignore the problem". > > At the very least, it does not seem reasonable to complete > ACCUMULO-1402 for 1.5.0, given the complexity of this issue. > > Thoughts? Discussion? Vote on option? > > -- > Christopher L Tubbs II > http://gravatar.com/ctubbsii > -- Sean Busbey Solutions Architect Cloudera, Inc. Phone: MAN-VS-BEARD
Hadoop 2 compatibility issues
So, I've run into a problem with ACCUMULO-1402 that requires a larger discussion about how Accumulo 1.5.0 should support Hadoop2. The problem is basically that profiles should not contain dependencies, because profiles don't get activated transitively. A slide deck by the Maven developers point this out as a bad practice... yet it's a practice we rely on for our current implementation of Hadoop2 support (http://www.slideshare.net/aheritier/geneva-jug-30th-march-2010-maven slide 80). What this means is that even if we go through the work of publishing binary artifacts compiled against Hadoop2, neither our Hadoop1 binaries or our Hadoop2 binaries will be able to transitively resolve any dependencies defined in profiles. This has significant implications to user code that depends on Accumulo Maven artifacts. Every user will essentially have to explicitly add Hadoop dependencies for every Accumulo artifact that has dependencies on Hadoop, either because we directly or transitively depend on Hadoop (they'll have to peek into the profiles in our POMs and copy/paste the profile into their project). This becomes more complicated when we consider how users will try to use things like Instamo. There are workarounds, but none of them are really pleasant. 1. The best way to support both major Hadoop APIs is to have separate modules with separate dependencies directly in the POM. This is a fair amount of work, and in my opinion, would be too disruptive for 1.5.0. This solution also gets us separate binaries for separate supported versions, which is useful. 2. A second option, and the preferred one I think for 1.5.0, is to put a Hadoop2 patch in the branch's contrib directory (branches/1.5/contrib) that patches the POM files to support building against Hadoop2. (Acknowledgement to Keith for suggesting this solution.) 3. A third option is to fork Accumulo, and maintain two separate builds (a more traditional technique). This adds merging nightmare for features/patches, but gets around some reflection hacks that we may have been motivated to do in the past. I'm not a fan of this option, particularly because I don't want to replicate the fork nightmare that has been the history of early Hadoop itself. 4. The last option is to do nothing and to continue to build with the separate profiles as we are, and make users discover and specify transitive dependencies entirely on their own. I think this is the worst option, as it essentially amounts to "ignore the problem". At the very least, it does not seem reasonable to complete ACCUMULO-1402 for 1.5.0, given the complexity of this issue. Thoughts? Discussion? Vote on option? -- Christopher L Tubbs II http://gravatar.com/ctubbsii