Re: [discuss] Modernization of Cassandra build system
Hey Benedict, My replies in line According to some recordings from DataStax there is a plan to support in Cassandra multiple kinds of store - document, graph so it won’t get easier with the time but rather harder - ask yourself do you really want to mess all these things together? Well, these certainly won't live in the same repository, so I wouldn't worry about that That’s good. That’s very good cause it will force separation. If you will do that please consider using other build system to don’t repeat mistakes which are present now in main Cassandra build. As I briefly counted in my ealier mail there was 116 issues related to artifacts published by build process. That does sound like a lot of bugs. How many actual maintenance releases were necessary, did you happen to also count? This is something that could be raised at the new retrospective that Ariel has begun, to see if there's anything that can be done to reduce their incidence and risk. There have been 159 minor releases of cassandra (git tag —list | egrep rc | egrep beta | wc -l). I did not track exactly what is correnation of the bug ration. These 116 vs 159 are just numbers. From my understanding there is 116 unecessary issues which could be avoided. You can read these numbers in two different ways - every second minor release was fixing maven artifacts OR every second release was broken due the maven artifacts. Seems you preffer first one while users usualy observes second. however it gives real boost when it comes to community donations, tool development, or even debugging You're conflating the task of upgrading the build system with modularisation, which is a bad idea if you want to make progress on either one, since they're each a different and difficult discussion, even if they relate. I do that cause this is typical chicken vs egg problem. One thing can not be done without another it’s just question which one is fist to follow. Code modularization/package separation without strict bounds is hard to follow. However nothing prevents doing this in reverse mode - by solving code issues first and then introducing new build tool. It’s up to cassandra developers to decide. On the topic of the build system: if you can justify why you think Maven has a significant chance of reducing our bug burden here, a case can perhaps be made, and I will defer to the members of this list with more experience of our build system for that in depth discussion. At the moment, it seems to be taken as a given this would occur, but I don't yet see a clear reason that we should expect this to occur. You see - I don’t have to justify Maven. I have proposed you a help with it. I also gave you couple of reasons why Ant is not first sort of tools these days. I don’t feel myself responsible for doing any advocating for Maven itself. It’s up to you what you choose. The major thing, major problem which modern tools are doing for you is build time classpath management (both compile test) and separate javac executions for both of these. Take what you preffer - gradle, sbt, leiningen. Anything which does things from previous sentence. Do your own evaluation. Take what work for you, not only for me. On the topic of modularisation: Like I said previously, everyone on this list is sympathetic to that goal, I think. However the practical reality is likely to be too confounding. But that doesn't mean it is absolutely a losing battle, if you can demonstrate a sufficiently painless and worthwhile transition. I don't quite get you at this point. From one side you suppose everyone is for taking such step, from another one you ask for proofs. In case of code relocation there are always multiple ways. Cause of what you have currently forces solution of multiple problems. You can start on any of it (ie. circular dependencies I did mention in earlier conversation doesn’t require changing a tool). In place where you stay at this moment there will be no such thing as painless transition. As said ealier - it will be only harder over time. Given example from my life. We do use Cassandra. We do have plenty of mid level integration tests which are verifying end to end functionality. Starting from frontend or messaging layer up to data persistence. Now each of our tests even if it consist a low amount of data hits IO on multiple levels - starting from socket ending on disk. We do not test in such cases consistency levels as it’s assumed to be tested by cassandra itself - we are ensuring that incoming data passes storage interface and can be retrieved back via same interface. With what cassandra is now we can not make our tests running fast. People are prisoners of cassandra-unit cause embedding cassandra is impossible, even if it’s written using portable language. It has too many inner and outer dependencies. On other hand we have for example ActiveMQ which has lots of options. Even with all of these it might be embedded
Re: [discuss] Modernization of Cassandra build system
every second minor release was fixing maven artifacts OR every second release was broken due the maven artifacts Well, it's also possible just one release had 116 build artefact problems? Obviously that's the absurd extreme end, but the reason I was asking if you had any idea, since you'd done the counting. I don’t feel myself responsible for doing any advocating for Maven itself. It’s up to you what you choose. This is a community process, and I'm trying (and apparently failing) to help you understand at least how *I* understand it to work, and the problems I see with what you're proposing. The silence on the list suggests there is significant inertia and no other strong advocates for this change. This could be for myriad reasons, from people simply not caring, to thinking there are roughly equal pros and cons, to also just hoping the conversation will go away because they're against it. Without advocacy, the inertia is not overcome, and since you're the only person so far to express a desire for this change, it is unfortunately up to you to convince us. I, and I'm sure the rest of the community, are very appreciative of the offer of your time. We really are. Unfortunately that isn't enough to warrant utilising it, but we *are* open to discussion and advocacy on the topic. The crux of the problem is that Cassandra has a lot of important work being done to it, work that I personally perceive (and suspect others do also) as more important than the admitted inadequacy of our modularisation and, perhaps, our build system (I plead ignorance here). This work is currently surpassing the labour we have to address it. If this upheaval hinders that work, that is bad, and that is what I mean when I say warrants - is the upheaval small enough, or the yield really great (modularisation doesn't always pan out, so we may not even get a good result, but still have the significant pain)? I don't want to give you the impression I am either a gatekeeper or shooting down your proposal. I'm just attempting to explain my perception of the view of the existing contributors. On Mon, Apr 13, 2015 at 9:31 PM, Łukasz Dywicki l...@code-house.org wrote: Hey Benedict, My replies in line According to some recordings from DataStax there is a plan to support in Cassandra multiple kinds of store - document, graph so it won’t get easier with the time but rather harder - ask yourself do you really want to mess all these things together? Well, these certainly won't live in the same repository, so I wouldn't worry about that That’s good. That’s very good cause it will force separation. If you will do that please consider using other build system to don’t repeat mistakes which are present now in main Cassandra build. As I briefly counted in my ealier mail there was 116 issues related to artifacts published by build process. That does sound like a lot of bugs. How many actual maintenance releases were necessary, did you happen to also count? This is something that could be raised at the new retrospective that Ariel has begun, to see if there's anything that can be done to reduce their incidence and risk. There have been 159 minor releases of cassandra (git tag —list | egrep rc | egrep beta | wc -l). I did not track exactly what is correnation of the bug ration. These 116 vs 159 are just numbers. From my understanding there is 116 unecessary issues which could be avoided. You can read these numbers in two different ways - every second minor release was fixing maven artifacts OR every second release was broken due the maven artifacts. Seems you preffer first one while users usualy observes second. however it gives real boost when it comes to community donations, tool development, or even debugging You're conflating the task of upgrading the build system with modularisation, which is a bad idea if you want to make progress on either one, since they're each a different and difficult discussion, even if they relate. I do that cause this is typical chicken vs egg problem. One thing can not be done without another it’s just question which one is fist to follow. Code modularization/package separation without strict bounds is hard to follow. However nothing prevents doing this in reverse mode - by solving code issues first and then introducing new build tool. It’s up to cassandra developers to decide. On the topic of the build system: if you can justify why you think Maven has a significant chance of reducing our bug burden here, a case can perhaps be made, and I will defer to the members of this list with more experience of our build system for that in depth discussion. At the moment, it seems to be taken as a given this would occur, but I don't yet see a clear reason that we should expect this to occur. You see - I don’t have to justify Maven. I have proposed you a help with it. I also gave you couple of reasons why Ant is not first sort of tools these
Re: [discuss] Modernization of Cassandra build system
According to some recordings from DataStax there is a plan to support in Cassandra multiple kinds of store - document, graph so it won’t get easier with the time but rather harder - ask yourself do you really want to mess all these things together? Well, these certainly won't live in the same repository, so I wouldn't worry about that As I briefly counted in my ealier mail there was 116 issues related to artifacts published by build process. That does sound like a lot of bugs. How many actual maintenance releases were necessary, did you happen to also count? This is something that could be raised at the new retrospective that Ariel has begun, to see if there's anything that can be done to reduce their incidence and risk. however it gives real boost when it comes to community donations, tool development, or even debugging You're conflating the task of upgrading the build system with modularisation, which is a bad idea if you want to make progress on either one, since they're each a different and difficult discussion, even if they relate. On the topic of the build system: if you can justify why you think Maven has a significant chance of reducing our bug burden here, a case can perhaps be made, and I will defer to the members of this list with more experience of our build system for that in depth discussion. At the moment, it seems to be taken as a given this would occur, but I don't yet see a clear reason that we should expect this to occur. On the topic of modularisation: Like I said previously, everyone on this list is sympathetic to that goal, I think. However the practical reality is likely to be too confounding. But that doesn't mean it is absolutely a losing battle, if you can demonstrate a sufficiently painless and worthwhile transition. On Sat, Apr 11, 2015 at 11:12 AM, Łukasz Dywicki l...@code-house.org wrote: Sorry for not coming back to topic for long time. You are right that what Cassandra project have currently - does work and keeping package scoping discipline in such big development community as Cassandra is clearly impossible without tool support (if you insist to keep ant please try to separate javac tasks for logical parts in current build to verify that). I clearly pointed out that it doesn’t work in reliable way causing troubles with artifacts uploaded to maven central. As I briefly counted in my ealier mail there was 116 issues related to artifacts published by build process. It is a lot and these changes requires another mainanance releases to fix for example one or another bytecode level dependency causing NoClassDefErrors with invalid artifacts. According to some recordings from DataStax there is a plan to support in Cassandra multiple kinds of store - document, graph so it won’t get easier with the time but rather harder - ask yourself do you really want to mess all these things together? Starting from 2.x Cassandra supports triggers but writing even a simplest trigger which will drop a log message or publish UDP packet requires entire cassandra and all it’s dependencies to be present during development. Fact that everything sits in one big ant build.xml is caused by troubles generated by ant itself to support multiple build modules, placeholders and so on, not because it’s handsome to do such. Modernization of build and internal dependencies is not something which brings huge benefit in first run cause now your frontend is CQL, however it gives real boost when it comes to community donations, tool development, or even debugging. Sadly keeping current Ant build is silent agreement to keep mess internally and rickety architecture of project. Ant was already legacy tool when Cassandra has been launched. The longer you will stay with it the more troubles you will get with it over time. Kind regards, Lukasz Wiadomość napisana przez Robert Stupp sn...@snazy.de w dniu 2 kwi 2015, o godz. 14:51: TL;DR - Benedict is right. IMO Maven is a nice, straight-forward tool if you know what you’re doing and start on a _new_ project. But Maven easily becomes a pita if you want to do something that’s not supported out-of-the-box. I bet that Maven would just not work for C* source tree with all the little nice features that C*’s build.xml offers (just look at the scripted stuff in build.xml). Eventually gradle would be an option; I proposed to switch to gradle several months ago. Same story (although gradle is better than Maven ;) ). But… you need to know that build.xml is not just used to build the code and artifacts. It is also used in CI, ccm, cstar-perf and a some other custom systems that exist and just work. So - if we would exchange ant with something else, it would force a lot of effort to change several tools and systems. And there must be a guarantee that everything works like it did before. Regarding IDEs: i’m using IDEA every day and it works like a charm with C*. Eclipse is ”supported natively” by
Re: [discuss] Modernization of Cassandra build system
Sorry for not coming back to topic for long time. You are right that what Cassandra project have currently - does work and keeping package scoping discipline in such big development community as Cassandra is clearly impossible without tool support (if you insist to keep ant please try to separate javac tasks for logical parts in current build to verify that). I clearly pointed out that it doesn’t work in reliable way causing troubles with artifacts uploaded to maven central. As I briefly counted in my ealier mail there was 116 issues related to artifacts published by build process. It is a lot and these changes requires another mainanance releases to fix for example one or another bytecode level dependency causing NoClassDefErrors with invalid artifacts. According to some recordings from DataStax there is a plan to support in Cassandra multiple kinds of store - document, graph so it won’t get easier with the time but rather harder - ask yourself do you really want to mess all these things together? Starting from 2.x Cassandra supports triggers but writing even a simplest trigger which will drop a log message or publish UDP packet requires entire cassandra and all it’s dependencies to be present during development. Fact that everything sits in one big ant build.xml is caused by troubles generated by ant itself to support multiple build modules, placeholders and so on, not because it’s handsome to do such. Modernization of build and internal dependencies is not something which brings huge benefit in first run cause now your frontend is CQL, however it gives real boost when it comes to community donations, tool development, or even debugging. Sadly keeping current Ant build is silent agreement to keep mess internally and rickety architecture of project. Ant was already legacy tool when Cassandra has been launched. The longer you will stay with it the more troubles you will get with it over time. Kind regards, Lukasz Wiadomość napisana przez Robert Stupp sn...@snazy.de w dniu 2 kwi 2015, o godz. 14:51: TL;DR - Benedict is right. IMO Maven is a nice, straight-forward tool if you know what you’re doing and start on a _new_ project. But Maven easily becomes a pita if you want to do something that’s not supported out-of-the-box. I bet that Maven would just not work for C* source tree with all the little nice features that C*’s build.xml offers (just look at the scripted stuff in build.xml). Eventually gradle would be an option; I proposed to switch to gradle several months ago. Same story (although gradle is better than Maven ;) ). But… you need to know that build.xml is not just used to build the code and artifacts. It is also used in CI, ccm, cstar-perf and a some other custom systems that exist and just work. So - if we would exchange ant with something else, it would force a lot of effort to change several tools and systems. And there must be a guarantee that everything works like it did before. Regarding IDEs: i’m using IDEA every day and it works like a charm with C*. Eclipse is ”supported natively” by ”ant generate-eclipse-files”. TBH I don’t know NetBeans. As Benedict pointed out, the code has improved and still improves a lot - in structure, in inline-doc, in nomenclature and whatever else. As soon as we can get rid of Thrift in the tree, there’s another big opportunity to cleanup more stuff. TBH I don’t think that (beside the tools) there would be a need to generate multiple artifacts for C* daemon - you can do ”separation of concerns” (via packages) even with discipline and then measure it. IMO The only artifact worth to extract out of C* tree, and useful for a (limited) set of 3rd party code, is something like ”cassandra-jmx-interfaces.jar” Robert Am 02.04.2015 um 11:30 schrieb Benedict Elliott Smith belliottsm...@datastax.com: There are three distinct problems you raise: code structure, documentation, and build system. The build system, as far as I can tell, is a matter of personal preference. I personally dislike the few interactions I've had with maven, but gratefully my interactions with build system innards have been fairly limited. I mostly just use them. Unless a concrete and significant benefit is delivered by maven, though, it just doesn't seem worth the upheaval to me. If you can make the argument that it actually improves the project in a way that justifies the upheaval, it will certainly be considered, but so far no justification has been made. The documentation problem is common to many projects, though: out of codebase documentation gets stale very rapidly. When we say to read the code we mean read the code and its inline documentation - the quality of this documentation has itself generally been substandard, but has been improving significantly over the past year or so, and we are endeavouring to improve with every change. In the meantime, there are videos from a
Re: [discuss] Modernization of Cassandra build system
There are three distinct problems you raise: code structure, documentation, and build system. The build system, as far as I can tell, is a matter of personal preference. I personally dislike the few interactions I've had with maven, but gratefully my interactions with build system innards have been fairly limited. I mostly just use them. Unless a concrete and significant benefit is delivered by maven, though, it just doesn't seem worth the upheaval to me. If you can make the argument that it actually improves the project in a way that justifies the upheaval, it will certainly be considered, but so far no justification has been made. The documentation problem is common to many projects, though: out of codebase documentation gets stale very rapidly. When we say to read the code we mean read the code and its inline documentation - the quality of this documentation has itself generally been substandard, but has been improving significantly over the past year or so, and we are endeavouring to improve with every change. In the meantime, there are videos from a recent bootcamp we've run for both internal and external contributors http://www.datastax.com/dev/blog/deep-into-cassandra-internals. The code structure would be great to modularise, but the reality is that it is not currently modular. There are no good clear dividing lines for much of the project. The problem with refactoring the entire codebase to create separate projects is that it is a significant undertaking that makes maintenance of the project across versions significantly more costly. This create a net drag on all productivity in the project. Such a major change requires strong consensus, and strong evidence justifying it. So the question is: would this create more new work than it loses? The evidence isn't there that it would. It might, but I personally guess that it would not, judging by the results of our other attempts to drive up contributions to the project. Perhaps we can have a wider dialogue about the endeavour, though, and see if a consensus can in fact be built. On Thu, Apr 2, 2015 at 9:31 AM, Pierre Devops pierredev...@gmail.com wrote: Hi all, Not a cassandra contributor here, but I'm working on the cassandra sources too. This big cassandra source root caused me trouble too, firstly it was not easy to import in an IDE, try to import cassandra sources in netbeans, it's a headcache. It would be great if we had more small modules/projects in separate POM. It will be more easier to work on small part of the project, and as a consequences, I'm sure you will have more external contribution to this project. I know cassandra devs are used to ant build model, but it's like a thread I opened about updated and more complete documentation about sstable structures. I got answer that it was not needed to understand how to use Cassandra, and the only way to learn about that is to rtfcode. Because people working on cassandra already know how sstable structure are, it's not needed to provide up to date documentation. So it will take me a very long time to read and understand all the serialization code in cassandra to understand the sttable structure before I can work on the code. Up to date documentation about internals would have gave me the knowledge I need to contribute much quicker. Here we have the same problem, we have a complex non modular build system, and core cassandra dev are used to it, so it's not needed to make something more flexible, even if it could facilite external contribution. 2015-03-31 23:42 GMT+02:00 Benedict Elliott Smith belliottsm...@datastax.com: I think the problem is everyone currently contributing is comfortable with ant, and as much as it is imperfect, it isn't clear maven is going to be better. Having the requisite maven functionality linked under the hood doesn't seem particularly preferable to the inverse. The status quo has the bonus of zero upheaval for the project and its contributors, though, so it would have to be a very clear win to justify the change in my opinion. On Tue, Mar 31, 2015 at 10:24 PM, Łukasz Dywicki l...@code-house.org wrote: Hey Tyler, Thank you very much for coming back. I already lost faith that I will get reply. :-) I am fine with code relocations. Moving constants into one place where they cause no circular dependencies is cool, I’m all for doing such thing. Currently Cassandra uses ant for doing some of maven functionalities (such deploying POM.xml into repositories with dependency information), it uses also maven type of artifact repositories. This can be easily flipped. Maven can call ant tasks for these parts which can not be made with existing maven plugins. Here is simplest example: http://docs.codehaus.org/display/MAVENUSER/Antrun+Plugin http://docs.codehaus.org/display/MAVENUSER/Antrun+Plugin - you can see ant task definition embedded in maven pom.xml. Most of
Re: [discuss] Modernization of Cassandra build system
TL;DR - Benedict is right. IMO Maven is a nice, straight-forward tool if you know what you’re doing and start on a _new_ project. But Maven easily becomes a pita if you want to do something that’s not supported out-of-the-box. I bet that Maven would just not work for C* source tree with all the little nice features that C*’s build.xml offers (just look at the scripted stuff in build.xml). Eventually gradle would be an option; I proposed to switch to gradle several months ago. Same story (although gradle is better than Maven ;) ). But… you need to know that build.xml is not just used to build the code and artifacts. It is also used in CI, ccm, cstar-perf and a some other custom systems that exist and just work. So - if we would exchange ant with something else, it would force a lot of effort to change several tools and systems. And there must be a guarantee that everything works like it did before. Regarding IDEs: i’m using IDEA every day and it works like a charm with C*. Eclipse is ”supported natively” by ”ant generate-eclipse-files”. TBH I don’t know NetBeans. As Benedict pointed out, the code has improved and still improves a lot - in structure, in inline-doc, in nomenclature and whatever else. As soon as we can get rid of Thrift in the tree, there’s another big opportunity to cleanup more stuff. TBH I don’t think that (beside the tools) there would be a need to generate multiple artifacts for C* daemon - you can do ”separation of concerns” (via packages) even with discipline and then measure it. IMO The only artifact worth to extract out of C* tree, and useful for a (limited) set of 3rd party code, is something like ”cassandra-jmx-interfaces.jar” Robert Am 02.04.2015 um 11:30 schrieb Benedict Elliott Smith belliottsm...@datastax.com: There are three distinct problems you raise: code structure, documentation, and build system. The build system, as far as I can tell, is a matter of personal preference. I personally dislike the few interactions I've had with maven, but gratefully my interactions with build system innards have been fairly limited. I mostly just use them. Unless a concrete and significant benefit is delivered by maven, though, it just doesn't seem worth the upheaval to me. If you can make the argument that it actually improves the project in a way that justifies the upheaval, it will certainly be considered, but so far no justification has been made. The documentation problem is common to many projects, though: out of codebase documentation gets stale very rapidly. When we say to read the code we mean read the code and its inline documentation - the quality of this documentation has itself generally been substandard, but has been improving significantly over the past year or so, and we are endeavouring to improve with every change. In the meantime, there are videos from a recent bootcamp we've run for both internal and external contributors http://www.datastax.com/dev/blog/deep-into-cassandra-internals. The code structure would be great to modularise, but the reality is that it is not currently modular. There are no good clear dividing lines for much of the project. The problem with refactoring the entire codebase to create separate projects is that it is a significant undertaking that makes maintenance of the project across versions significantly more costly. This create a net drag on all productivity in the project. Such a major change requires strong consensus, and strong evidence justifying it. So the question is: would this create more new work than it loses? The evidence isn't there that it would. It might, but I personally guess that it would not, judging by the results of our other attempts to drive up contributions to the project. Perhaps we can have a wider dialogue about the endeavour, though, and see if a consensus can in fact be built. On Thu, Apr 2, 2015 at 9:31 AM, Pierre Devops pierredev...@gmail.com wrote: Hi all, Not a cassandra contributor here, but I'm working on the cassandra sources too. This big cassandra source root caused me trouble too, firstly it was not easy to import in an IDE, try to import cassandra sources in netbeans, it's a headcache. It would be great if we had more small modules/projects in separate POM. It will be more easier to work on small part of the project, and as a consequences, I'm sure you will have more external contribution to this project. I know cassandra devs are used to ant build model, but it's like a thread I opened about updated and more complete documentation about sstable structures. I got answer that it was not needed to understand how to use Cassandra, and the only way to learn about that is to rtfcode. Because people working on cassandra already know how sstable structure are, it's not needed to provide up to date documentation. So it will take me a very long time to read and understand all the serialization code in cassandra to
Re: [discuss] Modernization of Cassandra build system
Hi Łukasz, I'm not very familiar with the build system, but I'll try to respond. The Serializer dependencies on org.apache.cassandra.transport are almost certainly uses of Server.CURRENT_VERSION and Server.VERSION_3. These are constants that represent the native protocol version in use, which affects how certain types are serialized. These constants could easily be moved. The o.a.c.marshal dependency in MapSerializer is on AbstractType, but could easily be replaced with java.util.Comparator. In any case, I'm not necessarily opposed to improving the build system to make these errors more apparent. Would your proposal still allow us to build with ant (and just change the way those artifacts are built)? On Tue, Mar 24, 2015 at 7:58 PM, Łukasz Dywicki l...@code-house.org wrote: Dear cassandra commiters and development process followers, I would like to bring an important topic off build process of cassandra. I am an external user from community point of view, however I been walking around various projects close to cassandra over past year or even more. What is worrying me a lot is how cassandra is publishing artifacts and how many problems are reported due that. First of all - I want to note that I am not born enemy of Ant itself. I never used it. I am also aware of problems with custom builds made with Maven, however I don’t really want to discuss any particular replacement, yet I want to note that Cassandra JIRA project contains about 116 issues related somehow to maven (http://bit.ly/1GRoXl5 http://bit.ly/1GRoXl5, project=CASSANDRA, text ~ maven). Depends on the point of view it might be a lot or a little. By simple statistics it is around 21 issues a year or almost 2 issues a month, many of them breaking maintanance/major releases from user point of view. From other hand it’s not bad considering how project is being built. Current structure has a very big disadvantage - ONE source root for multiple artifacts published in maven repositories and copying classes to jar AFTER they are compiled. Obviously ant copy task doesn’t follow import statements and does not include dependant classes. For example just by making test relocations and extraction of clientutil jar on master branch into separate source root I have found a bug where ListSerializer depends on org.apache.cassandra.transpor package. More over clientutil (MapSerializer) does depends on org.apache.cassandra.db.marshal package leading to the fact that it can not be used without cassandra-all present at classpath. Luckily for cassandra CQL as a new interface reduces thrift and clientutil usage reducing amount of issues reported around these, however this just hides a real problem in previous paragraph. I have found a handy tool and made a graph of circular dependencies in cassandra-all.jar. Graph of results can found here: http://grab.by/FRnO http://grab.by/FRnO. As you can see this graph has multiple levels and solving it is not a simple task. I am afraid a current way of building and packaging cassandra can create huge hiccups when it will come to code rafactorings cause entire cassandra will become a house of cards. Restructuring project into smaller pieces is also beneficiary for community since solving bugs in smaller units is definitelly easier. At the end of this mail I would like to propose moving Cassandra build system forward, regardless of tool which will be choosen for it. Personally I can volunteer in maven related changes to extract cassandra-thrift, cassandra-clientutil and cassandra-all to make regular maven build. It might be seen as a switch from one big XML into couple smaller. :-) All this depends on Cassandra developers decission to devide source roots or not. Kind regards, Łukasz Dywicki — l...@code-house.org Twitter: ldywicki Blog: http://dywicki.pl Code-House - http://code-house.org -- Tyler Hobbs DataStax http://datastax.com/
Re: [discuss] Modernization of Cassandra build system
I think the problem is everyone currently contributing is comfortable with ant, and as much as it is imperfect, it isn't clear maven is going to be better. Having the requisite maven functionality linked under the hood doesn't seem particularly preferable to the inverse. The status quo has the bonus of zero upheaval for the project and its contributors, though, so it would have to be a very clear win to justify the change in my opinion. On Tue, Mar 31, 2015 at 10:24 PM, Łukasz Dywicki l...@code-house.org wrote: Hey Tyler, Thank you very much for coming back. I already lost faith that I will get reply. :-) I am fine with code relocations. Moving constants into one place where they cause no circular dependencies is cool, I’m all for doing such thing. Currently Cassandra uses ant for doing some of maven functionalities (such deploying POM.xml into repositories with dependency information), it uses also maven type of artifact repositories. This can be easily flipped. Maven can call ant tasks for these parts which can not be made with existing maven plugins. Here is simplest example: http://docs.codehaus.org/display/MAVENUSER/Antrun+Plugin http://docs.codehaus.org/display/MAVENUSER/Antrun+Plugin - you can see ant task definition embedded in maven pom.xml. Most of things can be made at this moment via maven plugins: apache-rat-plugin: http://mvnrepository.com/artifact/org.apache.rat/apache-rat-plugin/0.11 http://mvnrepository.com/artifact/org.apache.rat/apache-rat-plugin/0.11 maven-thrift-plugin: http://mvnrepository.com/artifact/org.apache.thrift.tools/maven-thrift-plugin/0.1.11 http://mvnrepository.com/artifact/org.apache.thrift.tools/maven-thrift-plugin/0.1.11 antlr4-maven-plugin: http://mvnrepository.com/artifact/org.antlr/antlr4-maven-plugin/4.5 http://mvnrepository.com/artifact/org.antlr/antlr4-maven-plugin/4.5 or antlr3-maven-plugin: http://mvnrepository.com/artifact/org.antlr/antlr3-maven-plugin/3.5.2 http://mvnrepository.com/artifact/org.antlr/antlr3-maven-plugin/3.5.2 maven-gpg-plugin: http://mvnrepository.com/artifact/org.apache.maven.plugins/maven-gpg-plugin/1.6 http://mvnrepository.com/artifact/org.apache.maven.plugins/maven-gpg-plugin/1.6 maven-cobertura-plugin: http://mojo.codehaus.org/cobertura-maven-plugin/ http://mojo.codehaus.org/cobertura-maven-plugin/ (but these days jacoco with java agent instrumentation perfoms better) .. and so on I already made some evaluation of impact and it is big. Code has to be separated into different source roots. It’s not easy even for keeping current artifact structure: cassandra-all, cassandra-thrift and clientutil (cause of cyclic dependencies). What I can do is prepare of these src roots with dependencies which are declared for them and push that to my cassandra fork so you will be able to verify that and continue with relocations if you will like new build. Creating new modules (source roots) with maven is simple so you could possibly extract more than these 3 predefined artifacts/package roots. Just let me know if you are interested. Kind regards, Lukasz Wiadomość napisana przez Tyler Hobbs ty...@datastax.com w dniu 31 mar 2015, o godz. 21:57: Hi Łukasz, I'm not very familiar with the build system, but I'll try to respond. The Serializer dependencies on org.apache.cassandra.transport are almost certainly uses of Server.CURRENT_VERSION and Server.VERSION_3. These are constants that represent the native protocol version in use, which affects how certain types are serialized. These constants could easily be moved. The o.a.c.marshal dependency in MapSerializer is on AbstractType, but could easily be replaced with java.util.Comparator. In any case, I'm not necessarily opposed to improving the build system to make these errors more apparent. Would your proposal still allow us to build with ant (and just change the way those artifacts are built)? On Tue, Mar 24, 2015 at 7:58 PM, Łukasz Dywicki l...@code-house.org mailto:l...@code-house.org wrote: Dear cassandra commiters and development process followers, I would like to bring an important topic off build process of cassandra. I am an external user from community point of view, however I been walking around various projects close to cassandra over past year or even more. What is worrying me a lot is how cassandra is publishing artifacts and how many problems are reported due that. First of all - I want to note that I am not born enemy of Ant itself. I never used it. I am also aware of problems with custom builds made with Maven, however I don’t really want to discuss any particular replacement, yet I want to note that Cassandra JIRA project contains about 116 issues related somehow to maven (http://bit.ly/1GRoXl5 http://bit.ly/1GRoXl5 http://bit.ly/1GRoXl5 http://bit.ly/1GRoXl5, project=CASSANDRA, text ~ maven). Depends on the point of view it might be a lot or a
Re: [discuss] Modernization of Cassandra build system
Hey Tyler, Thank you very much for coming back. I already lost faith that I will get reply. :-) I am fine with code relocations. Moving constants into one place where they cause no circular dependencies is cool, I’m all for doing such thing. Currently Cassandra uses ant for doing some of maven functionalities (such deploying POM.xml into repositories with dependency information), it uses also maven type of artifact repositories. This can be easily flipped. Maven can call ant tasks for these parts which can not be made with existing maven plugins. Here is simplest example: http://docs.codehaus.org/display/MAVENUSER/Antrun+Plugin http://docs.codehaus.org/display/MAVENUSER/Antrun+Plugin - you can see ant task definition embedded in maven pom.xml. Most of things can be made at this moment via maven plugins: apache-rat-plugin: http://mvnrepository.com/artifact/org.apache.rat/apache-rat-plugin/0.11 http://mvnrepository.com/artifact/org.apache.rat/apache-rat-plugin/0.11 maven-thrift-plugin: http://mvnrepository.com/artifact/org.apache.thrift.tools/maven-thrift-plugin/0.1.11 http://mvnrepository.com/artifact/org.apache.thrift.tools/maven-thrift-plugin/0.1.11 antlr4-maven-plugin: http://mvnrepository.com/artifact/org.antlr/antlr4-maven-plugin/4.5 http://mvnrepository.com/artifact/org.antlr/antlr4-maven-plugin/4.5 or antlr3-maven-plugin: http://mvnrepository.com/artifact/org.antlr/antlr3-maven-plugin/3.5.2 http://mvnrepository.com/artifact/org.antlr/antlr3-maven-plugin/3.5.2 maven-gpg-plugin: http://mvnrepository.com/artifact/org.apache.maven.plugins/maven-gpg-plugin/1.6 http://mvnrepository.com/artifact/org.apache.maven.plugins/maven-gpg-plugin/1.6 maven-cobertura-plugin: http://mojo.codehaus.org/cobertura-maven-plugin/ http://mojo.codehaus.org/cobertura-maven-plugin/ (but these days jacoco with java agent instrumentation perfoms better) .. and so on I already made some evaluation of impact and it is big. Code has to be separated into different source roots. It’s not easy even for keeping current artifact structure: cassandra-all, cassandra-thrift and clientutil (cause of cyclic dependencies). What I can do is prepare of these src roots with dependencies which are declared for them and push that to my cassandra fork so you will be able to verify that and continue with relocations if you will like new build. Creating new modules (source roots) with maven is simple so you could possibly extract more than these 3 predefined artifacts/package roots. Just let me know if you are interested. Kind regards, Lukasz Wiadomość napisana przez Tyler Hobbs ty...@datastax.com w dniu 31 mar 2015, o godz. 21:57: Hi Łukasz, I'm not very familiar with the build system, but I'll try to respond. The Serializer dependencies on org.apache.cassandra.transport are almost certainly uses of Server.CURRENT_VERSION and Server.VERSION_3. These are constants that represent the native protocol version in use, which affects how certain types are serialized. These constants could easily be moved. The o.a.c.marshal dependency in MapSerializer is on AbstractType, but could easily be replaced with java.util.Comparator. In any case, I'm not necessarily opposed to improving the build system to make these errors more apparent. Would your proposal still allow us to build with ant (and just change the way those artifacts are built)? On Tue, Mar 24, 2015 at 7:58 PM, Łukasz Dywicki l...@code-house.org mailto:l...@code-house.org wrote: Dear cassandra commiters and development process followers, I would like to bring an important topic off build process of cassandra. I am an external user from community point of view, however I been walking around various projects close to cassandra over past year or even more. What is worrying me a lot is how cassandra is publishing artifacts and how many problems are reported due that. First of all - I want to note that I am not born enemy of Ant itself. I never used it. I am also aware of problems with custom builds made with Maven, however I don’t really want to discuss any particular replacement, yet I want to note that Cassandra JIRA project contains about 116 issues related somehow to maven (http://bit.ly/1GRoXl5 http://bit.ly/1GRoXl5 http://bit.ly/1GRoXl5 http://bit.ly/1GRoXl5, project=CASSANDRA, text ~ maven). Depends on the point of view it might be a lot or a little. By simple statistics it is around 21 issues a year or almost 2 issues a month, many of them breaking maintanance/major releases from user point of view. From other hand it’s not bad considering how project is being built. Current structure has a very big disadvantage - ONE source root for multiple artifacts published in maven repositories and copying classes to jar AFTER they are compiled. Obviously ant copy task doesn’t follow import statements and does not include dependant classes. For example just by making test relocations and extraction of clientutil
[discuss] Modernization of Cassandra build system
Dear cassandra commiters and development process followers, I would like to bring an important topic off build process of cassandra. I am an external user from community point of view, however I been walking around various projects close to cassandra over past year or even more. What is worrying me a lot is how cassandra is publishing artifacts and how many problems are reported due that. First of all - I want to note that I am not born enemy of Ant itself. I never used it. I am also aware of problems with custom builds made with Maven, however I don’t really want to discuss any particular replacement, yet I want to note that Cassandra JIRA project contains about 116 issues related somehow to maven (http://bit.ly/1GRoXl5 http://bit.ly/1GRoXl5, project=CASSANDRA, text ~ maven). Depends on the point of view it might be a lot or a little. By simple statistics it is around 21 issues a year or almost 2 issues a month, many of them breaking maintanance/major releases from user point of view. From other hand it’s not bad considering how project is being built. Current structure has a very big disadvantage - ONE source root for multiple artifacts published in maven repositories and copying classes to jar AFTER they are compiled. Obviously ant copy task doesn’t follow import statements and does not include dependant classes. For example just by making test relocations and extraction of clientutil jar on master branch into separate source root I have found a bug where ListSerializer depends on org.apache.cassandra.transpor package. More over clientutil (MapSerializer) does depends on org.apache.cassandra.db.marshal package leading to the fact that it can not be used without cassandra-all present at classpath. Luckily for cassandra CQL as a new interface reduces thrift and clientutil usage reducing amount of issues reported around these, however this just hides a real problem in previous paragraph. I have found a handy tool and made a graph of circular dependencies in cassandra-all.jar. Graph of results can found here: http://grab.by/FRnO http://grab.by/FRnO. As you can see this graph has multiple levels and solving it is not a simple task. I am afraid a current way of building and packaging cassandra can create huge hiccups when it will come to code rafactorings cause entire cassandra will become a house of cards. Restructuring project into smaller pieces is also beneficiary for community since solving bugs in smaller units is definitelly easier. At the end of this mail I would like to propose moving Cassandra build system forward, regardless of tool which will be choosen for it. Personally I can volunteer in maven related changes to extract cassandra-thrift, cassandra-clientutil and cassandra-all to make regular maven build. It might be seen as a switch from one big XML into couple smaller. :-) All this depends on Cassandra developers decission to devide source roots or not. Kind regards, Łukasz Dywicki — l...@code-house.org Twitter: ldywicki Blog: http://dywicki.pl Code-House - http://code-house.org