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 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> >> <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/ <http://datastax.com/>>
