> On 7 Oct 2015, at 07:29, Masatake Iwasaki <iwasak...@oss.nttdata.co.jp> wrote: > > Thanks for clear summary, Tsuyoshi. > > I read some related past discussions. > > https://wiki.apache.org/hadoop/MovingToJdk7and8 > http://search-hadoop.com/m/uOzYtGSiCs1acRnh > http://search-hadoop.com/m/uOzYthdWJqpGdSZ1 > > Though there seems to be no consensus about when to drop java 7 support yet, > it would not be 2.8 for which the preparation is already started. > If the works for making source compatible with java 8 does not result in > dropping java 7 support, it would be nice and easy to backport to branch-2. > > > > we need to upgrade grizzly to 2.2.16 to use > > jersey-test-framework-grizzly2. I’d like to discuss which version we > > will target this change. Can we do this in branch-2? > > At lease, the newest grizzly, jersey and asm seems to support java 7 too > and HADOOP-11993 may work in branch-2. >
Certainly for trunk, I'm +1 for making the leap. For branch 2, how backwards compatible/incompatible is the change? I think we'd have to test it downstream; I can use slider & spark as test builds locally —YARN apps are the failure points. Someone else would have to try HBase. In that world, we could think of having a short-lived branch-2-java-8 branch, which cherry picks the grizzly changes from trunk, and which we can then use for that downstream testing > > Masatake Iwasaki > > > On 10/6/15 09:35, Tsuyoshi Ozawa wrote: > > Hi commiters and users of Hadoop stack, > > > > I’ll share the current status of JDK-8 support here. We can take a > > two-step approach to support JDK-8 - runtime-level support and > > source-level support. > > > > About runtime-level support, I’ve tested Hadoop stack with JDK-8 e.g. > > MapReduce, Spark, Tez, Flink on YARN and HDFS for a few months. As > > long as I tested, it works well completely since JDK-8 doesn’t have > > any incompatibility at binary level. We can say Hadoop has supported > > JDK8 runtime already. Do you have any concern about this? I’ve not > > tested with HBase yet. I need help of HBase community. I think only > > problem about runtime is HADOOP-11364, default value of > > colntainer-killer of YARN. After fixing the issue, we can declare the > > support of JDK on Hadoop Wiki to make it clear for users. > > https://wiki.apache.org/hadoop/HadoopJavaVersions > > > > About source-level, however, we have one big problem - upgrading > > dependency of asm and cglib. We need to upgrade all libraries which > > depends on asm to support new byte code introduced in JDK8[1]. The > > dependencies which uses asm are jersey-server for compile and provide > > scope, and cglib for test scope(I checked it with mvn dependency:tree > > command). HADOOP-9613 is addressing the problem. > > > > One complex problem I’ve faced is Jersey depends on grizzly - to > > upgrade jersey to 1.19, which supports JDK8, > > we need to upgrade grizzly to 2.2.16 to use > > jersey-test-framework-grizzly2. I’d like to discuss which version we > > will target this change. Can we do this in branch-2? Should we take > > care of HADOOP-11656 and HADOOP-11993 at the same time? I’d also > > confirm whether HADOOP-11993 means to remove Jersey, which depends on > > asm, or not. I think we can collaborate with Yetus community here. > > > > Also, another simple problem is that source code cannot be compiled > > because javadoc format or variable identifier are illegal(e.g. > > HADOOP-12457, HADOOP-11875). I think this can be solved > > straightforwardly. > > > > Please share any concern I’ve missed. The opinions of users are also > > welcome :-) > > I'd like to go forward this step by step to make Hadoop user friendly. > > > > Thanks Steve, Sean, Allen, Robert, Brahma, Akira, Larry, Allen, Andrew > > Purtell, Tsz-wo Sze, Sethen and other guys for having lots works about > > JDK-8. > > > > Best regards, > > - Tsuyoshi > > > > [1] http://product.hubspot.com/blog/upgrading-to-java-8-at-scale > > [2] http://ispras.linuxbase.org/index.php/Java_API_Compliance_Checker > >
