Hi Augustine, Java 11 is not supported even in the latest version in Apache Hadoop. I hope Apache Hadoop 3.3.0 will support Java 11 (only runtime support) but 3.3.0 is not released yet. (Our company (Yahoo! JAPAN) builds trunk with OpenJDK 8 and run HDFS dev cluster with OpenJDK 11 successfully.)
CDH 6 backports some patches from trunk and that's why it supports openjdk11. > Which jdks's/jvm's are supported Now Apache Hadoop is using OpenJDK for build environment, and that's why OpenJDK should be supported in the community. https://github.com/apache/hadoop/blob/rel/release-3.2.1/dev-support/docker/Dockerfile#L92 Other jdk's/jvm's should work well, but I think they are not officially supported. I'll update the wiki to include that information. Regards, Akira On Wed, Dec 4, 2019 at 3:36 AM Augustine Calvino <acalvi...@gmail.com> wrote: > I want to know what java versions are compatible with the latest hadoop. > The most that the documentation > <https://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-common/ClusterSetup.html#Prerequisites> > says > is to check the wiki > <https://cwiki.apache.org/confluence/display/HADOOP2/HadoopJavaVersions>, > which is obviously out of date since it only is listing java 6 and 7. That > wiki has a link to another wiki page > <https://cwiki.apache.org/confluence/display/HADOOP/Hadoop+Java+Versions>, > which is more helpful, as it actually lists the compatible versions of > java. However, it doesn't say which jdk's/jvm's are supported (Oracle vs > OpenJDK, vs AdoptOpenJDK, or hotspot vs open-j9). Also, that page says that > hadoop 3 is only compatible with java 8, but Cloudera's CDH 6, which uses > <https://docs.cloudera.com/documentation/enterprise/6/release-notes/topics/rg_cdh_63_packaging.html#cdh_632_packaging> > hadoop > 3, apparently supports > <https://docs.cloudera.com/documentation/enterprise/6/release-notes/topics/rg_java_requirements.html#concept_ugf_4sg_5gb> > openjdk11. > > We would really like to use java 11 with our new hadoop builds due to the > improved garbage collection, and would also prefer to use non-oracle jdk > builds, but the messaging about what is supported seems sparse and > sometimes contradictory. Any clarification would be appreciated. > > Thanks! > > - Augustine >
