I'm referring to the later case. Indeed migrating JDK7 for branch-2 is more difficult.
I think one reasonable approach is to put the hdfs / yarn clients into separate jars. The client-side jars can only use JDK6 APIs, so that downstream projects running on top of JDK6 continue to work. The HDFS/YARN/MR servers need to be run on top of JDK7, and we're free to use JDK7 APIs inside them. Given the fact that there're way more code in the server-side compared to the client-side, having the ability to use JDK7 in the server-side only might still be a win. The downside I can think of is that it might complicate the effort of publishing maven jars, but this should be an one-time issue. ~Haohui On Fri, Apr 4, 2014 at 2:37 PM, Alejandro Abdelnur <t...@cloudera.com>wrote: > Haohui, > > Is the idea to compile/test with JDK7 and recommend it for runtime and stop > there? Or to start using JDK7 API stuff as well? If the later is the case, > then backporting stuff to branch-2 may break and patches may have to be > refactored for JDK6. Given that branch-2 got GA status not so long ago, I > assume it will be active for a while. > > What are your thoughts on this regard? > > Thanks > > > On Fri, Apr 4, 2014 at 2:29 PM, Haohui Mai <h...@hortonworks.com> wrote: > > > Hi, > > > > There have been multiple discussions on deprecating supports of JDK6 and > > moving towards JDK7. It looks to me that the consensus is that now hadoop > > is ready to drop the support of JDK6 and to move towards JDK7. Based on > the > > consensus, I wonder whether it is a good time to start the migration. > > > > Here are my understandings of the current status: > > > > 1. There is no more public updates of JDK6 since Feb 2013. Users no > longer > > get fixes of security vulnerabilities through official public updates. > > 2. Hadoop core is stuck with out-of-date dependency unless moving towards > > JDK7. (see > > http://hadoop.6.n7.nabble.com/very-old-dependencies-td71486.html) > > The implementation can also benefit from it thanks to the new > > functionalities in JDK7. > > 3. The code is ready for JDK7. Cloudera and Hortonworks have successful > > stories of supporting Hadoop on JDK7. > > > > > > It seems that the real work of moving to JDK7 is minimal. We only need to > > (1) make sure the jenkins are running on top of JDK7, and (2) to update > the > > minimum required Java version from 6 to 7. Therefore I propose that let's > > move towards JDK7 in trunk in the short term. > > > > Your feedbacks are appreciated. > > > > Regards, > > Haohui > > > > -- > > CONFIDENTIALITY NOTICE > > NOTICE: This message is intended for the use of the individual or entity > to > > which it is addressed and may contain information that is confidential, > > privileged and exempt from disclosure under applicable law. If the reader > > of this message is not the intended recipient, you are hereby notified > that > > any printing, copying, dissemination, distribution, disclosure or > > forwarding of this communication is strictly prohibited. If you have > > received this communication in error, please contact the sender > immediately > > and delete it from your system. Thank You. > > > > > > -- > Alejandro > -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.
