Hi developers, I'd like to discuss how to make an advance towards dependency management in Apache Hadoop trunk code since there has been lots work about updating dependencies in parallel. Summarizing recent works and activities as follows:
0) Currently, we have merged minimum update dependencies for making Hadoop JDK-8 compatible(compilable and runnable on JDK-8). 1) After that, some people suggest that we should update the other dependencies on trunk(e.g. protobuf, netty, jackthon etc.). 2) In parallel, Sangjin and Sean are working on classpath isolation: HADOOP-13070, HADOOP-11804 and HADOOP-11656. Main problems we try to solve in the activities above is as follows: * 1) tries to solve dependency hell between user-level jar and system(Hadoop)-level jar. * 2) tries to solve updating old libraries. IIUC, 1) and 2) looks not related, but it's related in fact. 2) tries to separate class loader between client-side dependencies and server-side dependencies in Hadoop, so we can the change policy of updating libraries after doing 2). We can also decide which libraries can be shaded after 2). Hence, IMHO, a straight way we should go to is doing 2 at first. After that, we can update both client-side and server-side dependencies based on new policy(maybe we should discuss what kind of incompatibility is acceptable, and the others are not). Thoughts? Thanks, - Tsuyoshi --------------------------------------------------------------------- To unsubscribe, e-mail: mapreduce-dev-unsubscr...@hadoop.apache.org For additional commands, e-mail: mapreduce-dev-h...@hadoop.apache.org
