[ http://issues.apache.org/jira/browse/HADOOP-637?page=all ]
Doug Cutting updated HADOOP-637: -------------------------------- Status: Resolved (was: Patch Available) Resolution: Fixed I just committed this. Thanks, Raghu! > ipc.Server has memory leak -- serious issue for namenode server > --------------------------------------------------------------- > > Key: HADOOP-637 > URL: http://issues.apache.org/jira/browse/HADOOP-637 > Project: Hadoop > Issue Type: Bug > Components: ipc > Affects Versions: 0.7.1 > Reporter: Christian Kunz > Assigned To: Raghu Angadi > Attachments: directbuffers.patch > > > In my environment (running a lot of batch processes each of which reads, > creates, and deletes a lof of files in dfs) the namenode server can run out > of memory rather quickly (in a few hours on a 150 node cluster). The netbeans > profiler shows an increasing number of direct byte buffers not garbage > collected. The documentation on java.nio.ByteBuffer indicates that their > allocation might (and obviously does) happen outside the normal gc-collected > heap, and, therefore, it is required that direct byte buffers should only be > used for long-lived objects. > ipc.Server seems to use a 4KB direct byte buffer for every connection, but, > worse, for every RPC call. If I replace the latter ones with non-direct byte > buffers, the memory footprint of the namenode server increases only slowly, > but even then it is just a matter of time (since I started it 24 hours ago, > it leaked by about 300-400MB). If the performance increase by using direct > buffers is a requirement, I would suggest to use a static pool. > Although my environment abuses the namenode server in unusual manner, I would > imagine that the memory footprint of the namenode server creeps up slowly > everywhere -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira