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Hudson commented on HIVE-3098: ------------------------------ Integrated in Hive-0.9.1-SNAPSHOT-h0.21 #137 (See [https://builds.apache.org/job/Hive-0.9.1-SNAPSHOT-h0.21/137/]) HIVE-3098 : Memory leak from large number of FileSystem instances in FileSystem.CACHE (Mithun Radhakrishnan via Ashutosh Chauhan) (Revision 1384541) Result = SUCCESS hashutosh : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1384541 Files : * /hive/branches/branch-0.9/metastore/src/java/org/apache/hadoop/hive/metastore/TUGIBasedProcessor.java * /hive/branches/branch-0.9/shims/src/0.20/java/org/apache/hadoop/hive/shims/Hadoop20Shims.java * /hive/branches/branch-0.9/shims/src/common-secure/java/org/apache/hadoop/hive/shims/HadoopShimsSecure.java * /hive/branches/branch-0.9/shims/src/common-secure/java/org/apache/hadoop/hive/thrift/HadoopThriftAuthBridge20S.java * /hive/branches/branch-0.9/shims/src/common/java/org/apache/hadoop/hive/shims/HadoopShims.java > Memory leak from large number of FileSystem instances in FileSystem.CACHE > ------------------------------------------------------------------------- > > Key: HIVE-3098 > URL: https://issues.apache.org/jira/browse/HIVE-3098 > Project: Hive > Issue Type: Bug > Components: Shims > Affects Versions: 0.9.0 > Environment: Running with Hadoop 20.205.0.3+ / 1.0.x with security > turned on. > Reporter: Mithun Radhakrishnan > Assignee: Mithun Radhakrishnan > Fix For: 0.10.0, 0.9.1 > > Attachments: Hive-3098_(FS_closeAllForUGI()).patch, hive-3098.patch, > Hive_3098.patch > > > The problem manifested from stress-testing HCatalog 0.4.1 (as part of testing > the Oracle backend). > The HCatalog server ran out of memory (-Xmx2048m) when pounded by 60-threads, > in under 24 hours. The heap-dump indicates that hadoop::FileSystem.CACHE had > 1000000 instances of FileSystem, whose combined retained-mem consumed the > entire heap. > It boiled down to hadoop::UserGroupInformation::equals() being implemented > such that the "Subject" member is compared for equality ("=="), and not > equivalence (".equals()"). This causes equivalent UGI instances to compare as > unequal, and causes a new FileSystem instance to be created and cached. > The UGI.equals() is so implemented, incidentally, as a fix for yet another > problem (HADOOP-6670); so it is unlikely that that implementation can be > modified. > The solution for this is to check for UGI equivalence in HCatalog (i.e. in > the Hive metastore), using an cache for UGI instances in the shims. > I have a patch to fix this. I'll upload it shortly. I just ran an overnight > test to confirm that the memory-leak has been arrested. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira