[jira] [Created] (HIVE-16180) LLAP: Native memory leak in EncodedReader

["Prasanth Jayachandran (JIRA)" <ji...@apache.org>]

Prasanth Jayachandran created HIVE-16180:
--------------------------------------------

             Summary: LLAP: Native memory leak in EncodedReader
                 Key: HIVE-16180
                 URL: https://issues.apache.org/jira/browse/HIVE-16180
             Project: Hive
          Issue Type: Bug
          Components: llap
    Affects Versions: 2.2.0
            Reporter: Prasanth Jayachandran
            Assignee: Prasanth Jayachandran
            Priority: Critical


Observed this in internal test run. There is a native memory leak in Orc EncodedReaderImpl that can cause YARN pmem monitor to kill the container running the daemon. Direct byte buffers are null'ed out which is not guaranteed to be cleaned until next Full GC. To show this take issue, attaching a small test program that allocations 3x256MB direct byte buffers. First buffer is null'ed out but still native memory is used. Second buffer user Cleaner to clean up native allocation. Third buffer is also null'ed but this time invoking a System.gc() which cleans up all native memory. Output from the test program is below

{code}
Allocating 3x256MB direct memory..
Native memory used: 786432000
Native memory used after data1=null: 786432000
Native memory used after data2.clean(): 524288000
Native memory used after data3=null: 524288000
Native memory used without gc: 524288000
Native memory used after gc: 0
{code}

Longer term improvements/solutions:
1) Use DirectBufferPool from hadoop or netty's https://netty.io/4.0/api/io/netty/buffer/PooledByteBufAllocator.html as direct byte buffer allocations are expensive (System.gc() + 100ms thread sleep).
2) Use HADOOP-12760 for proper cleaner invocation in JDK8 and JDK9




--
This message was sent by Atlassian JIRA
(v6.3.15#6346)