[jira] [Created] (HBASE-12431) Use of getColumnLatestCell(byte[], int, int, byte[], int, int) is Not Thread Safe

["Jonathan Jarvis (JIRA)" <ji...@apache.org>]

Jonathan Jarvis created HBASE-12431:
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             Summary: Use of getColumnLatestCell(byte[], int, int, byte[], int, int) is Not Thread Safe
                 Key: HBASE-12431
                 URL: https://issues.apache.org/jira/browse/HBASE-12431
             Project: HBase
          Issue Type: Bug
          Components: Client
    Affects Versions: 0.98.1
            Reporter: Jonathan Jarvis


Result declares that it is NOT THREAD SAFE at the top of the source code, but one would assume that refers to many different threads accessing the same Result object. I've run into an issue when I have several different threads accessing their own Result object that runs into an issue because of use of common static member variable.

I noticed the problem when I switched from:

getColumnLatestCell(byte[], byte[]) to
getColumnLatestCell(byte[], int, int, byte[], int, int)

These methods call different binarySearch methods, the latter invoking:

protected int  binarySearch(final Cell [] kvs,
309      final byte [] family, final int foffset, final int flength,
310      final byte [] qualifier, final int qoffset, final int qlength) {

This method utilizes a private static member variable called "buffer"

If more than one thread is utilizing "buffer" you'll see unpredictable behavior unless you synchronize(Result.class) {}.

If buffer is to remain a static variable, I would recommend changing it to a ThreadLocal<byte[]> instead.




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