[jira] [Created] (HBASE-16992) The usage of mutation from CP is weird.

["ChiaPing Tsai (JIRA)" <ji...@apache.org>]

ChiaPing Tsai created HBASE-16992:
-------------------------------------

             Summary: The usage of mutation from CP is weird.
                 Key: HBASE-16992
                 URL: https://issues.apache.org/jira/browse/HBASE-16992
             Project: HBase
          Issue Type: Bug
            Reporter: ChiaPing Tsai


{code:title=HRegion.java|borderStyle=solid}
Mutation cpMutation = cpMutations[j];
Map<byte[], List<Cell>> cpFamilyMap = cpMutation.getFamilyCellMap();
checkAndPrepareMutation(cpMutation, replay, cpFamilyMap, now);
 // Acquire row locks. If not, the whole batch will fail.
acquiredRowLocks.add(getRowLockInternal(cpMutation.getRow(), true));
if (cpMutation.getDurability() == Durability.SKIP_WAL) {
  recordMutationWithoutWal(cpFamilyMap);
}
// Returned mutations from coprocessor correspond to the Mutation at index i. We can
 // directly add the cells from those mutations to the familyMaps of this mutation.
mergeFamilyMaps(familyMaps[i], cpFamilyMap); // will get added to the memstore later
{code}


1. Does the returned mutation from coprocessor have the same row as the corresponded mutation? If so, the acquiredRowLocks() can be saved. If not, the corresponded mutation may maintain the cells with different row due to mergeFamilyMaps().
2. Is returned mutation's durability useful? If so, we should deal with the different durabilities before merge. If not, the recordMutationWithoutWal can be saved. 
3. If both the returned mutation and corresponded mutation have Durability.SKIP_WAL, the recordMutationWithoutWal() may record the duplicate cells due to mergeFamilyMaps().

Any comment? Thanks.



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