[jira] [Commented] (HIVE-15373) Transaction management isn't thread-safe

[Alexander Kolbasov (JIRA)]

    [ 
https://issues.apache.org/jira/browse/HIVE-15373?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15727175#comment-15727175
 ] 

Alexander Kolbasov commented on HIVE-15373:
-------------------------------------------

Here is the code for openTransaction():

{code}
  public boolean openTransaction() {
    openTrasactionCalls++;
    if (openTrasactionCalls == 1) {
      currentTransaction = pm.currentTransaction();
      currentTransaction.begin();
      transactionStatus = TXN_STATUS.OPEN;
    } else {
      // openTransactionCalls > 1 means this is an interior transaction
      // We should already have a transaction created that is active.
      if ((currentTransaction == null) || (!currentTransaction.isActive())){
        throw new RuntimeException("openTransaction called in an interior"
            + " transaction scope, but currentTransaction is not active.");
      }
    }

    boolean result = currentTransaction.isActive();
    debugLog("Open transaction: count = " + openTrasactionCalls + ", isActive = 
" + result);
    return result;
  }
{code}

So variables 

*  openTrasactionCalls (obviously misspelled)
* currentTransaction
* transactionStatus 

are not protected by anything and in case of concurrent access may 
accessed/modified concurrently causing all sorts of inconsistent behavior.


> Transaction management isn't thread-safe
> ----------------------------------------
>
>                 Key: HIVE-15373
>                 URL: https://issues.apache.org/jira/browse/HIVE-15373
>             Project: Hive
>          Issue Type: Bug
>          Components: Hive
>            Reporter: Alexander Kolbasov
>
> ObjectStore.java has several important calls which are not thread-safe:
> * openTransaction()
> * commitTransaction()
> * rollbackTransaction()
> These should be made thread-safe.



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