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https://issues.apache.org/jira/browse/HIVE-13249?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15281880#comment-15281880
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Eugene Koifman commented on HIVE-13249:
---------------------------------------
what I meant is
{noformat}
public OpenTxnsResponse openTxns(OpenTxnRequest rqst) throws MetaException {
384 if (openTxnsCounter == null) {
synchronzied(TxnHandler.class) {
385 try {
if (openTxnsCounter == null) {
386 startHouseKeeperService(conf,
Class.forName("org.apache.hadoop.hive.ql.txn.AcidOpenTxnsCounterService"));
}
387 } catch (Exception e) {
388 throw new MetaException(e.getMessage());
389 }
}
390 }
{noformat}
http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html
One more thing:
startHouseKeeperService() catches Exception and logs but when openTxns() calls
startHouseKeeperService() it catches and rethrows.
Seems contradictory. Did you want to fail all txns if this service is not
available or make best effort?
> Hard upper bound on number of open transactions
> -----------------------------------------------
>
> Key: HIVE-13249
> URL: https://issues.apache.org/jira/browse/HIVE-13249
> Project: Hive
> Issue Type: Improvement
> Components: Transactions
> Affects Versions: 2.0.0
> Reporter: Wei Zheng
> Assignee: Wei Zheng
> Attachments: HIVE-13249.1.patch, HIVE-13249.2.patch,
> HIVE-13249.3.patch, HIVE-13249.4.patch, HIVE-13249.5.patch,
> HIVE-13249.6.patch, HIVE-13249.7.patch, HIVE-13249.8.patch, HIVE-13249.9.patch
>
>
> We need to have a safeguard by adding an upper bound for open transactions to
> avoid huge number of open-transaction requests, usually due to improper
> configuration of clients such as Storm.
> Once that limit is reached, clients will start failing.
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