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https://issues.apache.org/jira/browse/IGNITE-9447?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16602430#comment-16602430
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Pavel Kuznetsov edited comment on IGNITE-9447 at 9/3/18 8:06 PM:
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We decided not to use distributed mutex, just lookup thhought the topology
history
was (Author: pkouznet):
We decided not to use distributed mutex, just lookup into the topology history
> Benchmarks hangs intemittently due to distributed race condition.
> -----------------------------------------------------------------
>
> Key: IGNITE-9447
> URL: https://issues.apache.org/jira/browse/IGNITE-9447
> Project: Ignite
> Issue Type: Bug
> Components: sql
> Reporter: Pavel Kuznetsov
> Assignee: Pavel Kuznetsov
> Priority: Minor
>
> If we run more than one yardstick driver, benchmark hangs intermittently.
> We've got yardstick's base driver class
> org.apache.ignite.yardstick.IgniteAbstractBenchmark it has logic to wait all
> the nodes in the cluster.
> {noformat}
> final CountDownLatch nodesStartedLatch = new CountDownLatch(1);
> ignite().events().localListen(new IgnitePredicate<Event>() {
> @Override public boolean apply(Event gridEvt) {
> if (nodesStarted())
> nodesStartedLatch.countDown();
> return true;
> }
> }, EVT_NODE_JOINED);
> if (!nodesStarted()) {
> println(cfg, "Waiting for " + (args.nodes() - 1) + " nodes to
> start...");
> nodesStartedLatch.await();
> }
> {noformat}
> This code is executed on every driver node.
> If we want to close local ignite instance just after cluster is ready
> (containing expected number of nodes), sometimes we'll have dead lock:
> 1) cluster contains N-1 nodes, all nodes are waiting for the Nth node.
> 2) Nth node is connected, cluster receives message, waitForNodes code of Nth
> node is not executed.
> 3) N-1 nodes got this message and stop waiting.
> 4) N-1 thinks that cluster is ready and call ignite.close() on their local
> instances
> 5) Nth node starts waiting for cluster to contain number of nodes, but N-1 of
> them closed their instances
> 6) Nth node is waiting infinitely.
> We can avoid this problem if we use distributed CountDownLatch
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