Cool. Thanks.

On Fri, Mar 25, 2016 at 12:02 PM, Sudheesh Katkam <[email protected]>
wrote:

> @Jacques, let me check the performance test [1] results from the past with
> epoll disabled (or we have to re-run).
>
> @Hanifi, With higher concurrency in performance testing, queries failed
> with this error:
>
> java.io.IOException: syscall:read(...)() failed: Connection reset by peer
>
> This is a known issue [2] with the version of Netty that Drill uses. I
> don’t think there is a specific ticket, but a search [3] shows a few
> relevant tickets.
>
> Thank you,
> Sudheesh
>
> [1] https://github.com/mapr/drill-perf-test-framework <
> https://github.com/mapr/drill-perf-test-framework>
> [2] https://github.com/netty/netty/issues/3539 <
> https://github.com/netty/netty/issues/3539>[3]
> https://issues.apache.org/jira/browse/DRILL-3119?jql=project%20%3D%20DRILL%20AND%20text%20~%20%22syscall%3Aread%22
> <
> https://issues.apache.org/jira/browse/DRILL-3119?jql=project%20=%20DRILL%20AND%20text%20~%20%22syscall:read%22
> >
>
> > On Mar 25, 2016, at 11:44 AM, Hanifi Gunes <[email protected]> wrote:
> >
> > I am wondering what the issue and its manifestation was back then. Do we
> > have any JIRAs created for this before?
> >
> >
> > Thanks.
> > -Hanifi
> >
> > On Fri, Mar 25, 2016 at 9:57 AM, Jacques Nadeau <[email protected]>
> wrote:
> >
> >> Hey All,
> >>
> >> If I recall correctly, many months ago Sudheesh discovered that we were
> >> having instability in RPC connections in some situations due to bugs in
> the
> >> epoll implementation that are fixed in a later version of Netty
> (~4.0.31?).
> >> At the time, we shelved switching Netty because it also changed the
> memory
> >> caching behavior (same thread to all thread) which seemed like a high
> risk
> >> change. I thought that as part of this we decided the safest change was
> to
> >> disable epoll RPC in our distribution. However, reviewing drill-env, it
> >> doesn't look like we do this. See here [1].
> >>
> >> Thoughts?
> >>
> >> [1]
> >>
> >>
> https://github.com/apache/drill/blob/master/distribution/src/resources/drill-env.sh#L19
> >> --
> >> Jacques Nadeau
> >> CTO and Co-Founder, Dremio
> >>
>
>

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