drill-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Sudheesh Katkam <skat...@maprtech.com>
Subject Re: epoll disconnections?
Date Fri, 25 Mar 2016 19:02:12 GMT
@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 <hgunes@maprtech.com> 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 <jacques@dremio.com> 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
>> 


Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message