<div dir="ltr">There is no guarantee that connections will be evenly distributed between IO threads. Once a client has connected the connection is tied to that IO thread, so it may be that you are just ending up with 2 connections on 4 threads.<div><br></div><div>Stuart</div><div><br></div><div><br><div><br></div></div></div><br><div class="gmail_quote"><div dir="ltr">On Wed, Jul 25, 2018 at 10:02 AM R. Matt Barnett <<a href="mailto:barnett@rice.edu">barnett@rice.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hello,<br>
<br>
I'm experiencing an Undertow performance issue I fail to understand. I <br>
am able to reproduce the issue with the code linked bellow. The problem <br>
is that on Red Hat (and not Windows) I'm unable to concurrently process <br>
more than 4 overlapping requests even with 8 configured IO Threads. <br>
For example, if I run the following program (1 file, 55 lines):<br>
<br>
<a href="https://gist.github.com/rmbarnett-rice/668db6b4e9f8f8da7093a3659b6ae2b5" rel="noreferrer" target="_blank">https://gist.github.com/rmbarnett-rice/668db6b4e9f8f8da7093a3659b6ae2b5</a><br>
<br>
... on Red Hat and then send requests to the server using Apache <br>
Benchmark...<br>
<br>
> ab -n 1000 -c 8 localhost:8080/<br>
<br>
I see the following output from the Undertow process:<br>
<br>
Server started on port 8080<br>
<br>
1<br>
2<br>
3<br>
4<br>
<br>
I believe this demonstrates that only 4 requests are ever processed in <br>
parallel. I would expect 8. In fact, when I run the same experiment on <br>
Windows I see the expected output of<br>
<br>
Server started on port 8080<br>
1<br>
2<br>
3<br>
4<br>
5<br>
6<br>
7<br>
8<br>
<br>
Any thoughts as to what might explain this behavior?<br>
<br>
Best,<br>
<br>
Matt<br>
<br>
_______________________________________________<br>
undertow-dev mailing list<br>
<a href="mailto:undertow-dev@lists.jboss.org" target="_blank">undertow-dev@lists.jboss.org</a><br>
<a href="https://lists.jboss.org/mailman/listinfo/undertow-dev" rel="noreferrer" target="_blank">https://lists.jboss.org/mailman/listinfo/undertow-dev</a></blockquote></div>