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<p class="MsoNormal"><span style="mso-fareast-language:EN-US">That looks like a good solution, but not having any Kotlin in our build yet I'm hesitant to use it.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">It's also not clear from the email chain exactly how you schedule an additional task when a request is accepted/queued, especially if you don't have Kotlin Extensions available.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">I came up with a higher-level solution:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">- add X-Received-Time header to request in forward proxy / load balancer<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">- add servlet filter to check header and sendError(503) if it exceeds the configured timeout (though in my case the client will never receive this)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">It seems like there's still a core bug of not reacting to the client-side close though.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">James<o:p></o:p></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> Stan Rosenberg <stan.rosenberg@acm.org>
<br>
<b>Sent:</b> 28 February 2020 19:18<br>
<b>To:</b> James Howe <jmh205@cam.ac.uk><br>
<b>Cc:</b> undertow-dev@lists.jboss.org<br>
<b>Subject:</b> Re: [undertow-dev] Worker queue timeout<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:12.0pt">On Thu, Feb 27, 2020 at 4:47 PM James Howe <</span><a href="mailto:jmh205@cam.ac.uk"><span style="font-size:12.0pt">jmh205@cam.ac.uk</span></a><span style="font-size:12.0pt">> wrote:<o:p></o:p></span></p>
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<p class="MsoNormal">Under load, when the worker threads are saturated, new requests will be queued.<br>
Is there a way to timeout these requests, so that it doesn't waste time serving them later when the client has already given up?<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">If I understand correctly, the same issue was discussed in this thread: <a href="https://lists.jboss.org/pipermail/undertow-dev/2018-July/002231.html" target="_blank">https://lists.jboss.org/pipermail/undertow-dev/2018-July/002231.html</a><o:p></o:p></p>
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<p class="MsoNormal">We ended up implementing custom logic based on CAS; here is the snippet in kotlin: <a href="https://gist.github.com/srosenberg/ed8d71d2f68379f909b1c4b8343807aa" target="_blank">https://gist.github.com/srosenberg/ed8d71d2f68379f909b1c4b8343807aa</a><o:p></o:p></p>
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<p class="MsoNormal">Thus, if a request takes longer than requestTimeoutMillis to service, the exchange is ended with StatusCodes.REQUEST_TIME_OUT<o:p></o:p></p>
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<p class="MsoNormal">The performance overhead of CAS was negligible.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Best,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">stan<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:12.0pt">P.S. Sorry for the duplicate; first attempt to post was rejected by list server because I used the wrong reply address.<o:p></o:p></span></p>
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