<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>I'm ok with that if it helps us get to the bottom of this once and for all. </div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">I wonder if it would be possible to enable the logging conditionally, so it only appears in CI? Maybe via a runtime call ("turn logging on now"). </div><div id="AppleMailSignature"><br>- Tony</div><div><br>On May 23, 2017, at 2:25 AM, Pushkar N Kulkarni <<a href="mailto:pushkar.nk@in.ibm.com">pushkar.nk@in.ibm.com</a>> wrote:<br><br></div><blockquote type="cite"><div><font face="Verdana,Arial,Helvetica,sans-serif" size="2"><div>Hi Tony, </div><div><br></div><div>In this context, would it be acceptable if we add (temporarily) some diagnostic prints to TestNSURLSession to log information only on failures? <br><font face="Verdana,Arial,Helvetica,sans-serif" size="2"><font><font><div class="socmaildefaultfont" dir="ltr"><div class="socmaildefaultfont" dir="ltr"><div class="socmaildefaultfont" dir="ltr"><div dir="ltr" style="font-style: normal;"><br><font face="Sans Serif, Verdana, Arial, Helvetica, sans-serif">Pushkar N Kulkarni,</font></div>
<div dir="ltr" style="font-style: normal;"><font face="Sans Serif, Verdana, Arial, Helvetica, sans-serif">IBM Runtimes</font></div><div dir="ltr" style="font-style: normal;"><font face="Sans Serif, Verdana, Arial, Helvetica, sans-serif"><br></font></div><div dir="ltr"><font face="serif, Times New Roman, Times, serif"><i>Simplicity is prerequisite for reliability - Edsger W. Dijkstra</i></font></div>
<div dir="ltr" style="font-style: normal; font-size: 10.5pt; font-family: Arial;"><br></div></div></div></div></font></font></font></div><br><br><font face="Default Sans Serif,Verdana,Arial,Helvetica,sans-serif" size="2" color="#000000"><font color="#990099">-----Pushkar N Kulkarni/India/IBM wrote: -----</font><div class="iNotesHistory" style="padding-left:5px;"><div style="padding-right:0px;padding-left:5px;border-left:solid black 2px;">To: <a href="mailto:swift-dev@swift.org" target="_blank">swift-dev@swift.org</a>, <a href="mailto:swift-corelibs-dev@swift.org" target="_blank">swift-corelibs-dev@swift.org</a><br>From: Pushkar N Kulkarni/India/IBM<br>Date: 05/19/2017 01:24AM<br>Subject: Debugging failures seen only in CI<br><br><font face="Verdana,Arial,Helvetica,sans-serif" size="2">Over the past few months, we've seen random and intermittent failures in the URLSession tests in TestFoundation in the CI builds running on Ubuntu 16.04. Surprisingly, these failures never occur on PR builds. We've tried to reproduce them locally (on matching Ubuntu levels) and fixed locally observed issues, assuming those were the issues that broke the CI. <br><font face="Verdana,Arial,Helvetica,sans-serif" size="2"><font><font><div class="socmaildefaultfont" dir="ltr"><div class="socmaildefaultfont" dir="ltr"><div class="socmaildefaultfont" dir="ltr"><div dir="ltr" style="font-style: normal;"><br></div><div dir="ltr" style="font-style: normal;">However, the tests continue to intermittently fail in the CI and we seemed to have reached a point where we simply aren't able to reproduce these failures locally - we tried 2/4/16CPU with 8G/16G memory running Ubuntu 16.04 on bare metal. Even if we are able to reproduce, as is in the case of a segfault, there's no way to ascertain that the local failures have the same causes (e.g backtrace for a segfault) as the ones in the CI. </div><div dir="ltr" style="font-style: normal;"><br></div><div dir="ltr" style="font-style: normal;">I have two questions in this context:</div><div dir="ltr" style="font-style: normal;">1. Is there a way to collect failure data from the CI environment - core dumps on a crash or thread stacks on a timeout (I don't think XCTest helps) ? </div><div dir="ltr" style="font-style: normal;">2. Is there a way to obtain more information about the environment - is it virtualised, # of CPU cores, memory size, CPU/memory available for each build, what's the load (CPU/memory utilisation)? </div><div dir="ltr" style="font-style: normal;"><br></div><div dir="ltr" style="font-style: normal;">In general, I'd be really helpful to have some suggestions about how to go about debugging failures that are being observed ONLY in the CI.</div><div dir="ltr" style="font-style: normal;"><br></div><div dir="ltr" style="font-style: normal;">Thanks!<br><font face="Sans Serif, Verdana, Arial, Helvetica, sans-serif">Pushkar N Kulkarni,</font></div>
<div dir="ltr" style="font-style: normal;"><font face="Sans Serif, Verdana, Arial, Helvetica, sans-serif">IBM Runtimes</font></div><div dir="ltr" style="font-style: normal;"><font face="Sans Serif, Verdana, Arial, Helvetica, sans-serif"><br></font></div><div dir="ltr"><font face="serif, Times New Roman, Times, serif"><i>Simplicity is prerequisite for reliability - Edsger W. Dijkstra</i></font></div>
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