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<div class="">As discussed on the Cinder channel, I’ve opened </div>


<div class=""><br class="">


</div>


<div class=""><a href="https://bugs.launchpad.net/oslo.db/+bug/1692956" class="">https://bugs.launchpad.net/oslo.db/+bug/1692956</a></div>


<div class=""><br class="">


</div>


<div class="">to see if oslo.db would be a good place to produce a warning when it detects</div>


<div class="">this potential misconfiguration.</div>


<div class=""><br class="">


</div>


<div class="">Cheers,</div>


<div class=""> Arne</div>


<div class=""><br class="">


</div>


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<blockquote type="cite" class="">


<div class="">On 23 May 2017, at 17:25, Sean McGinnis <<a href="mailto:sean.mcginnis@gmx.com" class="">sean.mcginnis@gmx.com</a>> wrote:</div>


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<div class="">Just wanted to put this out there to hopefully spread awareness and<br class="">


prevent it from happening more.<br class="">


<br class="">


We had a bug reported in Cinder of hitting a deadlock when attempting<br class="">


to deelte multiple volumes simultaneously:<br class="">


<br class="">


<a href="https://bugs.launchpad.net/cinder/+bug/1685818" class="">https://bugs.launchpad.net/cinder/+bug/1685818</a><br class="">


<br class="">


Some were seeing it, but others were not able to reproduce the error<br class="">


in their environments.<br class="">


<br class="">


What it came down to is the use of "mysql://" vs "mysql+pymysql://"<br class="">


for the database connection string. Big thanks to Gerhard Muntingh<br class="">


for noticing this difference.<br class="">


<br class="">


Basically, when using "mysql://" for the connection string, that uses<br class="">


blocking calls that prevent other "threads" from running at the same<br class="">


time, causing these deadlocks.<br class="">


<br class="">


This doesn't just impact Cinder, so I wanted to get the word out that<br class="">


it may be worth checking your configurations and make sure you are<br class="">


using "mysql+pymysql://" for your connections.<br class="">


<br class="">


Sean<br class="">


<br class="">


<br class="">


_______________________________________________<br class="">


OpenStack-operators mailing list<br class="">


OpenStack-operators@lists.openstack.org<br class="">


http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators<br class="">


</div>


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</blockquote>


</div>


<br class="">


<div class="">--<br class="">


Arne Wiebalck<br class="">


CERN IT </div>


<br class="">


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