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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri;mso-fareast-language:EN-US">Would an automatic transform of mysql:// to mysql+pymysql:// be possible? Is there any reason to not have pymysql?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri;mso-fareast-language:EN-US">Tim<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><b><span style="font-family:Calibri;color:black">From:
</span></b><span style="font-family:Calibri;color:black">Arne Wiebalck <Arne.Wiebalck@cern.ch><br>
<b>Date: </b>Tuesday, 23 May 2017 at 17:50<br>
<b>To: </b>Sean McGinnis <sean.mcginnis@gmx.com><br>
<b>Cc: </b>openstack-operators <openstack-operators@lists.openstack.org><br>
<b>Subject: </b>Re: [Openstack-operators] DB deadlocks due to connection string<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:36.0pt">As discussed on the Cinder channel, I’ve opened <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><a href="https://bugs.launchpad.net/oslo.db/+bug/1692956">https://bugs.launchpad.net/oslo.db/+bug/1692956</a><o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">to see if oslo.db would be a good place to produce a warning when it detects<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">this potential misconfiguration.<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Cheers,<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"> Arne<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">On 23 May 2017, at 17:25, Sean McGinnis <<a href="mailto:sean.mcginnis@gmx.com">sean.mcginnis@gmx.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Just wanted to put this out there to hopefully spread awareness and<br>
prevent it from happening more.<br>
<br>
We had a bug reported in Cinder of hitting a deadlock when attempting<br>
to deelte multiple volumes simultaneously:<br>
<br>
<a href="https://bugs.launchpad.net/cinder/+bug/1685818">https://bugs.launchpad.net/cinder/+bug/1685818</a><br>
<br>
Some were seeing it, but others were not able to reproduce the error<br>
in their environments.<br>
<br>
What it came down to is the use of "mysql://" vs "mysql+pymysql://"<br>
for the database connection string. Big thanks to Gerhard Muntingh<br>
for noticing this difference.<br>
<br>
Basically, when using "mysql://" for the connection string, that uses<br>
blocking calls that prevent other "threads" from running at the same<br>
time, causing these deadlocks.<br>
<br>
This doesn't just impact Cinder, so I wanted to get the word out that<br>
it may be worth checking your configurations and make sure you are<br>
using "mysql+pymysql://" for your connections.<br>
<br>
Sean<br>
<br>
<br>
_______________________________________________<br>
OpenStack-operators mailing list<br>
OpenStack-operators@lists.openstack.org<br>
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">--<br>
Arne Wiebalck<br>
CERN IT <o:p></o:p></p>
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<o:p></o:p></p>
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