<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">You can do Active/Active DB with a load balanced VIP, but that’s beyond the scope of “minimum scale”<div><br><div><div>On Jun 18, 2014, at 2:30 PM, Clint Byrum <<a href="mailto:clint@fewbar.com">clint@fewbar.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">Excerpts from Alex Leonhardt's message of 2014-06-18 13:51:41 -0700:<br><blockquote type="cite">hi guys,<br><br>am looking for some resource which parts of the system are required to be<br>HA - I naturally would do :<br><br>- DB<br>- Rabbit<br>- Controller node/s<br><br>we dont use glance and swift too much and wont really as I'd use it as a<br>private / internal cloud - what other services would you consider needing<br>HA and if so, is it possible to run Active/Active with the DB and Rabbit at<br>least ?<br><br></blockquote><br>Active/Active DB would need to be done using a sync replication system<br>like MySQL cluster or Galera. These both recommend more than 2 nodes.<br>Also there are likely issues with the way OpenStack handles conflicting<br>commits to the database, so Active/Active may not even be possible<br>without a lot of testing.<br><br>RabbitMQ can be run in Active/Active w/ mirrored queues.<br><br>Both of the above would require some kind of STONITH mechanism to be<br>sure that split-brain doesn't corrupt your data.<br><br>All of the OpenStack controller services should be O-K except two that<br>I know of:<br><br>* Ceilometer's collector must be Active/Passive<br>* Neutron L3 agent needs to be Active/Passive unless patches have landed<br> to change that<br><br>_______________________________________________<br>OpenStack-operators mailing list<br><a href="mailto:OpenStack-operators@lists.openstack.org">OpenStack-operators@lists.openstack.org</a><br><a href="http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators">http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators</a></div></blockquote></div><br></div></body></html>