<div dir="ltr"><div><div>Bartosz,<br><br></div>this looks like a part of our global approach to rewrite pacemaker providers to use crm_diff command instead of cs_shadow/commit approach. ( part of <a href="https://blueprints.launchpad.net/fuel/+spec/ha-pacemaker-improvements">https://blueprints.launchpad.net/fuel/+spec/ha-pacemaker-improvements</a>)<br>
<br></div>If reboot attributes do not help, then we should reconsider this approach as a high priority one. Thank you for the update.<br></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, May 29, 2014 at 3:06 PM, Bartosz Kupidura <span dir="ltr"><<a href="mailto:bkupidura@mirantis.com" target="_blank">bkupidura@mirantis.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hello,<br>
<br>
<br>
Wiadomość napisana przez Vladimir Kuklin <<a href="mailto:vkuklin@mirantis.com">vkuklin@mirantis.com</a>> w dniu 29 maj 2014, o godz. 12:09:<br>
<div class=""><br>
> may be the problem is that you are using liftetime crm attributes instead of 'reboot' ones. shadow/commit is used by us because we need transactional behaviour in some cases. if you turn crm_shadow off, then you will experience problems with multi-state resources and location/colocation/order constraints. so we need to find a way to make commits transactional. there are two ways:<br>
> 1) rewrite corosync providers to use crm_diff command and apply it instead of shadow commit that can swallow cluster attributes sometimes<br>
<br>
</div>In PoC i removed all cs_commit/cs_shadow, and looks that everything is working. But as you says, this can lead to problems with more complicated deployments.<br>
This need to be verified.<br>
<div class=""><br>
> 2) store 'reboot' attributes instead of lifetime ones<br>
<br>
</div>I test with —lifetime forever and reboot. No difference for cs_commit/cs_shadow fail.<br>
<br>
Moreover we need method to store GTID permanent (to support whole cluster reboot).<br>
If we want to stick to cs_commit/cs_shadow, we need other method to store GTID than crm_attribute.<br>
<div class="HOEnZb"><div class="h5"><br>
><br>
><br>
><br>
> On Thu, May 29, 2014 at 12:42 PM, Bogdan Dobrelya <<a href="mailto:bdobrelia@mirantis.com">bdobrelia@mirantis.com</a>> wrote:<br>
> On 05/27/14 16:44, Bartosz Kupidura wrote:<br>
> > Hello,<br>
> > Responses inline.<br>
> ><br>
> ><br>
> > Wiadomość napisana przez Vladimir Kuklin <<a href="mailto:vkuklin@mirantis.com">vkuklin@mirantis.com</a>> w dniu 27 maj 2014, o godz. 15:12:<br>
> ><br>
> >> Hi, Bartosz<br>
> >><br>
> >> First of all, we are using openstack-dev for such discussions.<br>
> >><br>
> >> Second, there is also Percona's RA for Percona XtraDB Cluster, which looks like pretty similar, although it is written in Perl. May be we could derive something useful from it.<br>
> >><br>
> >> Next, if you are working on this stuff, let's make it as open for the community as possible. There is a blueprint for Galera OCF script: <a href="https://blueprints.launchpad.net/fuel/+spec/reliable-galera-ocf-script" target="_blank">https://blueprints.launchpad.net/fuel/+spec/reliable-galera-ocf-script</a>. It would be awesome if you wrote down the specification and sent newer galera ocf code change request to fuel-library gerrit.<br>
> ><br>
> > Sure, I will update this blueprint.<br>
> > Change request in fuel-library: <a href="https://review.openstack.org/#/c/95764/" target="_blank">https://review.openstack.org/#/c/95764/</a><br>
><br>
> That is a really nice catch, Bartosz, thank you. I believe we should<br>
> review the new OCF script thoroughly and consider omitting<br>
> cs_commits/cs_shadows as well. What would be the downsides?<br>
><br>
> ><br>
> >><br>
> >> Speaking of crm_attribute stuff. I am very surprised that you are saying that node attributes are altered by crm shadow commit. We are using similar approach in our scripts and have never faced this issue.<br>
> ><br>
> > This is probably because you update crm_attribute very rarely. And with my approach GTID attribute is updated every 60s on every node (3 updates in 60s, in standard HA setup).<br>
> ><br>
> > You can try to update any attribute in loop during deploying cluster to trigger fail with corosync diff.<br>
><br>
> It sounds reasonable and we should verify it.<br>
> I've updated the statuses for related bugs and attached them to the<br>
> aforementioned blueprint as well:<br>
> <a href="https://bugs.launchpad.net/fuel/+bug/1283062/comments/7" target="_blank">https://bugs.launchpad.net/fuel/+bug/1283062/comments/7</a><br>
> <a href="https://bugs.launchpad.net/fuel/+bug/1281592/comments/6" target="_blank">https://bugs.launchpad.net/fuel/+bug/1281592/comments/6</a><br>
><br>
><br>
> ><br>
> >><br>
> >> Corosync 2.x support is in our roadmap, but we are not sure that we will use Corosync 2.x earlier than 6.x release series start.<br>
> ><br>
> > Yeah, moreover corosync CMAP is not synced between cluster nodes (or maybe im doing something wrong?). So we need other solution for this...<br>
> ><br>
><br>
> We should use CMAN for Corosync 1.x, perhaps.<br>
><br>
> >><br>
> >><br>
> >> On Tue, May 27, 2014 at 3:08 PM, Bartosz Kupidura <<a href="mailto:bkupidura@mirantis.com">bkupidura@mirantis.com</a>> wrote:<br>
> >> Hello guys!<br>
> >> I would like to start discussion on a new resource agent for galera/pacemaker.<br>
> >><br>
> >> Main features:<br>
> >> * Support cluster boostrap<br>
> >> * Support reboot any node in cluster<br>
> >> * Support reboot whole cluster<br>
> >> * To determine which node have latest DB version, we should use galera GTID (Global Transaction ID)<br>
> >> * Node with latest GTID is galera PC (primary component) in case of reelection<br>
> >> * Administrator can manually set node as PC<br>
> >><br>
> >> GTID:<br>
> >> * get GTID from mysqld --wsrep-recover or SQL query 'SHOW STATUS LIKE ‚wsrep_local_state_uuid''<br>
> >> * store GTID as crm_attribute for node (crm_attribute --node $HOSTNAME --lifetime $LIFETIME --name gtid --update $GTID)<br>
> >> * on every monitor/stop/start action update GTID for given node<br>
> >> * GTID can have 3 format:<br>
> >> - XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX:123 - standard cluster-id:commit-id<br>
> >> - XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX:-1 - standard non initialized cluster, 00000000-0000-0000-0000-000000000000:-1<br>
> >> - XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX:INF - commit-id manually set to INF, force RA to create new cluster, with master on given node<br>
> >><br>
> >> Check if reelection of PC is needed:<br>
> >> * (node is located in partition with quorum OR we have only 1 node configured in cluster) AND galera resource is not running on any node<br>
> >> * GTID is manually set to INF on given node<br>
> >><br>
> >> Check if given node is PC:<br>
> >> * have highest GTID in cluster, in case we have more than one node with „highest” GTID, we use CRC32 to choose proper PC.<br>
> >> * GTID is manually set to INF<br>
> >> * in case node with highest GTID will not come back after cluster reboot (for example disk failure) administrator should set GTID to INF on other node<br>
> >><br>
> >> I have almost ready RA: <a href="http://zynzel.spof.pl/mysql-wss" target="_blank">http://zynzel.spof.pl/mysql-wss</a><br>
> >><br>
> >> Tested with vanila centos galera/pacemaker/corosync - OK<br>
> >> Tested with Fuel 4.1 - Fail<br>
> >><br>
> >><br>
> >> Fuel 4.1 with that RA will not deploy correctly, because we use crm_attribute to store GTID, and in manifest we use cs_shadow/cs_commit for every pacemaker resource.<br>
> >> This lead to cs_commit problem with different configuration in shadow copy and running configuration (running config changed by RA).<br>
> >> "Could not commit shadow instance [..] to the CIB: Application of an update diff failed”<br>
> >><br>
> >> To solve this we can go in 2 ways:<br>
> >> 1) dont use cs_commit/cs_shadow in manifests<br>
> >> 2) store GTID in other way than crm_attribute<br>
> >><br>
> >> IMHO 2) is better (less invasive) and we can store GTID in corosync CMAP (<a href="http://www.polarhome.com/service/man/generic.php?qf=corosync-cmapctl" target="_blank">http://www.polarhome.com/service/man/generic.php?qf=corosync-cmapctl</a>), but this require corosync 2.X<br>
> >><br>
> >><br>
> >> --<br>
> >> Mailing list: <a href="https://launchpad.net/~fuel-dev" target="_blank">https://launchpad.net/~fuel-dev</a><br>
> >> Post to : <a href="mailto:fuel-dev@lists.launchpad.net">fuel-dev@lists.launchpad.net</a><br>
> >> Unsubscribe : <a href="https://launchpad.net/~fuel-dev" target="_blank">https://launchpad.net/~fuel-dev</a><br>
> >> More help : <a href="https://help.launchpad.net/ListHelp" target="_blank">https://help.launchpad.net/ListHelp</a><br>
> >><br>
> >><br>
> >><br>
> >> --<br>
> >> Yours Faithfully,<br>
> >> Vladimir Kuklin,<br>
> >> Fuel Library Tech Lead,<br>
> >> Mirantis, Inc.<br>
> >> +7 (495) 640-49-04<br>
> >> +7 (926) 702-39-68<br>
> >> Skype kuklinvv<br>
> >> 45bk3, Vorontsovskaya Str.<br>
> >> Moscow, Russia,<br>
> >> <a href="http://www.mirantis.com" target="_blank">www.mirantis.com</a><br>
> >> <a href="http://www.mirantis.ru" target="_blank">www.mirantis.ru</a><br>
> >> <a href="mailto:vkuklin@mirantis.com">vkuklin@mirantis.com</a><br>
> ><br>
> ><br>
><br>
><br>
> --<br>
> Best regards,<br>
> Bogdan Dobrelya,<br>
> Skype #<a href="http://bogdando_at_yahoo.com" target="_blank">bogdando_at_yahoo.com</a><br>
> Irc #bogdando<br>
><br>
><br>
><br>
> --<br>
> Yours Faithfully,<br>
> Vladimir Kuklin,<br>
> Fuel Library Tech Lead,<br>
> Mirantis, Inc.<br>
> +7 (495) 640-49-04<br>
> +7 (926) 702-39-68<br>
> Skype kuklinvv<br>
> 45bk3, Vorontsovskaya Str.<br>
> Moscow, Russia,<br>
> <a href="http://www.mirantis.com" target="_blank">www.mirantis.com</a><br>
> <a href="http://www.mirantis.ru" target="_blank">www.mirantis.ru</a><br>
> <a href="mailto:vkuklin@mirantis.com">vkuklin@mirantis.com</a><br>
<br>
</div></div></blockquote></div><br><br clear="all"><br>-- <br><div dir="ltr">Yours Faithfully,<br>Vladimir Kuklin,<br>Fuel Library Tech Lead,<br>Mirantis, Inc.<br>+7 (495) 640-49-04<br>+7 (926) 702-39-68<br>Skype kuklinvv<br>
45bk3, Vorontsovskaya Str.<br>Moscow, Russia,<br><a href="http://www.mirantis.ru/" target="_blank">www.mirantis.com</a><br><a href="http://www.mirantis.ru/" target="_blank">www.mirantis.ru</a><br><a href="mailto:vkuklin@mirantis.com" target="_blank">vkuklin@mirantis.com</a></div>
</div>