Thanks for the quick reply and especially the link. It was much better and more thorough in testing than the other shell ra ldap link I found.
> That would be the first python RA. BTW, there was recently posted > slapd RA (implemented in shell), which I should review, but > haven't done that yet. /At any rate, that RA does not support > multi-state resources which I think would be essential. Did you > plan to do that? At any rate, I'd suggest that you check that > code too and then see if you need to do your own implementation. > The thread starts here: > > http://marc.info/?l=linux-ha-dev&m=129666245428850&w=2 Great stuff and very thorough. But it doesn't look like it will work in our config because the files won't exist on the DRBD slave. I will use this as my new example. I'm not sure what you are referring to with "multi-state" resources. Is this in relation to "promote,demote, migrate_to, migrate_from" in the guide, i.e. master vs slave or is there more to it? I plan to support a master and slave later on down the road -- under pressure to get this rolled out now. Is there a good discussion / resource other than the dev guide? I had planned to try to wade through the DRBD RA scripts to figure it out. Why python? Because shell is harder for me to read and I have to make a good clear verbose example for some others who will also be doing some RA's (in python) for our custom apps. > > > The config file for OpenLDAP is stored in > > /etc/ldap/slapd.d/cn=config.ldif. This is on a DRBD > > active-passive system and the /etc/ldap directory is actually a > > symlink to the DRBD controlled share /vcoreshare/etc/ldap. The > > real config file is at > > /vcoreshare/etc/ldap/slapd.d/cn=config.ldif. > > What about the old style configuration? I assume that there are > still quite a few installations/distributions using those. Yes, I have some code for that, using the example slapd init script and the other examples I found, but no test environment for that. > > So I'm trying to be very judicious with every function and > > validation, checking file permissions, etc. But the problem is > > that /etc/ldap/slapd.d/cn=config.ldif is only present on the > > active DRBD node. My validate function checks that the file is > > readable by the user/group that slapd is to run as. Now, as soon > > as I start ldap in the cluster, it starts fine, but validate fails > > on the standby node (because the DRBD volume isn't mounted) and > > crm_mon shows a failed action: > > On probes (monitor with interval 0), some parts of validation > which concern the local node and not the configuration should say > OCF_NOT_RUNNING instead of error. This is exactly that case. No > worries, because if the next action is start validation is > invoked again. Probes are issued by pacemaker to establish if the > resource is running and normally it is expected to be not running > (for instance on node startup). Ah! I have a function that checks for probes but wasn't using it because I didn't quite understand the semantics. Very helpful stuff, thanks! _______________________________________________ Pacemaker mailing list: [email protected] http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker
