The question in brief: Is it possible to configure heartbeat such that a managed resource (an IPaddr) is affected by the status of an unmanaged resource?
In theory I could possibly set up a process outside of heartbeat that periodically checks the status of the service in question, and updates an attribute in the CIB. I can then add a constraint which makes it "highly undesirable" for the IPaddr to be placed on a node where the service in question is broken. Is this the best way of going about this? The question in full: I've got a working squid + IPaddr setup with heartbeat 2.1.3 in a two node cluster. There are IP addresses bound to the loopback interface on both nodes which squid listens on, and which the firewall forwards connections to. The firewall routes the subnet these addresses live on to the IP address managed by heartbeat, so whichever node has the magic IP is the currently active proxy. With the current setup, squid is managed by heartbeat, which means it stops it running on the inactive node. This results in a delay of a few seconds if the currently active node changes, as heartbeat first moves the IP address, then stops squid on the old host, and starts it on the new one. I would like to avoid this delay, as it's not actually necessary for squid to be stopped on the inactive node. However, I do want heartbeat to monitor whether squid is running on a node so it can avoid moving the IP address to a node which isn't actually running squid. Squid itself has crash recovery, so it's unlikely heartbeat will be able to get it running again just by running the startup script for it. I've looked at the "is_managed" attribute, but it appears setting a resource to unmanaged prevents any actions, including monitor, from being performed on it. Actually, it seems to check the status at startup, but never again. Is there any way of configuring HA so that it will periodically check the status of squid on all nodes (regardless of whether the node is currently holding the IPaddr resource), so that I can use squid's status as an input to resource constraints? Or, am I completely insane to want to do this in the first place? My reasoning is that squid will be running on both nodes at all times, unless there's something horribly wrong or the administrator has decided to stop it for some reason. Therefore, it will probably just create confusion if heartbeat takes it upon itself to start and stop squid. In addition, I would prefer to minimise downtime, and since there's no harm in having squid running on an inactive node this seems an easy way to shave a few seconds off of the failover delay. _______________________________________________ Linux-HA mailing list Linux-HA@lists.linux-ha.org http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
