[ClusterLabs] Multiple Corosync Instance on a Single Host

[Jan Friesse]

Steven,

 > Hi list,
> I have a situation where I would like to run multiple instances of Corosync, each 'group' on a number of hosts, with each instance providing HA for a dedicated service, thus allowing for benefits around change control, risk management, service/environment separation and the like. The hosts in question run nothing but Docker containers, with the Corosync (+Pacemaker) containers using host mode networking.
> Whilst I can change the UDPU port used by Corosync, a second instance (container) fails with a socket error. Here's the relevant logs:
> Jan 06 13:47:55 [19] rancher-one corosync info    [QB    ] server name: cmapJan 06 13:47:55 [19] rancher-one corosync error   [QB    ] Could not bind AF_UNIX (): Address already in use (98)Jan 06 13:47:55 [19] rancher-one corosync info    [QB    ] withdrawing server socketsJan 06 13:47:55 [19] rancher-one corosync error   [MAIN  ] Can't initialize IPCJan 06 13:47:55 [19] rancher-one corosync error   [SERV  ] Service engine 'corosync_cmap' failed to load for reason 'qb_ipcs_run error'Jan 06 13:47:55 [19] rancher-one corosync error   [MAIN  ] Corosync Cluster Engine exiting with status 20 at service.c:356.
> Can this be overcome? Is there a way to specify a different socket?

Corosync is not designed for running multiple instances. But using 
docker is different story (it's more or less VM, so there should be no 
problem).

You can try to look what socket is already in use (for example use 
strace) but I believe main problem is shared /dev/shm. Can you try to 
mount fresh tmpfs to /dev/shm in docker container?

Regards,
   Honza

> Many thanks in advance.
> Kind regards,
> Steven Ivesonsteve at iveson.eu@sjivesonBlogs: https://packetpushers.net/author/siveson/Books: http://www.amazon.com/Steven-Iveson/e/B00BIR04XM/07734 778 184 		 	   		
>
>
>
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