[ClusterLabs] Colocation constraint for grouping all master-mode stateful resources with important stateless resources

[Andrei Borzenkov]

23.03.2018 20:42, Sam Gardner пишет:
> Thanks, Ken.
> 
> I just want all master-mode resources to be running wherever DRBDFS is running (essentially). If the cluster detects that any of the master-mode resources can't run on the current node (but can run on the other per ethmon), all other master-mode resources as well as DRBDFS should move over to the other node.
> 
> The current set of constraints I have will let DRBDFS move to the standby node and "take" the Master mode resources with it, but the Master mode resources failing over to the other node won't take the other Master resources or DRBDFS.
> 

I do not think it is possible. There is no way to express symmetrical
colocation rule like "always run A and B together". You start with A and
place B relative to A; but then A is not affected by B's state.
Attempting now to place A relative to B will result in a loop and is
ignored. See also old discussion:

https://lists.gt.net/linuxha/pacemaker/68099


> As a side note, there are other resources I have in play (some active/passive like DRBDFS, some Master/Slave like the ship resources) that are related, but not shown here - I'm just having a hard time reasoning about the generalized form that my constraints should take to make this sort of thing work.
>