[ClusterLabs] Mutually exclusive resources ?

[Adam Cécile]

On 9/27/23 16:58, Ken Gaillot wrote:
> On Wed, 2023-09-27 at 16:24 +0200, Adam Cecile wrote:
>> On 9/27/23 16:02, Ken Gaillot wrote:
>>> On Wed, 2023-09-27 at 15:42 +0300, Andrei Borzenkov wrote:
>>>> On Wed, Sep 27, 2023 at 3:21 PM Adam Cecile <acecile at le-vert.net>
>>>> wrote:
>>>>> Hello,
>>>>>
>>>>>
>>>>> I'm struggling to understand if it's possible to create some
>>>>> kind
>>>>> of constraint to avoid two different resources to be running on
>>>>> the
>>>>> same host.
>>>>>
>>>>> Basically, I'd like to have floating IP "1" and floating IP "2"
>>>>> always being assigned to DIFFERENT nodes.
>>>>>
>>>>> Is that something possible ?
>>>> Sure, negative colocation constraint.
>>>>
>>>>> Can you give me a hint ?
>>>>>
>>>> Using crmsh:
>>>>
>>>> colcoation IP1-no-with-IP2 -inf: IP1 IP2
>>>>
>>>>> Thanks in advance, Adam.
>>> To elaborate, use -INFINITY if you want the IPs to *never* run on
>>> the
>>> same node, even if there are no other nodes available (meaning one
>>> of
>>> them has to stop). If you *prefer* that they run on different
>>> nodes,
>>> but want to allow them to run on the same node in a degraded
>>> cluster,
>>> use a finite negative score.
>> That's exactly what I tried to do:
>> crm configure primitive Freeradius systemd:freeradius.service op
>> start interval=0 timeout=120 op stop interval=0 timeout=120 op
>> monitor interval=60 timeout=100
>> crm configure clone Clone-Freeradius Freeradius
>>
>> crm configure primitive Shared-IPv4-Cisco-ISE-1 IPaddr2 params
>> ip=10.1.1.1 nic=eth0 cidr_netmask=24 meta migration-threshold=2 op
>> monitor interval=60 timeout=30 resource-stickiness=50
>> crm configure primitive Shared-IPv4-Cisco-ISE-2 IPaddr2 params
>> ip=10.1.1.2 nic=eth0 cidr_netmask=24 meta migration-threshold=2 op
>> monitor interval=60 timeout=30 resource-stickiness=50
>>
>> crm configure location Shared-IPv4-Cisco-ISE-1-Prefer-BRT Shared-
>> IPv4-Cisco-ISE-1 50: infra-brt
>> crm configure location Shared-IPv4-Cisco-ISE-2-Prefer-BTZ Shared-
>> IPv4-Cisco-ISE-2 50: infra-btz
>> crm configure colocation Shared-IPv4-Cisco-ISE-Different-Nodes -100:
>> Shared-IPv4-Cisco-ISE-1 Shared-IPv4-Cisco-ISE-2
>> My hope is that IP1 stays in infra-brt and IP2 goes on infra-btz. I
>> want to allow them to keep running on different host so I also added
>> stickiness. However, I really do not want them to both run on same
>> node so I added a colocation with negative higher score.
>> Does it looks good to you ?
> Yep, that should work.
>
> The way you have it, if there's some sort of problem and both IPs end
> up on the same node, the IP that doesn't prefer that node will move
> back to its preferred node once the problem is resolved. That sounds
> like what you want, but if you'd rather it not move, you could raise
> stickiness above 100.

Hello,

Yes that's actually what I want. Clients are supposed to use both 
addresses so it really does not make any sens to have both IPs assigned 
to the same host.

Thanks a lot for your help