[Pacemaker] Unique clone instance is stopped too early on move
Andrew Beekhof
andrew at beekhof.net
Mon Apr 13 02:02:20 EDT 2015
> On 22 Jan 2015, at 12:04 am, Vladislav Bogdanov <bubble at hoster-ok.com> wrote:
>
> 20.01.2015 02:44, Andrew Beekhof wrote:
>>
>>> On 16 Jan 2015, at 3:59 pm, Vladislav Bogdanov <bubble at hoster-ok.com> wrote:
>>>
>>> 16.01.2015 07:44, Andrew Beekhof wrote:
>>>>
>>>>> On 15 Jan 2015, at 3:11 pm, Vladislav Bogdanov <bubble at hoster-ok.com> wrote:
>>>>>
>>>>> 13.01.2015 11:32, Andrei Borzenkov wrote:
>>>>>> On Tue, Jan 13, 2015 at 10:20 AM, Vladislav Bogdanov
>>>>>> <bubble at hoster-ok.com> wrote:
>>>>>>> Hi Andrew, David, all.
>>>>>>>
>>>>>>> I found a little bit strange operation ordering during transition execution.
>>>>>>>
>>>>>>> Could you please look at the following partial configuration (crmsh syntax)?
>>>>>>>
>>>>>>> ===
>>>>>>> ...
>>>>>>> clone cl-broker broker \
>>>>>>> meta interleave=true target-role=Started
>>>>>>> clone cl-broker-vips broker-vips \
>>>>>>> meta clone-node-max=2 globally-unique=true interleave=true resource-stickiness=0 target-role=Started
>>>>>>> clone cl-ctdb ctdb \
>>>>>>> meta interleave=true target-role=Started
>>>>>>> colocation broker-vips-with-broker inf: cl-broker-vips cl-broker
>>>>>>> colocation broker-with-ctdb inf: cl-broker cl-ctdb
>>>>>>> order broker-after-ctdb inf: cl-ctdb cl-broker
>>>>>>> order broker-vips-after-broker 0: cl-broker cl-broker-vips
>>>>>>> ...
>>>>>>> ===
>>>>>>>
>>>>>>> After I put one node to standby and then back to online, I see the following transition (relevant excerpt):
>>>>>>>
>>>>>>> ===
>>>>>>> * Pseudo action: cl-broker-vips_stop_0
>>>>>>> * Resource action: broker-vips:1 stop on c-pa-0
>>>>>>> * Pseudo action: cl-broker-vips_stopped_0
>>>>>>> * Pseudo action: cl-ctdb_start_0
>>>>>>> * Resource action: ctdb start on c-pa-1
>>>>>>> * Pseudo action: cl-ctdb_running_0
>>>>>>> * Pseudo action: cl-broker_start_0
>>>>>>> * Resource action: ctdb monitor=10000 on c-pa-1
>>>>>>> * Resource action: broker start on c-pa-1
>>>>>>> * Pseudo action: cl-broker_running_0
>>>>>>> * Pseudo action: cl-broker-vips_start_0
>>>>>>> * Resource action: broker monitor=10000 on c-pa-1
>>>>>>> * Resource action: broker-vips:1 start on c-pa-1
>>>>>>> * Pseudo action: cl-broker-vips_running_0
>>>>>>> * Resource action: broker-vips:1 monitor=30000 on c-pa-1
>>>>>>> ===
>>>>>>>
>>>>>>> What could be a reason to stop unique clone instance so early for move?
>>>>>>>
>>>>>>
>>>>>> Do not take it as definitive answer, but cl-broker-vips cannot run
>>>>>> unless both other resources are started. So if you compute closure of
>>>>>> all required transitions it looks rather logical. Having
>>>>>> cl-broker-vips started while broker is still stopped would violate
>>>>>> constraint.
>>>>>
>>>>> Problem is that broker-vips:1 is stopped on one (source) node unnecessarily early.
>>>>
>>>> It looks to be moving from c-pa-0 to c-pa-1
>>>> It might be unnecessarily early, but it is what you asked for... we have to unwind the resource stack before we can build it up.
>>>
>>> Yes, I understand that it is valid, but could its stop be delayed until cluster is in the state when all dependencies are satisfied to start it on another node (like migration?)?
>>
>> No, because "we have to unwind the resource stack before we can build it up."
>> Doing anything else would be one of those things that is trivial for a human to identify but rather complex for a computer.
>
> I believe there is also an issue with migration of clone instances.
>
> I modified pe-input to allow migration of cl-broker-vips (and also set inf score for broker-vips-after-broker
> and make cl-broker-vips interleaved).
> Relevant part is:
> clone cl-broker broker \
> meta interleave=true target-role=Started
> clone cl-broker-vips broker-vips \
> meta clone-node-max=2 globally-unique=true interleave=true allow-migrate=true resource-stickiness=0 target-role=Started
> clone cl-ctdb ctdb \
> meta interleave=true target-role=Started
> colocation broker-vips-with-broker inf: cl-broker-vips cl-broker
> colocation broker-with-ctdb inf: cl-broker cl-ctdb
> order broker-after-ctdb inf: cl-ctdb cl-broker
> order broker-vips-after-broker inf: cl-broker cl-broker-vips
>
> After that (part of) transition is:
>
> * Resource action: broker-vips:1 migrate_to on c-pa-0
> * Pseudo action: cl-broker-vips_stop_0
> * Resource action: broker-vips:1 migrate_from on c-pa-1
> * Resource action: broker-vips:1 stop on c-pa-0
> * Pseudo action: cl-broker-vips_stopped_0
> * Pseudo action: all_stopped
> * Pseudo action: cl-ctdb_start_0
> * Resource action: ctdb start on c-pa-1
> * Pseudo action: cl-ctdb_running_0
> * Pseudo action: cl-broker_start_0
> * Resource action: ctdb monitor=10000 on c-pa-1
> * Resource action: broker start on c-pa-1
> * Pseudo action: cl-broker_running_0
> * Pseudo action: cl-broker-vips_start_0
> * Resource action: broker monitor=10000 on c-pa-1
> * Pseudo action: broker-vips:1_start_0
> * Pseudo action: cl-broker-vips_running_0
> * Resource action: broker-vips:1 monitor=30000 on c-pa-1
Have you got the PE file for this?
I feel like we fixed something like this recently but I’d like to check it with your input.
>
> But, I would say that at least from a human logic PoV the above breaks ordering rule broker-vips-after-broker
> (cl-broker-vips finished migrating and thus runs on c-pa-1 before cl-broker started there).
> Technically broker-vips:1_start_0 goes at the right position, but actually resource is "started"
> in migrate_to/mifrate_from.
>
>
> I also went further and injected a pair of non-clone IPAddr2 resources into the same pe-input, and also enabled migration
> for them (returning interleave for cl-broker-vips to false and setting ordering score for broker-vips-after-broker back to 0,
> so all three order constraints are adjacent):
>
> clone cl-broker broker \
> meta interleave=true target-role=Started
> clone cl-broker-vips broker-vips \
> meta clone-node-max=2 globally-unique=true interleave=false allow-migrate=true resource-stickiness=0 target-role=Started
> clone cl-ctdb ctdb \
> meta interleave=true target-role=Started
> primitive broker-vip1 IPaddr2 \
> params ip=192.168.122.70 cidr_netmask=24 nic=eth0 \
> op start interval=0 timeout=20 \
> op stop interval=0 timeout=20 \
> op monitor interval=30
> primitive broker-vip2 IPaddr2 \
> params ip=192.168.122.71 cidr_netmask=24 nic=eth0 \
> op start interval=0 timeout=20 \
> op stop interval=0 timeout=20 \
> op monitor interval=30
> colocation broker-with-ctdb inf: cl-broker cl-ctdb
> colocation broker-vips-with-broker inf: cl-broker-vips cl-broker
> colocation broker-vip1-with-broker inf: broker-vip1 cl-broker
> colocation broker-vip2-with-broker inf: broker-vip2 cl-broker
> colocation broker-vip2-not-with-vip1 -100: broker-vip2 broker-vip1
> order broker-after-ctdb inf: cl-ctdb cl-broker
> order broker-vips-after-broker 0: cl-broker cl-broker-vips
> order broker-vip1-after-broker 0: cl-broker broker-vip1
> order broker-vip2-after-broker 0: cl-broker broker-vip2
>
> For broker-vip2 I see completely different output (compare with broker-vips:1):
>
> * Resource action: broker-vips:1 migrate_to on c-pa-0
> * Pseudo action: cl-broker-vips_stop_0
> * Resource action: broker-vips:1 migrate_from on c-pa-1
> * Resource action: broker-vips:1 stop on c-pa-0
> * Pseudo action: cl-broker-vips_stopped_0
> * Pseudo action: cl-ctdb_start_0
> * Resource action: ctdb start on c-pa-1
> * Pseudo action: cl-ctdb_running_0
> * Pseudo action: cl-broker_start_0
> * Resource action: ctdb monitor=10000 on c-pa-1
> * Resource action: broker start on c-pa-1
> * Pseudo action: cl-broker_running_0
> * Resource action: broker-vip2 migrate_to on c-pa-0
> * Pseudo action: cl-broker-vips_start_0
> * Resource action: broker monitor=10000 on c-pa-1
> * Resource action: broker-vip2 migrate_from on c-pa-1
> * Resource action: broker-vip2 stop on c-pa-0
> * Pseudo action: broker-vips:1_start_0
> * Pseudo action: cl-broker-vips_running_0
> * Pseudo action: all_stopped
> * Pseudo action: broker-vip2_start_0
> * Resource action: broker-vips:1 monitor=30000 on c-pa-1
> * Resource action: broker-vip2 monitor=30000 on c-pa-1
>
> broker-vip2 is migrated much later than broker-vips:1, exactly at the point I would expect to see.
>
> For me that means that some logic already exists which would allow to postpone resource move until
> everything is ready for it at the destination.
>
> I also tried to disable migration for broker-vip2, and in that case it was also stopped too early.
>
> So, there are four cases, and for one of them I get expected result:
> *) g-u clone, migration disabled - early stop
> *) g-u clone, migration enabled - early stop
> *) ordinary resource, migration disabled - early stop
> *) ordinary resource, migration enabled - stop at the expected point
>
> The question is:
>
> Is it strictly impossible to make non-migratable resources behave the same way as that migratable broker-vip2?
>
> (I'm pretty sure I didn't make a mess in details anywhere but I want to recheck that all once again)
>
> Best,
> Vladislav
>
>>
>> Better to look at why broker-vips:1 needed to be moved.
>>
>>>
>>> Like:
>>> ===
>>> * Pseudo action: cl-ctdb_start_0
>>> * Resource action: ctdb start on c-pa-1
>>> * Pseudo action: cl-ctdb_running_0
>>> * Pseudo action: cl-broker_start_0
>>> * Resource action: ctdb monitor=10000 on c-pa-1
>>> * Resource action: broker start on c-pa-1
>>> * Pseudo action: cl-broker_running_0
>>> * Pseudo action: cl-broker-vips_start_0
>>> * Resource action: broker monitor=10000 on c-pa-1
>>> * Pseudo action: cl-broker-vips_stop_0
>>> * Resource action: broker-vips:1 stop on c-pa-0
>>> * Pseudo action: cl-broker-vips_stopped_0
>>> * Resource action: broker-vips:1 start on c-pa-1
>>> * Pseudo action: cl-broker-vips_running_0
>>> * Resource action: broker-vips:1 monitor=30000 on c-pa-1
>>> ===
>>> That would be the great optimization toward five nines...
>>>
>>> Best,
>>> Vladislav
>>>
>>>
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>>
>>
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>>
>
>
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