Andrew Beekhof wrote:
> On Apr 5, 2007, at 4:48 PM, Alan Robertson wrote:
>
>> Alan Robertson wrote:
>>> Lars Marowsky-Bree wrote:
>>>> On 2007-04-04T11:41:44, Doug Knight <[EMAIL PROTECTED]> wrote:
>>>>
>>>>> The key word in my question was "thinks". It would be useful to the RA
>>>>> if it could know what state the CRM thought it was in, so in case
>>>>> the RA
>>>>> determines on its own that its already in that state, it doesn't
>>>>> have to
>>>>> do anything. But, if the RA finds that the CRM thinks its in a
>>>>> different
>>>>> state, then the RA could set the CRM straight by calling the
>>>>> crm_master
>>>>> with the appropriate value. Make sense?
>>>> No. The state the resource is in is not set via crm_master, but using
>>>> the exit code of the monitor operation.
>>>>
>>>> You should only call crm_master when you wish to change the
>>>> _preference_
>>>> for master-state.
>>>
>>> But, I think you can use crm_master to retrieve your current preference,
>>> and thereby eliminate unnecessary CIB updates.
>>>
>>> Or maybe crm_master should do that filtering on its own??
>>
>> Attached is a straightforward patch to crm_attribute.c which I believe
>> does this...
>>
>> It also eliminates certain other "do-nothing" attribute changes -
>> because this code is shared by a few different commands.
>>
>> I recognize that this is slightly less efficient for those cases where
>> the attribute is actually going to be changed, but it is _vastly_ more
>> efficient for those cases where the current value is correct - because
>> it eliminates triggering a computation cycle of the policy engine.
>
> I'm not sure how I missed this previously, but this statement is just
> not true.
>
> If the only change to the CIB is to "num_updates", then the PE is never
> re-invoked.
> This has been the case for about as long as I can remember.
This whole discussion started with evidence that this wasn't happening.
I didn't know it was _supposed_ to happen, so I didn't think it odd.
--
Alan Robertson <[EMAIL PROTECTED]>
"Openness is the foundation and preservative of friendship... Let me
claim from you at all times your undisguised opinions." - William
Wilberforce
_______________________________________________________
Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org
http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
Home Page: http://linux-ha.org/
