[Pacemaker] RFC: What part of the XML configuration do you hate the most?

[Satomi Taniguchi]

Hi Lars,

Thank you for your reply.


Lars Marowsky-Bree wrote:
> On 2008-09-09T18:37:31, Satomi Taniguchi <taniguchis at intellilink.co.jp> wrote:
> 
[...snip...]
>>  (2) lrmd counts the monitor op's failures of each resource per period-length.
>>      And it ignores the resource's failure until the number of times of that
>>      exceeds the threshold (max-failures-per-period).
> 
> This means that this policy is enforced by the LRM; I'm not sure that's
> perfect. Should this not be handled by the PE?

At first, I also tried to implement this function in PE.
But there were some problems.
(1) PE has no way to clear fail-count.
     When PE knows a resource's failure, the rsc's fail-count has already
     increased. So, it is proper to treat fail-count as the counter of
     failure for this new function, if it is implemented in PE.
     But, for example, when the period is over, it needs to clear the fail-count.
     At present, PE has no way to request something to cib.
     PE's role is to create a graph based on current CIB, not to change it,
     as far as I understand.
     And users may be confused if fail-count is cleared suddenly.
(2) After a resource is failed once, even if it is failed again, lrmd doesn't
     notify crmd of the failure.
     With new function, PE has to know the failure of resource even if it occurs
     consecutively. But normally, the result of monitor operation is notified
     only when it changes.
     In addition, even if lrmd always notify crmd of the resource's failure,
     the rsc's fail-count doesn't increase because magic-number doesn't change.
     That is to say, PE can't detect consecutive failures.
     I tried to the way to cancel the monitor operation of the failed resource
     and set the same op again.
     But in this way, new monitor operation is done immediately,
     then the interval of monitor operation becomes no longer constant.

So, I considered it is more proper to implement the new function in lrmd.

> 
>>  (3) If the value of period-length is 0, lrmd calculates the suitable length of
[...snip...]
>> In addition, I add the function to lrmadmin to show the following information.
>>   i) the time when the period-length started of the specified resource.
>>  ii) the value of the counter of failures of the specified resource.
>> This is the third patch.
> 
> This means that the full cluster state is no longer reflected in the
> CIB. I don't really like that at all.

I see what you mean.
If it is possible, I want to gather all state of the cluster in the CIB, too.
For that purpose, I tried to implement this function in PE, at first.
But it seems _not_ to be possible for the above reasons...

> 
> 
>> +	op_type = ha_msg_value(op->msg, F_LRM_OP);
>> +
>> +	if (STRNCMP_CONST(op_type, "start") == 0) {
>> +		/* initialize the counter of failures. */
>> +		rsc->t_failed = 0;
>> +		rsc->failcnt_per_period = 0;
>> +	}
> 
> What about a resource being promoted to master state, or demoted again?
> Should the counter not be reset then too?

Exactly.
Thank you for your pointing out.

> 
> (The functions are also getting verrry long; maybe factor some code out
> into smaller functions?)

All right.
I will do so.

> 
> 
> Regards,
>     Lars
> 

Best Regards,
Satomi TANIGUCHI