Open Stack

________________________________________
From: Jiang, Yunhong [yunhong.jiang at intel.com]
Sent: Thursday, November 22, 2012 10:46 PM
>> -----Original Message-----
>> From: Sandy Walsh [mailto:sandy.walsh at RACKSPACE.COM]
>> Sent: Friday, November 23, 2012 7:24 AM
>> To: Mark McLoughlin; OpenStack Development Mailing List; Eoghan Glynn
>> Subject: Re: [openstack-dev] [nova][ceilometer] model for ceilo/nova
>> interaction going forward
>>
>> Sorry for the top-post, but there are so many threads on this topic it's nearly
>> impossible to keep track. So please, allow me to repeat myself here.
>>
>> I've outlined a variety of proposals for solving this problem using the existing
>> infrastructure. There's not a large departure needed from where we are today.
>>
>> In a nutshell, for lifecycle/metering purposes:
>> 1. The existing notifiers are sufficient (they don't have to use AMQP)
>> 2. The notification event should be structured with optional components and
>> versioned accordingly.
>> 3. The ceilometer worker pulls in much of the nova common rpc baggage, which
>> is unnecessary (notifications are not rpc calls). Look at the StackTach worker for
>> an example of something lean and mean.
>
>According to the thread, the key challenge of notification mechanism is timeliness, because currently the periodic >task implementation can't guarantee this.
>
>There are some discussion on the ML to use OS thread for the periodic task, if that is implemented, I think >notification method fits very well.

What sort of resolutions are we talking here? Are we talking instrumentation levels (like 1/min?) or usage event levels (perhaps as fast as every 10 minutes)? 

Regardless, could you provide some info on the services that are suffering so badly that eventlet lags the periodic_task for so long? Sounds like a nova bug we should fix? Actually, if we're monitoring green thread counts via the periodic task we should be able to warn upstream monitoring before it becomes an issue.

(mixing real threads with eventlet will be a sure-fire p.i.t.a)

-S

>Thanks
>--jyh

_______________________________________________
OpenStack-dev mailing list
OpenStack-dev at lists.openstack.org
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev