On Dec 13, 2013, at 8:06 PM, Isaku Yamahata <[email protected]> wrote:
> On Fri, Dec 06, 2013 at 04:30:17PM +0900, > Maru Newby <[email protected]> wrote: > >> >> On Dec 5, 2013, at 5:21 PM, Isaku Yamahata <[email protected]> wrote: >> >>> On Wed, Dec 04, 2013 at 12:37:19PM +0900, >>> Maru Newby <[email protected]> wrote: >>> >>>> In the current architecture, the Neutron service handles RPC and WSGI with >>>> a single process and is prone to being overloaded such that agent >>>> heartbeats can be delayed beyond the limit for the agent being declared >>>> 'down'. Even if we increased the agent timeout as Yongsheg suggests, >>>> there is no guarantee that we can accurately detect whether an agent is >>>> 'live' with the current architecture. Given that amqp can ensure eventual >>>> delivery - it is a queue - is sending a notification blind such a bad >>>> idea? In the best case the agent isn't really down and can process the >>>> notification. In the worst case, the agent really is down but will be >>>> brought up eventually by a deployment's monitoring solution and process >>>> the notification when it returns. What am I missing? >>>> >>> >>> Do you mean overload of neutron server? Not neutron agent. >>> So event agent sends periodic 'live' report, the reports are piled up >>> unprocessed by server. >>> When server sends notification, it considers agent dead wrongly. >>> Not because agent didn't send live reports due to overload of agent. >>> Is this understanding correct? >> >> Your interpretation is likely correct. The demands on the service are going >> to be much higher by virtue of having to field RPC requests from all the >> agents to interact with the database on their behalf. > > Is this strongly indicating thread-starvation. i.e. too much unfair > thread scheduling. > Given that eventlet is cooperative threading, should sleep(0) to > hogging thread? I'm afraid that's a question for a profiler: https://github.com/colinhowe/eventlet_profiler m. _______________________________________________ OpenStack-dev mailing list [email protected] http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
