On 8/25/23 19:31, Mark Michelson wrote:
> Thanks for the changes Ales.
> 
> Acked-by: Mark Michelson <[email protected]>
> 
> On 8/24/23 01:29, Ales Musil wrote:
>> Add config option called "northd-backoff-interval-ms" that allows
>> to delay northd engine runs capped by the config option.
>> When the config option is set to 0 or unspecified, the engine
>> will run without any restrictions. If the value >0 we will delay
>> northd engine run by the previous run time capped by the
>> config option.
>>
>> The reason to delay northd is to prevent it from consuming 100%
>> CPU all the time, secondary to that is the batch of NB updates
>> that could be processed in single northd run. With the recent
>> changes to I-P the engine processing updates faster, but not
>> quite fast enough for processing to be faster than NB changes,
>> which in turn can result into northd never going to sleep. With
>> the backoff period enabled northd can sleep and process the DB
>> updates in bigger batch.
>>
>> In addition to process the updates as fast as possible wake the
>> northd immediately if there are changes accumulated over period
>> of 500 ms or bigger.
>>
>> The results are very noticeable during scale testing.
>> Run without any backoff period:
>> northd aggregate CPU 9810% avg / 12765% max
>> northd was spinning at 100% CPU the entire second half of the test.
>>
>> Run with 200 ms max backoff period:
>> northd aggregate CPU 6066% avg / 7689% max
>> northd was around 60% for the second half of the test.
>>
>> One thing to note is that the overall latency was slightly
>> increased from P99 4s to P99 4.1s.
>>
>> Signed-off-by: Ales Musil <[email protected]>
>> ---

Thanks, Ales and Mark, I applied this to the main branch.

Regards,
Dumitru

_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev

Reply via email to