memcached_servers timeout causes poor API response time

Bug #1293794 reported by Craig Anderson
10
This bug affects 2 people
Affects Status Importance Assigned to Milestone
OpenStack Compute (nova)
Invalid
Wishlist
Unassigned
oslo-incubator
Won't Fix
Undecided
Unassigned

Bug Description

In nova.conf, when configured for HA by setting the memcached_servers parameter to several memcached servers in the nova API cluster, e.g.:

memcached_servers=192.168.50.11:11211,192.168.50.12:11211,192.168.50.13:11211

If there are memcached servers on this list that are down, the time it takes to complete Nova API requests increases from < 1 second to 3-6 seconds.

It seems to me that Nova should protect itself from such performance degradation in an HA scenario.

Tags: compute
Tracy Jones (tjones-i)
tags: added: compute
Revision history for this message
Sahid Orentino (sahid-ferdjaoui) wrote :

This look to be related with the client python-memcached.

https://bugs.launchpad.net/python-memcached/+bug/794550

Revision history for this message
Sahid Orentino (sahid-ferdjaoui) wrote :

Actually after some investigation it looks like we use the version 1.48 and this version handles a param 'socket_timeout' in the client constructor.

We can add a option to configure it.

Changed in nova:
importance: Undecided → Wishlist
status: New → Confirmed
assignee: nobody → sahid (sahid-ferdjaoui)
status: Confirmed → Invalid
Revision history for this message
Sahid Orentino (sahid-ferdjaoui) wrote :

But this is not related to nova. It's related to oslo-incubator

Changed in nova:
assignee: sahid (sahid-ferdjaoui) → nobody
Revision history for this message
Bogdan Dobrelya (bogdando) wrote :

Action items: add new option which configures socket_timeout for python-memcached

Changed in oslo:
status: New → Confirmed
Changed in oslo-incubator:
status: Confirmed → Won't Fix
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