674067 - [pamo] Switch to pylibmc

Status: RESOLVED FIXED

(mozilla.org Graveyard :: Server Operations, task)

Description

[Jeff Balogh (:jbalogh)]

pylibmc is a wrapper around libmemcached (C lib) so it serializes/deserializes data from memcached faster. This should help our CPU load and response time.

1. Build/install pyblibmc as a system lib (http://pypi.python.org/pypi/pylibmc).
2. Remove CACHE_BACKEND from settings_local.py
3. Add this to settings_local.py instead:

CACHES = {
    'default': {
      # 'BACKEND': 'django.core.cache.backends.memcached.MemcachedCache',
        'BACKEND': 'django.core.cache.backends.memcached.PyLibMCCache',
        'LOCATION': [
            '10.2.81.12:11211',
        ],                                                                      
        'TIMEOUT': 500,
    },
}

Django 1.3 replaced CACHE_BACKEND with the CACHES dict. The first (commented-out) backend would make our setup identical to the current scheme. The second backend switches to pylibmc.

I'd like to roll this out on prod separately from the move to phx so we can measure the improvement, but we can switch -dev as soon as you're ready.

I built pylibmc 1.2 against libmemcached 0.43 and zamboni runs fine locally.

Comment 1

[Jeremy Orem [:oremj]]

We have to roll different packages for RHEL 5 and RHEL 6. Since PHX is going to be RHEL 6 I'm just going to make this bug dependent on the PHX move.

Comment 2

[Jeff Balogh (:jbalogh)]

Please install the rpm on hudson as well.

Comment 3

[Wil Clouser [:clouserw]]

and khan.  we should keep the whole stack consistent.

Comment 4

[Jeremy Orem [:oremj]]

Both services will need to be moved to a RHEL 6 server to be consistent.

Comment 5

[Jeremy Orem [:oremj]]

Switched to pylibmc on dev.