Cache mechanism

On recent versions of the charm (revisions > 27) the cache mechanism is enabled in the charm by default. However, on revision 27 or older, cache mechanism is disabled. It’s recommended to leave the cache enabled because the collection time can easily timeout.

Users can enable or disable the cache and adjust the cache_ttl configuration based on the size of the OpenStack cluster and the duration of the exporter’s collection jobs.

The cache can be enabled or disabled using the cache option:

# enable the cache
juju config openstack-exporter cache=true

# disable the cache
juju config openstack-exporter cache=false

The cache time-to-live option can be changed using the cache_ttl option:

juju config openstack-exporter cache_ttl=600s

The cache can be enabled/disabled at any time. The openstack-exporter service will be restarted using the new config options.

For more details on how the cache works in the exporter, please check: Explanation - Metrics caching