openstack/oslo.cache
Code Issues Proposed changes

Correct help text for backend option

Browse Source 
The help for the backend option said that the memcache_pool backend
is recommended.

memcache_pool is there to keep a limited number of thread-associated
connections open rather than a connection for every thread. If you
don't have a huge number of threads it doesn't offer anything.
Keystone is an example of a service where memcache_pool doesn't
improve things -- eventlet isn't supported anymore and more threads
is not useful due to GIL.

As such, the help text is corrected to say to use memcache_pool for
eventlet and dogpile.cache.memcached for servers like keystone.

The help text also mentioned devstack. This is removed because
devstack is a developer tool so shouldn't be mentioned in text
targeted to operators.

Also, fixed the preceeding comment to remove redundant information
and to not mention keystone since this code isn't in keystone
anymore.

Change-Id: I1ffbf23feac623fe0bfbbe49fb3e0159dedf4cfe
This commit is contained in:
Brant Knudson 2016-08-18 13:40:03 -05:00
parent 6e9f7226c8
commit fb1c71d6ae
1 changed files with 10 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
oslo_cache/_opts.py
View File

@ -29,22 +29,20 @@ FILE_OPTIONS = {
'the dogpile.cache region. This applies to any '
'cached method that doesn\'t have an explicit '
'cache expiration time defined for it.'),
# NOTE(morganfainberg): the dogpile.cache.memory acceptable in devstack
# and other such single-process/thread deployments. Running
# dogpile.cache.memory in any other configuration has the same pitfalls
# as the KVS token backend. It is recommended that either Redis or
# NOTE(morganfainberg): It is recommended that either Redis or
# Memcached are used as the dogpile backend for real workloads. To
# prevent issues with the memory cache ending up in "production"
# unintentionally, we register a no-op as the keystone default caching
# backend.
# unintentionally, we register a no-op as the default caching backend.
cfg.StrOpt('backend', default=_DEFAULT_BACKEND,
help='Dogpile.cache backend module. It is recommended '
'that Memcache with pooling '
'(oslo_cache.memcache_pool) or Redis '
'(dogpile.cache.redis) be used in production '
'deployments. Small workloads (single process) '
'like devstack can use the dogpile.cache.memory '
'backend.'),
'that Memcache or Redis (dogpile.cache.redis) be used '
'in production deployments. For eventlet-based or '
'highly threaded servers, Memcache with pooling '
'(oslo_cache.memcache_pool) is recommended. For low '
'thread servers, dogpile.cache.memcached is '
'recommended. Test environments with a single '
'instance of the server can use the '
'dogpile.cache.memory backend.'),
cfg.MultiStrOpt('backend_argument', default=[], secret=True,
help='Arguments supplied to the backend module. '
'Specify this option once per argument to be '