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author | Zuul <zuul@review.opendev.org> | 2021-01-27 21:08:38 +0000 |
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committer | Gerrit Code Review <review@openstack.org> | 2021-01-27 21:08:38 +0000 |
commit | 6bb40f2dfde82ad4eb29fae47aa2196bb03cd67c (patch) | |
tree | b046f206ebcdb440eb3cf087186d9ea17f01c9b9 /doc | |
parent | aade63b217da0a983fa5bcc33bfae338d410ae70 (diff) | |
parent | 8df3d1505a4e034983c609cb6f8f5e9a0fc945f2 (diff) | |
download | swift-6bb40f2dfde82ad4eb29fae47aa2196bb03cd67c.tar.gz |
Merge "Document memcache max size with shard ranges"
Diffstat (limited to 'doc')
-rw-r--r-- | doc/source/deployment_guide.rst | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/doc/source/deployment_guide.rst b/doc/source/deployment_guide.rst index 0417e6a5c..f6fdfbd2a 100644 --- a/doc/source/deployment_guide.rst +++ b/doc/source/deployment_guide.rst @@ -489,6 +489,29 @@ that have available RAM and CPU. Typically Memcached is run on the proxy servers. The ``memcache_servers`` config option in the ``proxy-server.conf`` should contain all memcached servers. +************************* +Shard Range Listing Cache +************************* + +When a container gets :ref:`sharded<sharding_doc>` the root container will still be the +primary entry point to many container requests, as it provides the list of shards. +To take load off the root container Swift by default caches the list of shards returned. + +As the number of shards for a root container grows to more than 3k the memcache default max +size of 1MB can be reached. Care is needed to keep an eye on the current value or resize it +to something like 5MB. + +Memcache has a ``stats sizes`` option that can point out the current size usage. As this +reaches the current max an increase might be in order:: + + # telnet <memcache server> 11211 + > stats sizes + STAT 160 2 + STAT 448 1 + STAT 576 1 + END + + ----------- System Time ----------- |