From 835122560f5ae0c7e973f210f251a85b06a18ddd Mon Sep 17 00:00:00 2001 From: Jeremy Stanley Date: Mon, 30 Nov 2020 16:04:13 +0000 Subject: [PATCH] Increase some of Gerrit's in-memory cache pools We're seeing high system load and decreased performance on our production Gerrit instance. Some research suggests this may be I/O contention which can be relieved through better caching: https://groups.google.com/g/repo-discuss/c/7CemrH4lVJE According to `gerrit show-caches --show-jvm --show-threads` some of our memory-only caches are already at their default maximums after only a few days of operation, and one in particular (changeid_project) has a particularly poor cache hit ratio of 24% at the moment. Increase changeid_project from the 1024 entry default by 32x (manual tests at 8x approached 50% cache hit), increase projects by 4x (greater than the number of repos we host for now), and double the others (groups_bysubgroup, permission_sort) since they still had reasonable cache hit ratios while full. Also alpha-order the existing cache overrides in our config for improved maintainability. This will require a Gerrit service restart to take effect, once the file update has been deployed. Change-Id: Ieecd1802ce53cc0d37c68476b94b44cbe36fbd6e --- playbooks/roles/gerrit/templates/gerrit.config | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/playbooks/roles/gerrit/templates/gerrit.config b/playbooks/roles/gerrit/templates/gerrit.config index acdb33aff5..df063cf446 100644 --- a/playbooks/roles/gerrit/templates/gerrit.config +++ b/playbooks/roles/gerrit/templates/gerrit.config @@ -47,16 +47,24 @@ maxQueued = 200 [cache] directory = cache -[cache "web_sessions"] - maxAge = 7days [cache "accounts"] memoryLimit = 32768 [cache "accounts_byemail"] memoryLimit = 32768 [cache "accounts_byname"] memoryLimit = 32768 +[cache "changeid_project"] + memoryLimit = 32768 +[cache "groups_bysubgroup"] + memoryLimit = 2048 [cache "groups_byuuid"] memoryLimit = 32768 +[cache "permission_sort"] + memoryLimit = 2048 +[cache "projects"] + memoryLimit = 4096 +[cache "web_sessions"] + maxAge = 7days [user] email = review@openstack.org [change]