diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/source/admin/troubleshoot.rst | 1 | ||||
| -rw-r--r-- | doc/source/admin/ts-db-cpu-spikes.rst | 37 |
2 files changed, 38 insertions, 0 deletions
diff --git a/doc/source/admin/troubleshoot.rst b/doc/source/admin/troubleshoot.rst index c597f3bf4..0446cb4ac 100644 --- a/doc/source/admin/troubleshoot.rst +++ b/doc/source/admin/troubleshoot.rst @@ -18,3 +18,4 @@ Storage installation. ts-no-emulator-x86-64.rst ts-non-existent-host.rst ts-non-existent-vlun.rst + ts-db-cpu-spikes.rst diff --git a/doc/source/admin/ts-db-cpu-spikes.rst b/doc/source/admin/ts-db-cpu-spikes.rst new file mode 100644 index 000000000..ddafd73fb --- /dev/null +++ b/doc/source/admin/ts-db-cpu-spikes.rst @@ -0,0 +1,37 @@ +===================================== +Database CPU spikes during operations +===================================== + +Query load upon the database can become a bottleneck that cascades across a +deployment and ultimately degrades not only the Cinder service but also the +whole OpenStack deployment. + +Often, depending on load, query patterns, periodic tasks, and so on and so +forth, additional indexes may be needed to help provide hints to the database +so it can most efficently attempt to reduce the number of rows which need to +be examined in order to return a result set. + +Adding indexes +-------------- + +In older releases, before 2023.1 (Antelope), there were some tables that +performed poorly in the presence of a large number of deleted resources +(volumes, snapshots, backups, etc) which resulted in high CPU loads on the DB +servers not only when listing those resources, but also when doing some +operations on them. This was resolved by adding appropriate indexes to them. + +This example below is specific to MariaDB/MySQL, but the syntax should be easy +to modify for operators using PostgreSQL, and it represents the changes that +older releases could add to resolve these DB server CPU spikes in such a way +that they would not conflict with the ones that Cinder introduced in 2023.1 +(Antelope). + +.. code-block:: sql + + use cinder; + create index groups_deleted_project_id_idx on groups (deleted, project_id); + create index group_snapshots_deleted_project_id_idx on groups (deleted, project_id); + create index volumes_deleted_project_id_idx on volumes (deleted, project_id); + create index volumes_deleted_host_idx on volumes (deleted, host); + create index snapshots_deleted_project_id_idx on snapshots (deleted, project_id); + create index backups_deleted_project_id_idx on backups (deleted, project_id); |