Our cluster appears to have auto-updated last night and since then we’re getting errors relating to wsrep_max_ws_rows.
The odd thing is that they seem to be related to SELECT queries.
Here is an example (it’s an auto-generated query executed by Apigility):
SELECT COUNT(1) AS C
FROM (SELECT sms_log
.* FROM sms_log
) AS original_select
Error Code: 1180. wsrep_max_ws_rows exceeded
The table has about 20 million rows, we have the default 128k value for wsrep_max_ws_rows.
Increasing the value of wsrep_max_ws_rows to an incredibly big number solves the problem.
However, according to https://www.percona.com/doc/percona-xtradb-cluster/5.6/wsrep-system-index.html
How is a variable that is supposed to control rows in a writeset but actually doesn’t do anything affect SELECT queries?