mysql_upgrade - MySQL server has gone away

[Yaning]

When your my.cnf configurations exceeded ulimit for the mysql user, you will get these warnings as the server is booting up:

2016-02-26T19:01:19.975161Z 0 [Warning] Changed limits: max_open_files: 1024 (requested 17095)
2016-02-26T19:01:19.975218Z 0 [Warning] Changed limits: max_connections: 214 (requested 700)
2016-02-26T19:01:19.975222Z 0 [Warning] Changed limits: table_open_cache: 400 (requested 8192)

Server works fine however.

The problem occurs when you run mysql_upgrade. The upgrade process seems to use the upper limit specified in the my.cnf instead the lower limit that the system allows. Therefore mysql_upgrade will fail after a certain number of tables have been scanned, with lots of error message: "Mysql server has gone away"

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-3386