mysqld_safe doesn't restart mysqld after a crash

[Miguel Angel Nieto]

mysqld_safe doesn't restart mysqld after a crash.

130722 01:46:59 mysqld_safe Number of processes running now: 0
130722 01:46:59 mysqld_safe WSREP: not restarting wsrep node automatically

Version: '5.5.30-log' socket: '/var/lib/mysql/mysql.sock' port: 3306 Percona XtraDB Cluster (GPL), wsrep_23.7.4.r3843

[Alex Yurchenko (ayurchen)]

Miguel, this is my code and we don't consider it a bug, but a protection against potential chaos. Generally a node is a part of a cluster and should not be manipulated without considering the whole situation.

[Jay Janssen (jay-janssen)]

Alex, I can appreciate that, though there is a certain slickness to an inconsistent node restarting and fixing itself with an SST. Could we at least make 'max_wsrep_restarts' configurable in the [mysqld_safe] section of the my.cnf?

  if [ -n "$wsrep_restart" ]
  then
    if [ $wsrep_restart -le $max_wsrep_restarts ]
    then
      wsrep_restart=`expr $wsrep_restart + 1`
      log_notice "WSREP: sleeping 15 seconds before restart"
      sleep 15
    else
      log_notice "WSREP: not restarting wsrep node automatically"
      break
    fi
  fi

[Jay Janssen (jay-janssen)]

To clarify, I agree defaulting this to 0 is logical.

[Alex Yurchenko (ayurchen)]

Jay, that's trivial to do - and I would have defaulted it to 1 actually, however in the current form this variable has a mysqld_safe process lifetime and means the total number of restarts during the whole life of the process. That is, at one point it becomes 0 and then on the next crash two months later it will not restart mysqld any more. This is not what people expect, so I hardcoded it to 0 for the time being, so that users don't come to rely on automatic restarts.

To solve this we must reset the counter after every successful cluster join, however I don't know how to achieve that yet, what would be a criterion of "successful cluster join".

[Nilnandan Joshi (nilnandan-joshi)]

As per the Miguel, Alex is right. This is cluster software so things shouldn't just restart automatically. Going to set this to Invalid.

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PXC-1401