** Description changed: Release: Ubuntu 10.04 LTS Package Version: 5.1.41-3ubuntu12.6 Stopping a MySQL server can take some time, especially on a busy database. If mysqld gets killed while having open connections, then after the next start you will likely have a lot of tables corrupted. The new upstart mechanism for starting/stopping mysql unfortunately behaves as follows on a "service mysql stop": 1. First it will send a TERM signal to mysqld which is perfectly fine as mysqld will do the same as if you would issue a mysqladmin shutdown command 2. If after 5 seconds the process is still not terminated, a KILL signal will be send. This is really a very big issue since on busy servers lots of myisam tables will be corrupted afterwards Expected behaviour: Send the term signal and wait for a certain amount of time (at least 1 minute). If still not stopped, then simply give an error about this to the user + + == SRU REPORT == + + === IMPACT === + + This has very little impact on a normal running system. It may cause + shutdown to take up to 5 minutes, but that is an acceptable trade off as + recovering a system with crashed tables can take much, much longer. + + === DEV FIX === + + Raising kill timeout to 300 seconds seems a good trade off between + shutdown potentially taking forever, and trying not to corrupt tables. + + === PATCH === + + See merge proposal + + === TEST CASE: === + + This is a race condition, so it is hard to reproduce reliably. However, + if you: + + 1. create a very large innodb table + 2. import a lot of data (inserting more MB of data than your drives can write in 5 seconds should work) + 3. run a very long select on the data in one thread (SELECT * FROM table WHERE column like '%X%';) + 4. DELETE that data in another thread + 5. issue 'stop mysql' immediately after the delete returns. + 6. check to see that mysqld was sent SIGKILL in /var/log/daemon.log + 7. start mysql -- at this point InnoDB recovery will need to be run + + Once the fix is applied, the SIGKILL should never be sent. + + === REGRESSION POTENTIAL === + + The only regression potential is mentioned in the IMPACT section, that + the shutdown of a server or the mysql service may take up to 5 minutes.
-- MySQL upstart stop job does not cleanly shutdown mysql https://bugs.launchpad.net/bugs/620441 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to mysql-dfsg-5.1 in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
