Check privileges on backup start

[Alexey Kopytov]

XtraBackup documentation provides information on connection privileges required by innobackupex depending on options: http://www.percona.com/doc/percona-xtrabackup/innobackupex/privileges.html

The problem is that innobackupex does not check those privileges on startup. The only thing it checks is whether it is able to connect to the server. If that works, it then proceeds to copy InnoDB tables.

Which means it can take hours after starting a backup and before a user can discover innobackupex does not have sufficient privileges to execute FTWRL or start/stop the slave thread, etc., or there's a typo in credentials.

Checking the privileges on backup start and aborting would be a nice usability improvement.

[Vasily Nemkov (vasily.nemkov)]

PR: https://github.com/percona/percona-xtrabackup/pull/372

[Vasily Nemkov (vasily.nemkov)]

Added an option '--check-privileges', in pxb was executed with that option, backup may terminate right after starting if some of the required privileges are missing. However, there is a level of uncertainty and some missing privileges may not be required to perform a backup, those are marked as warnings and backup is not aborted.

[Vasily Nemkov (vasily.nemkov)]

Porting to 2.4

[Vasily Nemkov (vasily.nemkov)]

merged into 2.4: https://github.com/percona/percona-xtrabackup/pull/382

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PXB-39