System: Windows Server 2012 R2, MariaDB 10.2.8
We are currently trying to recover from a quasi-crash (it was a normal shutdown, but mysqld won't start up again)
and are having problems with the redo log of InnoDB during start up. If we start with innodb_force_recovery=0,
the process gets to the point where it logs
2019-06-14 9:29:41 14580 [Note] InnoDB: Starting final batch to recover 1150 pages from redo log.
and then gets stuck there. Since there are no further log entries from that point it is not clear if it takes more time or silently fails. We tried waiting for 22 hours, with no visible progress. The process ran with <1% CPU usage and unchanging memory usage, so presumably it stops silently.
We then tried increasing numbers of innodb_force_recovery and at 6 the server finally starts up again by
skipping the redo log entirely. Unfortunately this also starts with read-only. Thus clearing the log by using
innodb_fast_shutdown=0 doesn't appear to do anything on shutdown.
What we need now is a way to clear the redo log with mysqld being offline. Simply deleting the log files
ib_logfile0 and ib_logfile1 doesn't seem to work either, since they somehow get recreated during
start up, which runs into the same problems as above. We're assuming the data somehow is saved in ibdata1,
but we can't delete it from there without also deleting the tablespace.
As a last resort we tried deleting the corrupted database by deleting it's directory from disk (since we can't delete
it within MySQL as it only starts in read-only) and then starting with innodb_force_recovery=3, but once again
the process tries to perform the redo log and then stops because the database doesn't exist.
It seems the best course of action is to somehow start mysqld without performing the redo log or clearing it beforehand, then deleting the corrupted database and restoring it from a backup. But we can't get it to start in write-mode without trying and failing with the redo log. Is there a way to clear it by directly manipulating the files?
