September 22, 2014

Missleading Innodb message on recovery

As I wrote about 2 years ago the feature of Innodb to store copy of master’s position in Slave’s Innodb tablespace got broken. There is a lot of discussions at the corresponding bug report while outcome of the fix remained uncertain for me (the bug is market duplicate while the bugs it seems to be duplicate for describe different issues).
Anyway. The customer came to me today having the following message in the error log after Slave crash while running MySQL 5.1.41 (extra virgin version without XtraDB or Percona Patches)

InnoDB: In a MySQL replication slave the last master binlog file
InnoDB: position 0 10000000, file name mysql-bin.005000
InnoDB: Last MySQL binlog file position 0 20000000, file name ./mysql-bin.003000

He has tried to restart replication from mysql-bin.005000 position 10000000 which failed with “Could not find first log file name in binary log index file” error message

Looking at the Master for this slave I could see its binary log files going only to about 2000, so the binary log file mentioned did not ever exist on this master. What is going on ?
The thing is Innodb does not update this information any more however if it is stored in the tablespace the code is still there to print it. This database was running older MySQL version a while back which was updated to MySQL 5.1 months ago, moved to the new hardware by physical copy and the log file numbers restarted back from 1 but tablespace still contained the ancient data.

I reported the bug on this which should be easy to fix. Otherwise it is easy mistake to make. We also have a patch which restores this information and uses it on slave crash recovery.

About Peter Zaitsev

Peter managed the High Performance Group within MySQL until 2006, when he founded Percona. Peter has a Master's Degree in Computer Science and is an expert in database kernels, computer hardware, and application scaling.

Comments

  1. aspen says:

    did you make a mistake of spelling misleading?

  2. yingkuan says:

    Will show slave status report the same misleading info ?

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