← Back to team overview

maria-developers team mailing list archive

Re: 412e696fd2b: MDEV-25395 server recovery hits replication event checksum error


Hi, Andrei!

fdle changes - ok, I've seen them in 21117.
cur_log/etc - clear.

What are the changes around prev_event_pos for?

On Jul 23, Andrei Elkin wrote:
> revision-id: 412e696fd2b (mariadb-10.3.26-136-g412e696fd2b)
> parent(s): 2fa526e26e8
> author: Andrei Elkin
> committer: Andrei Elkin
> timestamp: 2021-04-15 17:11:07 +0300
> message:
> MDEV-25395 server recovery hits replication event checksum error
> When @@global.binlog_checksum is changing from none to
> crc32 and only the first of two Binlog_checkpoint_log_event gets written to
> the crc32 rotated binlog file before the server crashes, the recovery faces a checksum
> verification error.
> The reason was that recovery algorithm did not realize
> potentially varying binlog checksum at  scanning of
> a sequence of binlog files.
> That is corrected now.
> The master-checksum-verify server recovery aborts now and stops
> the server due to the checksum error.
> A simulation test confirms the fixes.
> Induced changes:
> rpl_cant_read_event_incident got affected because the test
> adopts an external not properly closed binlog file that contains
> events which can't pass checksum verification.
> A work-around is done to accept that binlog and evade recovery.
> binlog_recover_checksum_error needed refinement as
> the master-checksum-verify configured server is made to stop
> due to the checksum error.

VP of MariaDB Server Engineering
and security@xxxxxxxxxxx