Thanks Andrei, Hope my issue is more related to the issue MDEV-30780 optimistic parallel slave hangs after hit an error Trying to reproduce with a minimal database. Attaching the gbd output Regards, Ragul R On Mon, May 22, 2023 at 2:59 PM <andrei.elkin@pp.inet.fi> wrote:
Howyd Ragul,
Hi team,
I have facing a replication issue in my DB setup where we have a master-slave server and replication is ON between the servers.
Environment: MariaDB 10.6.11 DB size: approx. 1TB
While taking mariabackup, at the stage of preparing backup I see some interpretation in replication which I can see in MySQL logs. Backup was successful but the replication is not catching up with the master and able to see the slave worker are getting stuck forever (as per Processlist). Even if we stop the slave SQL thread or stop slave not fixing the issue. (WIthout backup process the replication is working fine without any delays)
By the show-processlist I could suspect MDEV-30780 optimistic parallel slave hangs after hit an error
If you can reproduce it, could you please file a Jira https://jira.mariadb.org/ ticket to include 1. mysqlbinlog output of the replication events (you may need a master binlog for that) being executed by all workers at that time (find the last executed through Show-Slave-Status, or @@global.gtid_slave_pos). 2. slave error log 3. execute on slave gdb -ex 'set height 0' -ex 'thread apply all backtrace' -p "find yourself mariadb-pid"
| 704638 | system user | | NULL | Slave_worker | 113000 | Waiting for prior transaction to commit | NULL | 0.000 | | 704639 | system user | | NULL | Slave_worker | 113000 | closing tables | NULL | 0.000 | | 704641 | system user | | NULL | Slave_worker | 113000 | Waiting for prior transaction to commit | NULL | 0.000 |
To
Replication as a Backup Solution - MariaDB Knowledge Base as per the page "Running the backup from a slave has the advantage of being able to shutdown or lock the slave and perform a backup without any impact on the primary server." Does it mean running a backup in a slave might impact the replication?
Not really. The sentance merely says the master server performance won't be affected when one takes backup on the slave.
If this is expected behavior, do we have any proper way to achieve a backup on a daily basis in the replication server?
Or The backup is not the problem and some other factor (like a deadlock) is affecting the slave thread to lock?
I would think of deadlock.
Cheers,
Andrei