[ERROR] InnoDB: MySQL is freeing a thd

MySQL & MariaDB Percona Server for MySQL 5.7
1

Hi All,

From time ago, we are receiving this errors in production environment:

[ERROR] InnoDB: MySQL is freeing a thd though trx->n_mysql_tables_in_use is 1 and trx->mysql_n_tables_locked is 3.

I was searching internet, but only found references from years ago.

Can be a problem? Can anyone help us?

Percona Server 5.7.18
CentOS Linux 7

Thank you!

2

Hi Pablo

Could it be that innodb-thread-concurrency > 0 and actual Threads_running > innodb-thread-concurrency?

3

Hi Roel,

Thanks for your answer. We have innodb-thread-concurrency set to 0 (default), so I think that’s not the problem…

Any ideas?

Thank you!

4

I’ve reading some blogs and I see that could be due to cache configuration.

This is our cache configuration:

query_cache_size=1024M
query_cache_type=ON

It could be possible?

5

Hi, We have disabled the cache configuration, but error continues appearing… any ideas? What’s the meaning of the mysql_n_tables_locked value? Thank you!