# \[ERROR\] InnoDB: MySQL is freeing a thd

**URL:** <https://forums.percona.com/t/error-innodb-mysql-is-freeing-a-thd/5979>\
**Category:** Percona Server for MySQL 5.7\
**Created:** [November 6, 2017, 4:51am UTC](https://forums.percona.com/t/error-innodb-mysql-is-freeing-a-thd/5979 "2017-11-06T04:51:25Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![pablo.barrachina](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/pablo.barrachina/32/39_2.png) [@pablo.barrachina](https://forums.percona.com/u/pablo.barrachina)\
**Post date:** [November 6, 2017, 4:51am UTC](https://forums.percona.com/t/error-innodb-mysql-is-freeing-a-thd/5979/1 "2017-11-06T04:51:25Z")

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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!

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**Author:** ![RoelVandePaar](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/roelvandepaar/32/16893_2.png) [@RoelVandePaar](https://forums.percona.com/u/RoelVandePaar)\
**Post date:** [November 7, 2017, 2:00pm UTC](https://forums.percona.com/t/error-innodb-mysql-is-freeing-a-thd/5979/2 "2017-11-07T14:00:22Z")

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Hi Pablo

Could it be that innodb-thread-concurrency \> 0 and actual Threads\_running \> innodb-thread-concurrency?

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**Author:** ![pablo.barrachina](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/pablo.barrachina/32/39_2.png) [@pablo.barrachina](https://forums.percona.com/u/pablo.barrachina)\
**Post date:** [November 28, 2017, 10:31am UTC](https://forums.percona.com/t/error-innodb-mysql-is-freeing-a-thd/5979/3 "2017-11-28T10:31:50Z")

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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!

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<div class="post-metadata">

**Author:** ![pablo.barrachina](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/pablo.barrachina/32/39_2.png) [@pablo.barrachina](https://forums.percona.com/u/pablo.barrachina)\
**Post date:** [November 30, 2017, 4:07am UTC](https://forums.percona.com/t/error-innodb-mysql-is-freeing-a-thd/5979/4 "2017-11-30T04:07:54Z")

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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?

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<div class="post-metadata">

**Author:** ![pablo.barrachina](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/pablo.barrachina/32/39_2.png) [@pablo.barrachina](https://forums.percona.com/u/pablo.barrachina)\
**Post date:** [March 7, 2018, 2:51pm UTC](https://forums.percona.com/t/error-innodb-mysql-is-freeing-a-thd/5979/5 "2018-03-07T14:51:42Z")

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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!