# Threads\_cached is ZERO

**URL:** <https://forums.percona.com/t/threads-cached-is-zero/3711>\
**Category:** Percona XtraDB Cluster 5.x\
**Created:** [August 28, 2014, 10:13am UTC](https://forums.percona.com/t/threads-cached-is-zero/3711 "2014-08-28T10:13:54Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Lelik1985](https://avatars.discourse-cdn.com/v4/letter/l/51bf81/32.png) [@Lelik1985](https://forums.percona.com/u/Lelik1985)\
**Post date:** [August 28, 2014, 10:13am UTC](https://forums.percona.com/t/threads-cached-is-zero/3711/1 "2014-08-28T10:13:54Z")

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Hi  
I have 6 nodes of Percona XtraDB Cluster with version  
Server version: 5.6.19-67.0-56 Percona XtraDB Cluster (GPL), Release 25.6, wsrep\_25.6.r4111

i noticed that there is no cached threads

| Threads\_cached | 0 |  
| Threads\_connected | 1366 |  
| Threads\_created | 3916 |  
| Threads\_running | 1

in config thread\_cache\_size = 1024

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**Author:** ![jjh](https://avatars.discourse-cdn.com/v4/letter/j/41988e/32.png) [@jjh](https://forums.percona.com/u/jjh)\
**Post date:** [August 28, 2014, 11:37am UTC](https://forums.percona.com/t/threads-cached-is-zero/3711/2 "2014-08-28T11:37:38Z")

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Hi,

I’ve noticed the same thing. Sometimes restarting mysql or whole server “fixes” thread cache, but not always.  
Any ideas how to debug why this is happening ?

mysqladmin -r -i 3 ext | grep Threads\_created  
Shows that threads are created all the time.

(Percona-XtraDB-Cluster-galera-3-3.6-1.3190.rhel6.x86\_64  
Percona-XtraDB-Cluster-server-56-5.6.19-25.6.824.el6.x86\_64)

Is thread\_cache\_size= and one-thread-per-connection supported or is it better to try w/pool-of-threads ?

-Jarno