# Percona mysql8.0.23 unauthenticated user after start slave

**URL:** https://forums.percona.com/t/percona-mysql8-0-23-unauthenticated-user-after-start-slave/13722
**Category:** MySQL & MariaDB
**Tags:** mysql, percona, closed-no-reply
**Created:** [December 31, 2021, 8:54am UTC](https://forums.percona.com/t/percona-mysql8-0-23-unauthenticated-user-after-start-slave/13722 "2021-12-31T08:54:32Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![aoerqileng](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/aoerqileng/32/5467_2.png) [@aoerqileng](https://forums.percona.com/u/aoerqileng)
#### Post date: [December 31, 2021, 8:54am UTC](https://forums.percona.com/t/percona-mysql8-0-23-unauthenticated-user-after-start-slave/13722/1 "2021-12-31T08:54:32Z")

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I have a Percona mysql8.0.23 cluster, 1 master with 2 slaves on Ubuntu20, after I start io thread on slave, there are many unauthenticated user on the master, once I stop io thread, they are immediately gone, any ideas how can I troubleshoot? I set skip-name-resolve and there is no unknown ip access master, after I switch master to another machine, the problem still exists.

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### Author: ![Ross\_Chan](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/ross_chan/32/13824_2.png) [@Ross\_Chan](https://forums.percona.com/u/Ross_Chan)
#### Post date: [November 17, 2023, 1:19pm UTC](https://forums.percona.com/t/percona-mysql8-0-23-unauthenticated-user-after-start-slave/13722/2 "2023-11-17T13:19:40Z")

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Switch off thread pool and the problem will go away  
i.e. thread\_handling = one-thread-per-connection

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### Author: ![Sana\_Ansari](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/sana_ansari/32/12585_2.png) [@Sana\_Ansari](https://forums.percona.com/u/Sana_Ansari)
#### Post date: [April 24, 2024, 7:48pm UTC](https://forums.percona.com/t/percona-mysql8-0-23-unauthenticated-user-after-start-slave/13722/3 "2024-04-24T19:48:32Z")

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Why does slave connection to master result in unauthenticated user even though there is still a connection that is intact between master and slave. We can see this in the processlist. Why will it try to reconnect again and again. I have thread handling as pool of threads currently and avg connections to server is 100-200.