# Many unauthenticated user thread after start slave **URL:** \ **Category:** Percona Server for MySQL 8.0\ **Created:** [January 3, 2022, 2:18am UTC](https://forums.percona.com/t/many-unauthenticated-user-thread-after-start-slave/13740 "2022-01-03T02:18:43Z")\ **Posts on this page:** 6\ **Page:** 1
**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:** [January 3, 2022, 2:18am UTC](https://forums.percona.com/t/many-unauthenticated-user-thread-after-start-slave/13740/1 "2022-01-03T02:18:43Z")
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. Replication does not use ssl ``` Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 0 ``` Master\_SSL\_Verify\_Server\_Cert: No Last\_IO\_Errno: 0 Last\_IO\_Error: | 200562 | unauthenticated user | connecting host | NULL | Connect | 7846 | login | NULL | 7845709 | 0 | 0 | | 200754 | unauthenticated user | connecting host | NULL | Connect | 7350 | login | NULL | 7349367 | 0 | 0 | | 201778 | unauthenticated user | connecting host | NULL | Connect | 5041 | login | NULL | 5041047 | 0 | 0 | | 201394 | unauthenticated user | connecting host | NULL | Connect | 5952 | login | NULL | 5951720 | 0 | 0 | | 203442 | unauthenticated user | connecting host | NULL | Connect | 1266 | login | NULL | 1265409 | 0 | 0 | | 200946 | unauthenticated user | connecting host | NULL | Connect | 6905 | login | NULL | 6904952 | 0 | 0 | | 202674 | unauthenticated user | connecting host | NULL | Connect | 3060 | login | NULL | 3060046 | 0 | 0 | | 201330 | unauthenticated user | connecting host | NULL | Connect | 6120 | login | NULL | 6120046 | 0 | 0 | | 201714 | unauthenticated user | connecting host | NULL | Connect | 5160 | login | NULL | 5160037 | 0 | 0 | | 202226 | unauthenticated user | connecting host | NULL | Connect | 4026 | login | NULL | 4025437 | 0 | 0 | | 202482 | unauthenticated user | connecting host | NULL | Connect | 3378 | login | NULL | 3377939 | 0 | 0 | | 203378 | unauthenticated user | connecting host | NULL | Connect | 1380 | login | NULL | 1379881 | 0 | 0 | | 202162 | unauthenticated user | connecting host | NULL | Connect | 4188 | login | NULL | 4187940 | 0 | 0 | | 202802 | unauthenticated user | connecting host | NULL | Connect | 2760 | login | NULL | 2760046 | 0 | 0 | | 203058 | unauthenticated user | connecting host | NULL | Connect | 2090 | login | NULL | 2089366 | 0 | 0 | | 203314 | unauthenticated user | connecting host | NULL | Connect | 1500 | login | NULL | 1499366 | 0 | 0 | | 202930 | unauthenticated user | connecting host | NULL | Connect | 2430 | login | NULL | 2429366 | 0 | 0 | | 203634 | unauthenticated user | connecting host | NULL | Connect | 840 | login | NULL | 839367 | 0 | 0 | | 203506 | unauthenticated user | connecting host | NULL | Connect | 1145 | login | NULL | 1144937 | 0 | 0 | | 203698 | unauthenticated user | connecting host | NULL | Connect | 668 | login | NULL | 667939 | 0 | 0 | | 203954 | unauthenticated user | connecting host | NULL | Connect | 18 | login | NULL | 17939 | 0 | 0 | | 203762 | unauthenticated user | connecting host | NULL | Connect | 491 | login | NULL | 490252 | 0 | 0 | | 203890 | unauthenticated user | connecting host | NULL | Connect | 166 | login | NULL | 166012 | 0 | 0 | ±-------±---------------------±----------------±-----±--------±-------±------±-----±----------±----------±--------------+ 1680 rows in set (0.01 sec) ---
**Author:** ![przemek](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/przemek/32/3_2.png) [@przemek](https://forums.percona.com/u/przemek)\ **Post date:** [January 3, 2022, 8:09am UTC](https://forums.percona.com/t/many-unauthenticated-user-thread-after-start-slave/13740/2 "2022-01-03T08:09:17Z")
Can you connect to the source server from the same replica using a regular mysql client and the same user? If so, does the same issue happen? ---
**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:** [January 3, 2022, 8:37am UTC](https://forums.percona.com/t/many-unauthenticated-user-thread-after-start-slave/13740/3 "2022-01-03T08:37:49Z")
yes,I can connect the master server from the slave by using replication user, if use mysql client connects to the master, the issue can’t happen, once start io thread , unauthenticated user become more and more on master. Replication is working fine and this is a production cluster Slave\_IO\_Running: Yes Slave\_SQL\_Running: Yes I use thread-pool and application use long connection | thread\_handling | pool-of-threads | | thread\_pool\_high\_prio\_mode | transactions | | thread\_pool\_high\_prio\_tickets | 4294967295 | | thread\_pool\_idle\_timeout | 60 | | thread\_pool\_max\_threads | 100000 | | thread\_pool\_oversubscribe | 7 | | thread\_pool\_size | 64 | | thread\_pool\_stall\_limit | 50 | | thread\_stack | 286720 | | thread\_statistics | OFF | ---
**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:** [January 10, 2022, 8:22am UTC](https://forums.percona.com/t/many-unauthenticated-user-thread-after-start-slave/13740/4 "2022-01-10T08:22:28Z")
After I disabled the thread pool, the issue doesn’t happen. ---
**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, 7:46pm UTC](https://forums.percona.com/t/many-unauthenticated-user-thread-after-start-slave/13740/5 "2024-04-24T19:46:36Z")
Why does slave connection to master result in unauthenticated user even though there is still a connection that is intact between master and slave. Why will it try to reconnect again and again. ---
**Author:** ![jinyou.ma](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/jinyou.ma/32/19714_2.png) [@jinyou.ma](https://forums.percona.com/u/jinyou.ma)\ **Post date:** [January 9, 2025, 2:51am UTC](https://forums.percona.com/t/many-unauthenticated-user-thread-after-start-slave/13740/6 "2025-01-09T02:51:03Z")
Please check if you are facing the bug [https://perconadev.atlassian.net/browse/PS-9614](https://perconadev.atlassian.net/browse/PS-9614) You can check the timer thread with command below ```auto ps -T -p $(pidof mysqld) | grep timer_th ```