# PMM creating too many connections **URL:** \ **Category:** PMM 2.x\ **Created:** [February 19, 2023, 1:26pm UTC](https://forums.percona.com/t/pmm-creating-too-many-connections/20171 "2023-02-19T13:26:02Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![MikeBerry](https://avatars.discourse-cdn.com/v4/letter/m/b3f665/32.png) [@MikeBerry](https://forums.percona.com/u/MikeBerry)\ **Post date:** [February 19, 2023, 1:26pm UTC](https://forums.percona.com/t/pmm-creating-too-many-connections/20171/1 "2023-02-19T13:26:02Z")
Hi PMM is creating more and more threads so that the threads connected is reaching the maximum set. I am using the latest version of xtradb cluster 8.0.30 and PMM 2.34.0. This only started with the latest version of PMM. If there is no data in the database then the connections do not rise but as soon as there is data in the database the connections just keep rising until it hits the maximum, which was 250, then 1000, now I am trying 10000 just to keep the cluster running. my.cnf # Connections #max\_connections=250 max\_connections=10000 max\_user\_connections=20 Original grant for ‘pmm’@‘localhost’ GRANT SELECT, PROCESS, SUPER, REPLICATION CLIENT, RELOAD, BACKUP\_ADMIN ON _._ TO ‘pmm’@‘localhost’; After reading a few threads I have revoked SUPER from ‘pmm’@‘localhost’; REVOKE SUPER ON _._ FROM ‘pmm’@‘localhost’; so that pmm now has GRANT SELECT, RELOAD, PROCESS, REPLICATION CLIENT ON _._ TO `pmm`@`localhost` GRANT BACKUP\_ADMIN ON _._ TO `pmm`@`localhost` which is supposed to be the temporary fix but this has not solved the issue. The threads connected keeps climbing. Do we have a date when this will be fixed? ---
**Author:** ![Michael\_Coburn](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/michael_coburn/32/18_2.png) [@Michael\_Coburn](https://forums.percona.com/u/Michael_Coburn)\ **Post date:** [February 21, 2023, 3:08pm UTC](https://forums.percona.com/t/pmm-creating-too-many-connections/20171/2 "2023-02-21T15:08:05Z")
Hi @MikeBerry thanks for posting to the Percona forums! You can begin by implementing an [account resource limit](https://dev.mysql.com/doc/refman/8.0/en/user-resources.html), for example capping the number of connections allowed for the monitoring user by including a `WITH MAX_USER_CONNECTIONS 10` directive. You can modify the existing user like this: ```auto ALTER USER pmm@'%' WITH MAX_USER_CONNECTIONS 10; ``` I see you are already experimenting with setting this variable at the global level. I suggest you remove it there and set it only at the per-user level. Once this is implemented, restart PMM ```auto sudo systemctl restart pmm-agent ``` Then observe whether the connections are again spiking. If so, capture the output of `SHOW PROCESSLIST` and share it here so we can review. You should see a maximum of 10 connections by the `pmm` user and therefore should not be seeing an error of `too many connections`. ---
**Author:** ![MikeBerry](https://avatars.discourse-cdn.com/v4/letter/m/b3f665/32.png) [@MikeBerry](https://forums.percona.com/u/MikeBerry)\ **Post date:** [February 22, 2023, 7:42pm UTC](https://forums.percona.com/t/pmm-creating-too-many-connections/20171/3 "2023-02-22T19:42:58Z")
Hi @Michael_Coburn thanks for the reply. I did what you said, alter pmm user and restart pmm-agent. However pmm is still creating connections and leaving them sleeping as readonly then creating more. showprocesslist below - If I stop the pmm-agent then threads connected decreases slowly and the readonly sleeping connections slowly disappear. mysql\> show processlist; ±----±----------------±------------------------------------±-----±--------±-----±-------------------------------------±-----------------------------------------------------------------------------------------------------±--------±----------±--------------+ | Id | User | Host | db | Command | Time | State | Info | Time\_ms | Rows\_sent | Rows\_examined | ±----±----------------±------------------------------------±-----±--------±-----±-------------------------------------±-----------------------------------------------------------------------------------------------------±--------±----------±--------------+ | 1 | system user | | NULL | Sleep | 952 | innobase\_commit\_low (-1) | NULL | 952499 | 0 | 0 | | 2 | system user | | NULL | Sleep | 952 | wsrep aborter idle | NULL | 952499 | 0 | 0 | | 7 | event\_scheduler | localhost | NULL | Daemon | 949 | Waiting on empty queue | NULL | 949226 | 0 | 0 | | 10 | system user | | NULL | Sleep | 949 | wsrep: applier idle | NULL | 949224 | 0 | 0 | | 11 | system user | | NULL | Sleep | 949 | wsrep: applier idle | NULL | 949224 | 0 | 0 | | 12 | system user | | NULL | Sleep | 949 | wsrep: applier idle | NULL | 949224 | 0 | 0 | | 13 | system user | | NULL | Sleep | 949 | wsrep: applier idle | NULL | 949223 | 0 | 0 | | 14 | system user | | NULL | Sleep | 949 | wsrep: applier idle | NULL | 949223 | 0 | 0 | | 15 | system user | | NULL | Sleep | 949 | wsrep: applier idle | NULL | 949223 | 0 | 0 | | 16 | system user | | NULL | Sleep | 949 | wsrep: applier idle | NULL | 949223 | 0 | 0 | | 46 | mberry | 192.168.164.131:20915 | NULL | Sleep | 0 | | NULL | 215 | 56 | 143 | | 47 | mberry | 192.168.164.131:20916 | NULL | Sleep | 2 | | NULL | 2184 | 614 | 614 | | 56 | mberry | 192.168.164.131:20917 | NULL | Sleep | 515 | | NULL | 514771 | 0 | 0 | | 57 | mberry | 192.168.164.131:20918 | NULL | Sleep | 515 | | NULL | 514771 | 0 | 0 | | 126 | mberry | DBA-Win10-Prod1.crowngp.local:35432 | NULL | Sleep | 94 | | NULL | 94285 | 0 | 0 | | 127 | mberry | DBA-Win10-Prod1.crowngp.local:35433 | NULL | Sleep | 94 | | NULL | 94284 | 0 | 0 | | 136 | mberry | 192.168.164.131:20926 | NULL | Sleep | 51 | | NULL | 51284 | 0 | 0 | | 137 | mberry | 192.168.164.131:20927 | NULL | Sleep | 51 | | NULL | 51283 | 0 | 0 | | 279 | pmm | localhost:38738 | NULL | Query | 151 | Opening tables | SELECT TABLE\_SCHEMA, TABLE\_NAME, TABLE\_TYPE, ifnull(ENGINE, ‘NONE’) as ENGIN | 150877 | 69 | 0 | | 282 | pmm | localhost:38770 | NULL | Query | 151 | Opening tables | SELECT t.table\_schema, t.table\_name, column\_name, auto\_increment, pow(2, case data\_type wh | 150877 | 520 | 0 | | 308 | pmm | localhost:38996 | NULL | Query | 91 | Opening tables | SELECT TABLE\_SCHEMA, TABLE\_NAME, TABLE\_TYPE, ifnull(ENGINE, ‘NONE’) as ENGIN | 90881 | 60 | 0 | | 311 | pmm | localhost:39012 | NULL | Query | 91 | Opening tables | SELECT t.table\_schema, t.table\_name, column\_name, auto\_increment, pow(2, case data\_type wh | 90899 | 472 | 0 | | 313 | readonly | localhost:39062 | NULL | Connect | 91 | Waiting in connection\_control plugin | NULL | 90879 | 0 | 0 | | 314 | readonly | localhost:39066 | NULL | Connect | 91 | Waiting in connection\_control plugin | NULL | 90810 | 0 | 0 | | 315 | readonly | localhost:39070 | NULL | Connect | 91 | Waiting in connection\_control plugin | NULL | 90729 | 0 | 0 | | 316 | readonly | localhost:39074 | NULL | Connect | 91 | Waiting in connection\_control plugin | NULL | 90610 | 0 | 0 | | 317 | readonly | localhost:39078 | NULL | Connect | 91 | Waiting in connection\_control plugin | NULL | 90609 | 0 | 0 | | 318 | readonly | localhost:39082 | NULL | Connect | 90 | Waiting in connection\_control plugin | NULL | 90435 | 0 | 0 | | 319 | readonly | localhost:39086 | NULL | Connect | 90 | Waiting in connection\_control plugin | NULL | 90336 | 0 | 0 | | 320 | readonly | localhost:39090 | NULL | Connect | 90 | Waiting in connection\_control plugin | NULL | 90194 | 0 | 0 | | 327 | readonly | localhost:39170 | NULL | Connect | 61 | Waiting in connection\_control plugin | NULL | 60836 | 0 | 0 | | 328 | readonly | localhost:39174 | NULL | Connect | 61 | Waiting in connection\_control plugin | NULL | 60751 | 0 | 0 | | 329 | readonly | localhost:39178 | NULL | Connect | 61 | Waiting in connection\_control plugin | NULL | 60671 | 0 | 0 | | 330 | readonly | localhost:39186 | NULL | Connect | 60 | Waiting in connection\_control plugin | NULL | 60535 | 0 | 0 | | 331 | readonly | localhost:39190 | NULL | Connect | 60 | Waiting in connection\_control plugin | NULL | 60374 | 0 | 0 | | 332 | readonly | localhost:39194 | NULL | Connect | 60 | Waiting in connection\_control plugin | NULL | 60285 | 0 | 0 | | 337 | pmm | localhost:39242 | NULL | Query | 31 | Opening tables | SELECT TABLE\_SCHEMA, TABLE\_NAME, TABLE\_TYPE, ifnull(ENGINE, ‘NONE’) as ENGIN | 30883 | 8 | 0 | | 340 | pmm | localhost:39256 | NULL | Sleep | 1 | | NULL | 890 | 0 | 0 | | 341 | pmm | localhost:39258 | NULL | Query | 31 | Opening tables | SELECT t.table\_schema, t.table\_name, column\_name, auto\_increment, pow(2, case data\_type wh | 30892 | 464 | 0 | | 342 | readonly | localhost:39306 | NULL | Connect | 31 | Waiting in connection\_control plugin | NULL | 30882 | 0 | 0 | | 343 | readonly | localhost:39310 | NULL | Connect | 31 | Waiting in connection\_control plugin | NULL | 30793 | 0 | 0 | | 344 | readonly | localhost:39314 | NULL | Connect | 31 | Waiting in connection\_control plugin | NULL | 30706 | 0 | 0 | | 345 | readonly | localhost:39318 | NULL | Connect | 31 | Waiting in connection\_control plugin | NULL | 30620 | 0 | 0 | | 346 | readonly | localhost:39322 | NULL | Connect | 30 | Waiting in connection\_control plugin | NULL | 30595 | 0 | 0 | | 347 | readonly | localhost:39326 | NULL | Connect | 30 | Waiting in connection\_control plugin | NULL | 30464 | 0 | 0 | | 348 | readonly | localhost:39330 | NULL | Connect | 30 | Waiting in connection\_control plugin | NULL | 30321 | 0 | 0 | | 349 | readonly | localhost:39334 | NULL | Connect | 30 | Waiting in connection\_control plugin | NULL | 30253 | 0 | 0 | | 356 | mberry | localhost:39412 | NULL | Query | 0 | init | show processlist | 0 | 0 | 0 | | 357 | readonly | localhost:39432 | NULL | Connect | 1 | Waiting in connection\_control plugin | NULL | 823 | 0 | 0 | | 358 | readonly | localhost:39436 | NULL | Connect | 1 | Waiting in connection\_control plugin | NULL | 736 | 0 | 0 | | 359 | readonly | localhost:39440 | NULL | Connect | 1 | Waiting in connection\_control plugin | NULL | 670 | 0 | 0 | | 360 | readonly | localhost:39444 | NULL | Connect | 0 | Waiting in connection\_control plugin | NULL | 522 | 0 | 0 | | 361 | readonly | localhost:39448 | NULL | Connect | 0 | Waiting in connection\_control plugin | NULL | 406 | 0 | 0 | | 362 | readonly | localhost:39452 | NULL | Connect | 0 | Waiting in connection\_control plugin | NULL | 258 | 0 | 0 | ±----±----------------±------------------------------------±-----±--------±-----±-------------------------------------±-----------------------------------------------------------------------------------------------------±--------±----------±--------------+ 54 rows in set (0.00 sec) ---
**Author:** ![Pep\_Pla](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/pep_pla/32/9735_2.png) [@Pep\_Pla](https://forums.percona.com/u/Pep_Pla)\ **Post date:** [February 22, 2023, 9:59pm UTC](https://forums.percona.com/t/pmm-creating-too-many-connections/20171/4 "2023-02-22T21:59:38Z")
Hi, I think the problem here is that connection is not working properly. Seems to be related to this bug report: [https://bugs.mysql.com/bug.php?id=89155](https://bugs.mysql.com/bug.php?id=89155) More information here: [https://dev.mysql.com/doc/refman/8.0/en/connection-control.html](https://dev.mysql.com/doc/refman/8.0/en/connection-control.html) I recommend checking with the connection control plugin disabled. If the number of connections disappears, then probably we’re experiencing a problem with the credentials used by pmm to connect. I would verify if the agent can connect from localhost using the readonly user and the password configured in pmm. Pep