# mysqld dies with semaphore wait **URL:** \ **Category:** PMM 1.x\ **Created:** [March 4, 2019, 3:16pm UTC](https://forums.percona.com/t/mysqld-dies-with-semaphore-wait/6884 "2019-03-04T15:16:28Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![jerm](https://avatars.discourse-cdn.com/v4/letter/j/d26b3c/32.png) [@jerm](https://forums.percona.com/u/jerm)\ **Post date:** [March 4, 2019, 3:16pm UTC](https://forums.percona.com/t/mysqld-dies-with-semaphore-wait/6884/1 "2019-03-04T15:16:28Z")
Dear Sirs and Ma’ams, Thank you for your work on PMM. I am using it in AWS to monitor RDS instances. It has been mostly working great, except for in our production environment. There we are running 1.17 in a docker on a t2.large instance with a gp2 ebs volume monitoring 8 rds instances. Everything starts out fine, but a few days or so into the docker running, mysqld dies in the container. At this point, the graphs work, but the Query Analytics stop. Please find attached the the output from mysql.log Thanks, Jerm InnoDB: ###### Diagnostic info printed to the standard error stream InnoDB: Error: semaphore wait has lasted \> 600 seconds InnoDB: We intentionally crash the server, because it appears to be hung. 190304 5:49:54 InnoDB: Assertion failure in thread 140219024246528 in file srv0srv.c line 2980 InnoDB: We intentionally generate a memory trap. InnoDB: Submit a detailed bug report to [http://bugs.mysql.com](http://bugs.mysql.com). InnoDB: If you get repeated assertion failures or crashes, even InnoDB: immediately after the mysqld startup, there may be InnoDB: corruption in the InnoDB tablespace. Please refer to InnoDB: [url][http://dev.mysql.com/doc/refman/5.5/en/forcing-innodb-recovery.html[/url]](http://dev.mysql.com/doc/refman/5.5/en/forcing-innodb-recovery.html%5B/url%5D) InnoDB: about forcing recovery. 05:49:54 UTC - mysqld got signal 6 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. Please help us make Percona Server better by reporting any bugs at [url][System Dashboard - Percona JIRA](http://bugs.percona.com/%5B/url%5D) key\_buffer\_size=8388608 read\_buffer\_size=131072 max\_used\_connections=61 max\_threads=514 thread\_count=58 connection\_count=58 It is possible that mysqld could use up to key\_buffer\_size + (read\_buffer\_size + sort\_buffer\_size)\*max\_threads = 1133032 K bytes of memory Hope that’s ok; if not, decrease some variables in the equation. Thread pointer: 0x0 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong… stack\_bottom = 0 thread\_stack 0x40000 /usr/sbin/mysqld(my\_print\_stacktrace+0x3b)[0x7debfb] /usr/sbin/mysqld(handle\_fatal\_signal+0x4b1)[0x6a5471] /lib64/libpthread.so.0(+0xf6d0)[0x7f875f9956d0] /lib64/libc.so.6(gsignal+0x37)[0x7f875e0c0277] /lib64/libc.so.6(abort+0x148)[0x7f875e0c1968] /usr/sbin/mysqld[0x83afd5] /lib64/libpthread.so.0(+0x7e25)[0x7f875f98de25] /lib64/libc.so.6(clone+0x6d)[0x7f875e188bad] You may download the Percona Server operations manual by visiting [url][http://www.percona.com/software/percona-server/[/url]](http://www.percona.com/software/percona-server/%5B/url%5D). You may find information in the manual which will help you identify the cause of the crash. ---
**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:** [March 14, 2019, 6:47pm UTC](https://forums.percona.com/t/mysqld-dies-with-semaphore-wait/6884/2 "2019-03-14T18:47:56Z")
Hi [jerm](https://percona.vanillacommunities.com/profile/x/x/42719) It appears you have a crashing MySQL instance you can try to take action to save the installation, for this advice I would encourage you to head over to the Percona forums related to support of Percona Server for MySQL: [URL][https://www.percona.com/forums/questions-discussions/mysql-and-percona-server[/URL]](https://www.percona.com/forums/questions-discussions/mysql-and-percona-server%5B/URL%5D) If you can post this as a case related to Percona Server crashing we’ll then get more eyes on the issue and bring some sort of actions together to eliminate the crashing condition. I suggest as part of your post that you share the System Overview dashboard for a period spanning crashes, using the pmm-server identifier. Here’s an example: [URL=“[Grafana](https://pmmdemo.percona.com/graph/d/qyzrQGHmk/system-overview?from=now-7d&to=now&refresh=1m&orgId=1&var-interval=%24__auto_interval_interval&var-host=pmm-server)”][Grafana](https://pmmdemo.percona.com/graph/d/qyzrQGHmk/system-overview?from=now-7d&to=now&refresh=1m&orgId=1&var-interval=%24__auto_interval_interval&var-host=pmm-server%5B/URL%5D) I hope this helps