mysql error: Can't create a new thread (errno 11)

Question

I have a db server running Percona Xtradb server, and 5 slaves. I always get the error

mysql error: Can't create a new thread (errno 11); if you are not out of available memory, you can consult the manual for a possible OS-dependent bug

Though i set ulimited

root@master:~# ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 2062915
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 1000000
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 1000000
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited





root@master:~# cat /proc/`pidof mysqld`/limits | egrep "(processes|files)"Max processes 1000000 1000000 processes
Max open files 1000000 1000000 files

I really dont know what's going on? Please help me.

Probably the mysql thread limit is configurable thru `/etc/mysql.conf` or `/etc/my.cnf` ... — Basile Starynkevitch, Mar 29 '13 at 06:19
The maximum number of threads (processes in fact on linux) per user (or system wide) was reached when trying to create a new thread. — alk, Mar 29 '13 at 11:13
It also could be a memory issue as indicated by this bug report: http://bugs.mysql.com/bug.php?id=5656 — alk, Mar 29 '13 at 11:28
tmp_table_size = 1024M max_heap_table_size = 64M query_cache_type = 0 query_cache_size = 256M query_cache_limit = 256M max_connections = 502400 wait_timeout = 60 thread_cache_size = 100 open_files_limit = 1000000 table_definition_cache = 4096 table_open_cache = 900000 — Kevin Nguyen, Mar 29 '13 at 13:41

score 3 · Answer 1 · answered Sep 02 '13 at 23:38

3

Add a line like this to /etc/security/limits.conf

mysql  soft  nproc  4096

Then restart mysql

answered Sep 02 '13 at 23:38

Steven Lizarazo

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Can You please let me know what it did? – Faizan Younus Aug 21 '18 at 12:52
https://duntuk.com/how-raise-ulimit-open-files-and-mysql-openfileslimit Raises the upper bound on the number of files that can opened by the mysql process. – kiwicomb123 Nov 19 '21 at 22:52

score 2 · Answer 2 · edited Jan 24 '18 at 14:49

It seem that your system reach to the maximum number of thread per process, please verify status of your system about threads:

$ cat /proc/sys/kernel/threads-max

$ echo 'SHOW STATUS;' | mysql | grep -i threads

You should also review your current settings about thread_cache_size, This link may help: https://serverfault.com/questions/408845/what-value-of-thread-cache-size-should-i-use

PS: This topics should be posted in serverfault.com

mysql error: Can't create a new thread (errno 11)

2 Answers2