kernel: Out of Memory: Killed process
 

Hi.

Using Fedora Core 2:
Linux myserver.com 2.6.9-1.667 #1 Tue Nov 2 14:41:25 EST 2004 i686 i686 i386 GNU/Linux

I've got installed 'Apache 2.0.52' and 'MySQL 4.1.9'.

I've noticed this morning MySQL daemon was stopped and I've read '/var/log/messages':
Aug 12 02:07:03 myserver kernel: Out of Memory: Killed process 547 (mysqld).
Aug 12 02:17:15 myserver kernel: Out of Memory: Killed process 548 (mysqld).
Aug 12 02:21:00 myserver kernel: Out of Memory: Killed process 549 (mysqld).
Aug 12 02:21:52 myserver kernel: Out of Memory: Killed process 550 (mysqld).
Aug 12 02:22:38 myserver kernel: Out of Memory: Killed process 551 (mysqld).
Aug 12 02:23:59 myserver kernel: Out of Memory: Killed process 552 (mysqld).
Aug 12 02:25:54 myserver kernel: Out of Memory: Killed process 553 (mysqld).


[]# top
Tasks: 107 total, 2 running, 105 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0% us, 0.3% sy, 0.0% ni, 99.7% id, 0.0% wa, 0.0% hi, 0.0% si
Mem: 508072k total, 479852k used, 28220k free, 96616k buffers
Swap: 1084376k total, 21492k used, 1062884k free, 65044k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
26112 mysql 16 0 71680 25m 6172 S 0.0 5.1 0:00.19 mysqld
26113 mysql 16 0 71680 25m 6172 S 0.0 5.1 0:00.11 mysqld
26114 mysql 20 0 71680 25m 6172 S 0.0 5.1 0:00.00 mysqld
26115 mysql 16 0 71680 25m 6172 S 0.0 5.1 0:00.00 mysqld
26116 mysql 16 0 71680 25m 6172 S 0.0 5.1 0:00.00 mysqld
26117 mysql 20 0 71680 25m 6172 S 0.0 5.1 0:00.00 mysqld
26118 mysql 16 0 71680 25m 6172 S 0.0 5.1 0:00.00 mysqld
26119 mysql 16 0 71680 25m 6172 S 0.0 5.1 0:00.00 mysqld
26120 mysql 16 0 71680 25m 6172 S 0.0 5.1 0:00.00 mysqld
26121 mysql 16 0 71680 25m 6172 S 0.0 5.1 0:00.01 mysqld
26847 mysql 16 0 71680 25m 6172 S 0.0 5.1 0:00.00 mysqld
26595 apache 15 0 33028 23m 16m S 0.0 4.8 0:03.80 httpd
26271 apache 15 0 33108 23m 16m S 0.0 4.8 0:07.40 httpd
26043 apache 16 0 32724 23m 16m S 0.0 4.7 0:09.06 httpd
26040 apache 15 0 32748 23m 16m S 0.0 4.7 0:09.67 httpd
26045 apache 15 0 32688 23m 16m S 0.0 4.7 0:08.92 httpd
26338 apache 15 0 32440 23m 16m S 0.0 4.7 0:08.33 httpd
26046 apache 15 0 32576 23m 16m S 0.0 4.7 0:08.74 httpd
26039 apache 15 0 32372 23m 16m S 0.0 4.7 0:08.66 httpd
26143 apache 16 0 32456 23m 16m S 0.0 4.7 0:08.46 httpd
26360 apache 16 0 32652 23m 16m S 0.0 4.6 0:06.18 httpd
26041 apache 16 0 32440 23m 16m S 0.0 4.6 0:10.75 httpd
26044 apache 15 0 32420 22m 16m S 0.0 4.6 0:10.25 httpd
26042 apache 15 0 32432 22m 16m S 0.0 4.6 0:09.26 httpd
26394 apache 15 0 32380 22m 16m S 0.0 4.6 0:05.22 httpd
27025 apache 15 0 31420 21m 16m S 0.0 4.4 0:02.16 httpd

[]# cat /proc/meminfo
MemTotal: 508072 kB
MemFree: 72428 kB
Buffers: 37392 kB
Cached: 99080 kB
SwapCached: 18292 kB
Active: 326536 kB
Inactive: 80968 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 508072 kB
LowFree: 72428 kB
SwapTotal: 1084376 kB
SwapFree: 1058176 kB
Dirty: 84 kB
Writeback: 0 kB
Mapped: 269244 kB
Slab: 22948 kB
Committed_AS: 496572 kB
PageTables: 2256 kB
VmallocTotal: 3620856 kB
VmallocUsed: 2484 kB
VmallocChunk: 3617784 kB
HugePages_Total: 0
HugePages_Free: 0
Hugepagesize: 4096 kB


I've got some doubts:
1) Why are there 11 mysqld proccesses?
2) Why are there 15 httpd proccesses?
3) How can avoid this issue?

Thank you very much.

I am very much a mysql newbie but came across this recently while setting up queries and found that this can be caused by failing to close the connection after a query. If you are using php then you need to check that that the connection to the database is being closed else the queries stay open and uses all the memory.