my server is at a very high memory usage constantly – to the point that it won't let me log in via ssh some times. I have to reboot the server before I can log in and when it's restarted the memory drops to ~90% usage and slowly works it's way up to ~190%.
I've noticed that restarting apache also puts me back to 90% and I can slowly watch the memory rise using hosting tools. I've been watching top, but i'm not sure what to look for. I'm pretty sure the culprit is apache, but I'm not sure why.
top at 130%
top - 08:14:59 up 49 min, 1 user, load average: 0.04, 0.01, 0.00
Tasks: 41 total, 1 running, 40 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 946344k total, 724484k used, 221860k free, 0k buffers
Swap: 0k total, 0k used, 0k free, 0k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1 root 15 0 23456 1664 1276 S 0 0.2 0:01.82 init
1173 messageb 16 0 23436 920 612 S 0 0.1 0:00.01 dbus-daemon
1222 root 15 0 49272 1088 540 S 0 0.1 0:00.02 sshd
1237 root 18 0 27128 1800 1428 S 0 0.2 0:00.00 vsftpd
1245 root 18 0 21088 1020 780 S 0 0.1 0:00.00 cron
1249 mysql 15 0 178m 36m 7356 S 0 4.0 0:01.26 mysqld
1285 syslog 18 0 12460 804 612 S 0 0.1 0:00.00 syslogd
1305 bind 18 0 286m 26m 2056 S 0 2.8 0:00.02 named
1328 root 21 0 6292 500 392 S 0 0.1 0:00.00 courierlogger
1329 root 18 0 18788 812 652 S 0 0.1 0:00.00 authdaemond
1339 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
1340 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
1341 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
1341 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
1342 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
1343 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
1426 root 15 0 37216 2276 1784 S 0 0.2 0:00.00 master
1442 postfix 18 0 39440 2236 1760 S 0 0.2 0:00.00 qmgr
1443 postfix 15 0 39280 2188 1728 S 0 0.2 0:00.00 pickup
1559 root 18 0 120m 3928 2444 S 0 0.4 0:00.06 console-kit-dae
1650 root 16 0 79148 3464 2696 S 0 0.4 0:00.03 sshd
1664 robert 17 0 79148 1744 960 S 0 0.2 0:00.01 sshd
1665 robert 16 0 12476 904 736 S 0 0.1 0:00.01 sftp-server
1666 root 16 0 79120 3516 2732 S 0 0.4 0:00.03 sshd
1680 jackson 15 0 79120 1732 932 S 0 0.2 0:00.14 sshd
1681 jackson 15 0 18032 2140 1500 S 0 0.2 0:00.04 bash
1946 root 18 0 227m 10m 4960 S 0 1.1 0:00.03 apache2
1950 www-data 15 0 270m 52m 3676 S 0 5.7 0:01.34 apache2
1951 www-data 15 0 227m 6828 1232 S 0 0.7 0:00.03 apache2
1952 www-data 15 0 227m 6828 1232 S 0 0.7 0:00.03 apache2
1960 www-data 15 0 227m 7056 1288 S 0 0.7 0:00.02 apache2
1963 www-data 15 0 271m 53m 3696 S 0 5.8 0:01.30 apache2
1964 www-data 15 0 270m 52m 3672 S 0 5.7 0:01.35 apache2
1965 www-data 15 0 270m 52m 3672 S 0 5.7 0:01.21 apache2
1968 root 16 0 79148 3468 2696 S 0 0.4 0:00.04 sshd
1982 robert 18 0 79148 1752 960 S 0 0.2 0:00.00 sshd
1983 robert 18 0 12476 924 732 S 0 0.1 0:00.00 sftp-server
1984 www-data 15 0 227m 6824 1228 S 0 0.7 0:00.02 apache2
1985 www-data 15 0 227m 6824 1228 S 0 0.7 0:00.02 apache2
1986 www-data 15 0 227m 6816 1224 S 0 0.7 0:00.00 apache2
1987 www-data 18 0 227m 5908 560 S 0 0.6 0:00.00 apache2
free -m
total used free shared buffers cached
Mem: 924 697 227 0 0 0
-/+ buffers/cache: 697 227
Swap: 0 0 0
What should I do next? Thanks for the help.
** EDIT **
top (pushed > once)
top - 09:46:06 up 2:21, 1 user, load average: 0.01, 0.03, 0.00
Tasks: 37 total, 1 running, 36 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 946344k total, 799432k used, 146912k free, 0k buffers
Swap: 0k total, 0k used, 0k free, 0k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3274 www-data 15 0 273m 54m 4756 S 0 5.9 0:02.84 apache2
2043 www-data 18 0 272m 54m 3692 S 0 5.8 0:03.65 apache2
3109 www-data 15 0 271m 53m 3748 S 0 5.8 0:05.44 apache2
3217 www-data 15 0 270m 52m 3700 S 0 5.7 0:01.46 apache2
3310 www-data 15 0 270m 52m 3672 S 0 5.7 0:01.29 apache2
2044 www-data 15 0 264m 46m 3764 S 0 5.0 0:03.20 apache2
1249 mysql 15 0 244m 38m 7348 S 0 4.2 0:03.35 mysqld
1305 bind 18 0 286m 26m 2060 S 0 2.8 0:00.02 named
2038 root 18 0 227m 10m 4960 S 0 1.1 0:00.06 apache2
3376 www-data 15 0 227m 7220 1376 S 0 0.8 0:00.00 apache2
3291 www-data 15 0 227m 7024 1376 S 0 0.7 0:00.02 apache2
3377 www-data 15 0 227m 6824 1228 S 0 0.7 0:00.00 apache2
3379 www-data 19 0 227m 5924 564 S 0 0.6 0:00.00 apache2
1559 root 18 0 120m 3928 2444 S 0 0.4 0:00.18 console-kit-dae
3358 root 16 0 79120 3508 2732 S 0 0.4 0:00.03 sshd
1650 root 15 0 79148 3476 2696 S 0 0.4 0:00.04 sshd
1426 root 15 0 37216 2276 1784 S 0 0.2 0:00.00 master
1442 postfix 15 0 39440 2236 1760 S 0 0.2 0:00.00 qmgr
3265 postfix 15 0 39280 2192 1728 S 0 0.2 0:00.00 pickup
3373 jackson 18 0 17976 2028 1448 S 0 0.2 0:00.00 bash
1664 robert 15 0 79148 1900 1060 S 0 0.2 0:00.21 sshd
1237 root 18 0 27128 1800 1428 S 0 0.2 0:00.00 vsftpd
3372 jackson 15 0 79120 1724 932 S 0 0.2 0:00.01 sshd
1 root 15 0 23456 1664 1276 S 0 0.2 0:01.82 init
3380 jackson 15 0 19100 1344 1072 R 0 0.1 0:00.06 top
1222 root 15 0 49272 1088 540 S 0 0.1 0:00.06 sshd
1245 root 18 0 21088 1020 780 S 0 0.1 0:00.00 cron
1665 robert 15 0 12476 952 736 S 0 0.1 0:00.21 sftp-server
1173 messageb 16 0 23436 920 612 S 0 0.1 0:00.02 dbus-daemon
1329 root 18 0 18788 812 652 S 0 0.1 0:00.00 authdaemond
1285 syslog 18 0 12460 804 612 S 0 0.1 0:00.00 syslogd
1328 root 21 0 6292 500 392 S 0 0.1 0:00.00 courierlogger
1339 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
1340 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
1341 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
1342 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
1343 root 18 0 18788 276 112 S 0 0.0 0:00.00 authdaemond
Best Answer
You appear to have 1GB of RAM. This is the 21st century: to borrow from another user's quip book: My cellphone has more RAM than that! -- so suggestion #1 is add more RAM. 2GB is a bare minimum, and if you're running the full LAMP stack (Linux, Apache+PHP & a database like MySQL) on one machine you really need to go with 4GB.
You also appear to have no swap - This is Bad and Wrong, so suggestion #2 is "Configure some swap space".
Unix-Like systems, including Linux, expect to be able to swap when they run out of RAM. If they run out of RAM and there's no swap space to shove stuff into they usually have a fit and stop working.
This is probably what's happening to you.
If you're on some kind of virtual/cloud system and can't add swap space you're reduced back to suggestion #1 (add enough RAM so you don't run out).
If you configured a Linux installation with no swap space you can add a swap file (here's a howto, there are others if you google around), but you're probably better off reinstalling the machine and creating an actual swap partition it's more efficient.