Apache2 Outperforming lighttpd 1.5

Here's an output of top on my VPS running Ubuntu 10.04. The first output is while a server was running Apache2 (and lighttpd on a secondary port). The Apache2 instances were under heavy stress testing at the time, and their total CPU was 30.2%. In the second output, lighttpd had taken over as the main server instance (Apache2 was completely disabled). In this scenario, lighttpd was under no load and is using 46.2% CPU (those php-cgi processes are part of lighttpd). Memory usage is counted and doubled, since the VPS is telling the OS that it has twice the RAM available.

I must be doing my math wrong or something; Isn't lighttpd supposed to be the more efficient of the two servers?

top - 21:00:13 up 47 days, 21:08,  1 user,  load average: 0.33, 0.15, 0.05
Tasks:  30 total,   1 running,  29 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.8%us,  0.2%sy,  0.0%ni, 98.9%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:    946344k total,   505324k used,   441020k free,        0k buffers
Swap:        0k total,        0k used,        0k free,        0k cached

 PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
17925 www-data  15   0  195m  11m 5816 S    3  1.3   0:01.49 apache2
14217 www-data  15   0  195m  11m 5816 S    2  1.2   0:01.44 apache2
19854 www-data  15   0  195m  11m 5816 S    2  1.3   0:01.39 apache2
30485 www-data  15   0  195m  12m 6704 S    2  1.4   0:01.68 apache2
30540 www-data  15   0  195m  11m 6064 S    2  1.3   0:01.69 apache2
14215 www-data  15   0  195m  11m 5816 S    1  1.3   0:01.40 apache2
19855 www-data  15   0  195m  11m 5972 S    1  1.3   0:01.36 apache2
30515 www-data  15   0  195m  11m 5864 S    1  1.3   0:01.68 apache2
30495 www-data  15   0  195m  11m 5852 S    1  1.3   0:01.67 apache2
30532 www-data  15   0  195m  11m 5824 S    1  1.3   0:01.82 apache2
12190 www-data  15   0  195m  11m 5812 S    1  1.2   0:01.69 apache2
 9641 mysql     18   0  307m  32m 7816 S    0  3.5   1:40.80 mysqld
 9787 nobody    18   0  149m  13m  916 S    0  1.5   0:12.37 memcached
 1 root      15   0 23308 1560 1264 S    0  0.2   0:03.15 init
 3982 root      15   0 18008 2120 1492 S    0  0.2   0:00.29 bash
 9678 root      15   0 21072 1012  776 S    0  0.1   0:11.93 cron
 9752 root      15   0 70608 3212 2484 S    0  0.3   0:00.05 sshd
 9771 syslog    15   0 12444  796  604 S    0  0.1   0:10.71 syslogd
 9829 root      18   0 49256 1084  540 S    0  0.1   1:37.00 sshd
 9873 root      15   0 69512 2452  780 S    0  0.3   0:11.83 sendmail-mta
 9958 www-data  25   0  122m 7396 4480 S    0  0.8   0:00.01 php-cgi
 9977 www-data  15   0  123m  10m 6060 S    0  1.1   0:06.17 php-cgi
 9981 www-data  15   0  125m  18m  11m S    0  2.0   0:06.65 php-cgi
 9982 www-data  15   0  124m  12m 8520 S    0  1.4   0:06.30 php-cgi
 9984 www-data  15   0  124m  14m  10m S    0  1.6   0:06.26 php-cgi
23562 root      15   0 19084 1328 1060 R    0  0.1   0:00.04 top
25949 tlhunter  15   0 70608 1796 1032 S    0  0.2   0:01.12 sshd
26144 tlhunter  18   0 17856 1920 1444 S    0  0.2   0:00.00 bash
30255 root      16   0 35580 1272  972 S    0  0.1   0:00.02 su
30406 root      18   0  193m 8508 3980 S    0  0.9   0:00.07 apache2

30.2% belongs to apache (doubled since the VPS doubles our reported max RAM)

top - 22:47:45 up 2 days, 9 min,  1 user,  load average: 0.06, 0.01, 0.00
Tasks:  24 total,   1 running,  23 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,   415264k used,   531080k 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 23308 1552 1260 S    0  0.2   0:00.37 init
 7182 tlhunter  18   0 70608 1668  944 S    0  0.2   0:00.00 sshd
 7302 tlhunter  16   0 17856 1920 1444 S    0  0.2   0:00.00 bash
11438 root      16   0 35580 1268  972 S    0  0.1   0:00.01 su
13622 www-data  18   0 91568 2992  908 S    0  0.3   0:01.07 lighttpd
13625 www-data  23   0  137m 7240 4364 S    0  0.8   0:00.02 php-cgi
13646 www-data  15   0  143m  18m  12m S    0  2.0   0:00.15 php-cgi
13647 www-data  15   0  144m  21m  14m S    0  2.3   0:00.38 php-cgi
13648 www-data  15   0  143m  25m  19m S    0  2.8   0:00.32 php-cgi
13649 www-data  15   0  143m  18m  12m S    0  2.0   0:00.15 php-cgi
13700 www-data  20   0  137m 7236 4364 S    0  0.8   0:00.02 php-cgi
13730 www-data  15   0  144m  26m  19m S    0  2.8   0:04.91 php-cgi
13731 www-data  15   0  144m  28m  21m S    0  3.1   0:05.11 php-cgi
13732 www-data  15   0  144m  28m  21m S    0  3.1   0:04.92 php-cgi
13736 www-data  15   0  144m  29m  23m S    0  3.2   0:04.97 php-cgi
17557 root      18   0 18004 2052 1428 S    0  0.2   0:00.00 bash
20168 root      16   0 70608 3204 2484 S    0  0.3   0:00.03 sshd
22281 root      18   0 19084 1320 1064 R    0  0.1   0:00.00 top
28592 mysql     17   0  177m  30m 7572 S    0  3.3   0:04.26 mysqld
29985 root      18   0 21072 1012  772 S    0  0.1   0:00.50 cron
30127 root      15   0 49256 1084  540 S    0  0.1   0:00.01 sshd
30362 syslog    15   0 12444  796  604 S    0  0.1   0:00.11 syslogd
30469 nobody    18   0 81428 9644  872 S    0  1.0   0:00.43 memcached
32607 root      18   0 69512 2412  744 S    0  0.3   0:00.71 sendmail-mta

46.4% belongs to lighttpd (doubled since the VPS doubles our reported max RAM)
Thomas Hunter II Avatar

Thomas is the author of Advanced Microservices and is a prolific public speaker with a passion for reducing complex problems into simple language and diagrams. His career includes working at Fortune 50's in the Midwest, co-founding a successful startup, and everything in between.