Apache strace to hunt down a memory leak
- by Zipp
We have a server with a memory issue: the server keeps allocating itself memory and doesn't release it. We're running Apache. I set MaxReqsPerClient to a really low value just so the threads don't hold a lot of memory, but has anyone seen calls like this? Am I wrong in thinking that it's probably Drupal pulling too much data back from the cache in DB?
read(52, "h_index\";a:2:{s:6:\"weight\";i:1;s"..., 6171) = 1368
read(52, "\";a:2:{s:6:\"author\";a:3:{s:5:\"la"..., 4803) = 1368
read(52, ":\"description\";s:19:\"Term name t"..., 3435) = 1368
read(52, "abel\";s:4:\"Name\";s:11:\"descripti"..., 2067) = 1368
read(52, "ions\";a:2:{s:4:\"form\";a:3:{s:4:\""..., 16384) = 708
brk(0x2ab554396000) = 0x2ab5542f5000
mmap(NULL, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2ab55f653000
brk(0x2ab554356000) = 0x2ab5542f5000
mmap(NULL, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2ab55f753000
brk(0x2ab554356000) = 0x2ab5542f5000
mmap(NULL, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2ab55f853000
brk(0x2ab554356000) = 0x2ab5542f5000
mmap(NULL, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2ab55f953000
brk(0x2ab554356000) = 0x2ab5542f5000
mmap(NULL, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2ab55fa53000
brk(0x2ab554356000) = 0x2ab5542f5000
mmap(NULL, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2ab55fb53000
brk(0x2ab554356000) = 0x2ab5542f5000
mmap(NULL, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2ab55fc53000
poll([{fd=52, events=POLLIN|POLLPRI}], 1, 0) = 0 (Timeout)
write(52, "d\0\0\0\3SELECT cid, data, created, "..., 104) = 104
read(52, "\1\0\0\1\5E\0\0\2\3def\23drupal_database_nam"..., 16384) = 1368
read(52, ";s:11:\"granularity\";a:5:{s:4:\"ye"..., 34783) = 1368
read(52, ":4:\"date\";}s:9:\"datestamp\";a:9:{"..., 33415) = 1368
read(52, "\";i:0;s:15:\"display_default\";i:0"..., 32047) = 1368
read(52, "e as an integer value.\";s:8:\"set"..., 30679) = 1368
read(52, "label' pairs, i.e. 'Fraction': 0"..., 29311) = 1368
top (the procs just keep growing in memory..):
12845 apache 15 0 581m 246m 37m S 0.0 4.1 0:17.39 httpd
12846 apache 15 0 571m 235m 37m S 0.0 4.0 0:12.13 httpd
12833 apache 15 0 420m 117m 37m S 0.0 2.0 0:06.04 httpd
12851 apache 15 0 412m 113m 37m S 0.0 1.9 0:05.32 httpd
13871 apache 15 0 409m 109m 37m S 0.0 1.8 0:04.90 httpd
12844 apache 15 0 407m 108m 37m S 0.0 1.8 0:04.50 httpd
13870 apache 15 0 407m 108m 37m S 0.3 1.8 0:03.50 httpd
14903 apache 15 0 402m 103m 37m S 0.3 1.7 0:01.29 httpd
14850 apache 15 0 397m 100m 37m S 0.0 1.7 0:02.08 httpd
14907 apache 15 0 390m 93m 36m S 0.0 1.6 0:01.32 httpd
13872 apache 15 0 386m 91m 37m S 0.0 1.5 0:03.13 httpd
12843 apache 15 0 373m 81m 37m S 0.0 1.4 0:02.51 httpd
14901 apache 15 0 370m 75m 33m S 0.0 1.3 0:00.78 httpd
14904 apache 15 0 335m 29m 15m S 0.0 0.5 0:00.26 httpd