Por que meu servidor congela todos os dias ao mesmo tempo?

Question

Meu servidor congela todos os dias às 00:50. Eu não sei o que pode ser. Nos arquivos de log, encontrei apenas uma listagem suspeita, mas não sei o que isso significa. Alguém poderia me ajudar ??

kernel: php5-cgi invoked oom-killer: gfp_mask=0x84d0, order=0, oom_adj=0, oom_score_adj=0
kernel: php5-cgi cpuset=/ mems_allowed=0
kernel: Pid: 20316, comm: php5-cgi Not tainted 2.6.38.2-xxxx-std-ipv6-64 #2
kernel: Call Trace:
kernel: [<ffffffff810de9e8>] ? dump_header+0x88/0x1d0
kernel: [<ffffffff810aa6e3>] ? ktime_get_ts+0xb3/0xe0
kernel: [<ffffffff810de931>] ? oom_unkillable_task+0x91/0xc0
kernel: [<ffffffff8150c7e5>] ? ___ratelimit+0xa5/0x120
kernel: [<ffffffff810def0c>] ? oom_kill_process+0x8c/0x2e0
kernel: [<ffffffff810dedd3>] ? select_bad_process+0x93/0x140
kernel: [<ffffffff810df398>] ? out_of_memory+0x238/0x3e0
kernel: [<ffffffff810e45bd>] ? __alloc_pages_nodemask+0x86d/0x8a0
kernel: [<ffffffff8110ff4a>] ? alloc_pages_current+0xaa/0x120
kernel: [<ffffffff81069d46>] ? pte_alloc_one+0x16/0x40
kernel: [<ffffffff810fa159>] ? __pte_alloc+0x29/0xd0
kernel: [<ffffffff810fa363>] ? handle_mm_fault+0x163/0x200
kernel: [<ffffffff81066077>] ? do_page_fault+0x197/0x410
kernel: [<ffffffff81100556>] ? do_brk+0x286/0x390
kernel: [<ffffffff81a7419f>] ? page_fault+0x1f/0x30
kernel: Mem-Info:
kernel: Node 0 DMA per-cpu:
kernel: CPU    0: hi:    0, btch:   1 usd:   0
kernel: Node 0 DMA32 per-cpu:
kernel: CPU    0: hi:  186, btch:  31 usd: 156
kernel: active_anon:468626 inactive_anon:383 isolated_anon:0
kernel: active_file:66 inactive_file:101 isolated_file:64
kernel: unevictable:0 dirty:0 writeback:0 unstable:0
kernel: free:3426 slab_reclaimable:1691 slab_unreclaimable:13557
kernel: mapped:380 shmem:404 pagetables:10150 bounce:0
kernel: Node 0 DMA free:7932kB min:44kB low:52kB high:64kB active_anon:7056kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15684kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:388kB kernel_stack:16kB pagetables:488kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no 
 kernel: lowmem_reserve[]: 0 1967 1967 1967
kernel: Node 0 DMA32 free:5772kB min:5648kB low:7060kB high:8472kB active_anon:1867448kB inactive_anon:1532kB active_file:264kB inactive_file:404kB unevictable:0kB isolated(anon):0kB isolated(file):256kB present:2014316kB mlocked:0kB dirty:0kB writeback:0kB mapped:1520kB shmem:1616kB slab_reclaimable:6764kB slab_unreclaimable:53840kB kernel_stack:1912kB pagetables:40112kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:1423 all_unreclaimable? no
kernel: lowmem_reserve[]: 0 0 0 0
kernel: Node 0 DMA: 45*4kB 56*8kB 29*16kB 8*32kB 7*64kB 4*128kB 2*256kB 0*512kB 1*1024kB 0*2048kB 1*4096kB = 7940kB
kernel: Node 0 DMA32: 149*4kB 1*8kB 1*16kB 1*32kB 0*64kB 0*128kB 0*256kB 0*512kB 1*1024kB 0*2048kB 1*4096kB = 5772kB
kernel: 646 total pagecache pages
kernel: 0 pages in swap cache
kernel: Swap cache stats: add 0, delete 0, find 0/0
kernel: Free swap  = 0kB
kernel: Total swap = 0kB
kernel: 515824 pages RAM
kernel: 12393 pages reserved
kernel: 310091 pages shared
kernel: 436769 pages non-shared
kernel: [ pid ]   uid  tgid total_vm      rss cpu oom_adj oom_score_adj name
kernel: [ 1562]     0  1562     4238       40   0       0             0 upstart-udev-br
kernel: [ 1564]     0  1564     4230       74   0     -17         -1000 udevd
kernel: [ 1656]     0  1656     4229       75   0     -17         -1000 udevd
kernel: [ 1661]     0  1661     4229       73   0     -17         -1000 udevd
kernel: [ 2620]     0  2620    12328      141   0     -17         -1000 sshd
kernel: [ 2631]   101  2631    13713      221   0       0             0 rsyslogd
kernel: [ 2648]     0  2648     1532       30   0       0             0 getty
kernel: [ 2652]     0  2652     1532       29   0       0             0 getty
kernel: [ 2655]     0  2655     1532       29   0       0             0 getty
kernel: [ 2656]     0  2656     1532       29   0       0             0 getty
kernel: [ 2659]     0  2659     1532       30   0       0             0 getty
kernel: [ 2666]     0  2666     5281       65   0       0             0 cron
kernel: [ 2701]   102  2701    32660     5339   0       0             0 named
kernel: [ 2708]   104  2708    63627    11103   0       0             0 mysqld
kernel: [ 2723]     0  2723     3482       38   0       0             0 couriertcpd
kernel: [ 2725]     0  2725      980       17   0       0             0 courierlogger
kernel: [ 2735]     0  2735     3482       38   0       0             0 couriertcpd
kernel: [ 2737]     0  2737      980       17   0       0             0 courierlogger
kernel: [ 2744]     0  2744     3482       41   0       0             0 couriertcpd
kernel: [ 2747]     0  2747     1013       26   0       0             0 courierlogger
kernel: [ 2754]     0  2754     3482       38   0       0             0 couriertcpd
kernel: [ 2757]     0  2757      980       18   0       0             0 courierlogger
kernel: [ 3313] 65534  3313    15729       79   0       0             0 memcached
kernel: [ 3383]  1002  3383    12937     1590   0       0             0 sw-cp-serverd
kernel: [ 3393]     0  3393     4894       58   0       0             0 xinetd
kernel: [ 3535]  2522  3535     1027       28   0       0             0 qmail-send
kernel: [ 3536]  2022  3536     1015       26   0       0             0 splogger
kernel: [ 3537]     0  3537     1025       33   0       0             0 qmail-lspawn
kernel: [ 3538]  2521  3538     1025       17   0       0             0 qmail-rspawn
kernel: [ 3539]  2520  3539     1014       22   0       0             0 qmail-clean
kernel: [ 3621]     0  3621    68797     3424   0       0             0 apache2
kernel: [ 3622]     0  3622    40565     1745   0       0             0 apache2
kernel: [ 3922]   106  3922    40087    38746   0       0             0 drwebd.real
kernel: [ 3985]     0  3985     3163       37   0       0             0 mdadm
kernel: [ 4024]     0  4024     1532       30   0       0             0 getty
kernel: [24625]     0 24625    28299    11913   0       0             0 spamd
kernel: [24626]   110 24626    28299    11912   0       0             0 spamd
kernel: [24628]   110 24628    28299    11912   0       0             0 spamd
kernel: [12008]    33 12008    68960     3226   0       0             0 apache2
kernel: [12016]    33 12016    68946     3232   0       0             0 apache2
kernel: [12568]    33 12568    68952     3229   0       0             0 apache2
kernel: [13362]    33 13362    68933     3220   0       0             0 apache2
kernel: [16894]    33 16894    68946     3204   0       0             0 apache2
kernel: [16895]    33 16895    68902     3189   0       0             0 apache2
kernel: [18991]   106 18991    40087    38745   0       0             0 drwebd.real
kernel: [18992]   106 18992    40087    38745   0       0             0 drwebd.real
kernel: [18993]   106 18993    40087    38745   0       0             0 drwebd.real
kernel: [18994]   106 18994    40087    38745   0       0             0 drwebd.real
kernel: [19165]    33 19165    68995     3216   0       0             0 apache2
kernel: [19178]    33 19178    68947     3225   0       0             0 apache2
kernel: [19918]    33 19918    68961     3218   0       0             0 apache2

Se precisar de mais informações, escreva-me.

Domaneni

    

Answer 1

Uma solução foi relatada aqui: link

So what’s happened? The reason can be explained shortly: The Linux kernel likes to always allocate memory if applications asking for it. Per default it doesn’t really check if there is enough memory available. Given that behavior applications can allocate more memory as really is available. At some point it can definitely cause an out of memory situation. As result the OOM killer will be invoked and will kill that process:

Jun 11 11:35:21 vsrv03 kernel: [378878.356858] php-cgi invoked oom-killer: gfp_mask=0x1280d2, order=0, oomkilladj=0
Jun 11 11:36:11 vsrv03 kernel: [378878.356880] Pid: 8490, comm: php-cgi Not tainted 2.6.26-2-xen-amd64 #1

The downside of this action is that all other running processes are also affected. As result the complete VM didn’t work and needed a restart.

To fix this problem the behavior of the kernel has to be changed, so it will no longer overcommit the memory for application requests. Finally I have included those mentioned values into the /etc/sysctl.conf file, so they get automatically applied on start-up:

vm.overcommit_memory = 2
vm.overcommit_ratio = 80

(Reinicie para aplicar as alterações.)

Mais sobre supercomprometimento: link

    

Answer 2

O que acontece é simples, o porque não é (precisa de mais informações).

php5-cgi começa a usar um monte de memória naquele momento (pode ser um vazamento de memória ou um efeito colateral), tanto que o sistema ficará sem memória. Então o kernel o mata ( oom-killer é o matador de falta de memória do kernel) para manter a estabilidade do sistema.

Isso parece um VPS - é isso? Que tipo? Os erros de OOM são geralmente raros em máquinas físicas com RAM (1 GB +) suficiente e espaço de troca (pelo menos 2x RAM).