OOM-killer with Java application on Linux

Question

I have a problem with my Java application on a Linux system (version 2.6.39.2) with 500MB RAM. Every hour my application takes 1-2MB resident memory more. The application starts with 40MB of resident memory used. After 15 days, OOM-killer kills my application (see attached log).

More information:

• I haven’t set any memory limit (no Xms, Xmx, …) for my application.
• I have made a heap dump when 396MB of resident memory where used but for Memory Analysis tool, I only use 7.8MB of memory and there were no special memory leaks.

What can I do to found the source of the problem or how to ensure that my application will not be killed?

Thanks in advance for your help. Best regards.

EDIT: It is a standalone embedded application without server. The problem occurs on the deployed application on a machine (difficult to install analysis tools) but not on my development PC.

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Jun  7 06:15:41 HMI user.warn kernel: java invoked oom-killer: gfp_mask=0x201da, order=0, oom_adj=0, oom_score_adj=0
Jun  7 06:15:42 HMI user.warn kernel: Pid: 650, comm: java Not tainted 2.6.39.2 #7
Jun  7 06:15:42 HMI user.warn kernel: Call Trace:
Jun  7 06:15:42 HMI user.warn kernel:  [<c144c264>] ? printk+0xf/0x11
Jun  7 06:15:42 HMI user.warn kernel:  [<c1074eb8>] dump_header.clone.8+0x58/0x150
Jun  7 06:15:42 HMI user.warn kernel:  [<c11dd008>] ? ___ratelimit+0x78/0xf0
Jun  7 06:15:42 HMI user.warn kernel:  [<c1075121>] oom_kill_process.clone.11+0x41/0x220
Jun  7 06:15:42 HMI user.warn kernel:  [<c10376e8>] ? has_capability_noaudit+0x18/0x30
Jun  7 06:15:42 HMI user.warn kernel:  [<c1074fd5>] ? oom_badness+0x25/0x130
Jun  7 06:15:42 HMI user.warn kernel:  [<c10755ef>] out_of_memory+0x1bf/0x2a0
Jun  7 06:15:42 HMI user.warn kernel:  [<c1078b4a>] __alloc_pages_nodemask+0x5aa/0x5c0
Jun  7 06:15:42 HMI user.warn kernel:  [<c107a1cb>] __do_page_cache_readahead+0xdb/0x200
Jun  7 06:15:42 HMI user.warn kernel:  [<c1072b00>] ? wait_on_page_bit+0x90/0xa0
Jun  7 06:15:42 HMI user.warn kernel:  [<c107a539>] ra_submit+0x19/0x20
Jun  7 06:15:42 HMI user.warn kernel:  [<c1074762>] filemap_fault+0x3d2/0x3e0
Jun  7 06:15:42 HMI user.warn kernel:  [<c1086de9>] __do_fault+0x39/0x3a0
Jun  7 06:15:42 HMI user.warn kernel:  [<c1074390>] ? __lock_page_or_retry+0x50/0x50
Jun  7 06:15:42 HMI user.warn kernel:  [<c1089540>] handle_pte_fault+0x70/0x5b0
Jun  7 06:15:42 HMI user.warn kernel:  [<c1089b0f>] handle_mm_fault+0x8f/0x100
Jun  7 06:15:42 HMI user.warn kernel:  [<c101ff00>] do_page_fault+0x100/0x3d0
Jun  7 06:15:42 HMI user.warn kernel:  [<c1053e0a>] ? sys_futex+0x5a/0x100
Jun  7 06:15:42 HMI user.warn kernel:  [<c101fe00>] ? vmalloc_sync_all+0x110/0x110
Jun  7 06:15:42 HMI user.warn kernel:  [<c144ed1a>] error_code+0x5a/0x60
Jun  7 06:15:42 HMI user.warn kernel:  [<c1440000>] ? vsc_sata_init_one+0x1f6/0x278
Jun  7 06:15:42 HMI user.warn kernel:  [<c101fe00>] ? vmalloc_sync_all+0x110/0x110
Jun  7 06:15:42 HMI user.warn kernel: Mem-Info:
Jun  7 06:15:42 HMI user.warn kernel: DMA per-cpu:
Jun  7 06:15:42 HMI user.warn kernel: CPU    0: hi:    0, btch:   1 usd:   0
Jun  7 06:15:42 HMI user.warn kernel: Normal per-cpu:
Jun  7 06:15:42 HMI user.warn kernel: CPU    0: hi:  186, btch:  31 usd:  52
Jun  7 06:15:42 HMI user.warn kernel: active_anon:111882 inactive_anon:51 isolated_anon:0
Jun  7 06:15:42 HMI user.warn kernel:  active_file:70 inactive_file:853 isolated_file:0
Jun  7 06:15:42 HMI user.warn kernel:  unevictable:0 dirty:0 writeback:0 unstable:0
Jun  7 06:15:42 HMI user.warn kernel:  free:1183 slab_reclaimable:307 slab_unreclaimable:1016
Jun  7 06:15:42 HMI user.warn kernel:  mapped:149 shmem:122 pagetables:302 bounce:0
Jun  7 06:15:42 HMI user.warn kernel: DMA free:2028kB min:88kB low:108kB high:132kB active_anon:13696kB inactive_anon:0kB active_file:0kB inactive_file:72kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15800kB mlocked:0kB dirty:0kB writeback:0kB ma
Jun  7 06:15:42 HMI user.warn kernel: lowmem_reserve[]: 0 483 483 483
Jun  7 06:15:42 HMI user.warn kernel: Normal free:2704kB min:2768kB low:3460kB high:4152kB active_anon:433832kB inactive_anon:204kB active_file:280kB inactive_file:3340kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:495488kB mlocked:0kB dirty:0kB w
Jun  7 06:15:42 HMI user.warn kernel: lowmem_reserve[]: 0 0 0 0
Jun  7 06:15:42 HMI user.warn kernel: DMA: 393*4kB 7*8kB 3*16kB 1*32kB 1*64kB 2*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 2028kB
Jun  7 06:15:42 HMI user.warn kernel: Normal: 676*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 2704kB
Jun  7 06:15:42 HMI user.warn kernel: 1057 total pagecache pages
Jun  7 06:15:42 HMI user.warn kernel: 0 pages in swap cache
Jun  7 06:15:42 HMI user.warn kernel: Swap cache stats: add 0, delete 0, find 0/0
Jun  7 06:15:42 HMI user.warn kernel: Free swap  = 0kB
Jun  7 06:15:42 HMI user.warn kernel: Total swap = 0kB
Jun  7 06:15:42 HMI user.warn kernel: 128928 pages RAM
Jun  7 06:15:42 HMI user.warn kernel: 0 pages HighMem
Jun  7 06:15:42 HMI user.warn kernel: 2847 pages reserved
Jun  7 06:15:42 HMI user.warn kernel: 476 pages shared
Jun  7 06:15:42 HMI user.warn kernel: 124258 pages non-shared
Jun  7 06:15:42 HMI user.info kernel: [ pid ]   uid  tgid total_vm      rss cpu oom_adj oom_score_adj name
Jun  7 06:15:42 HMI user.info kernel: [   78]     0    78      535       77   0     -17         -1000 udevd
Jun  7 06:15:42 HMI user.info kernel: [  314]     0   314      422       17   0       0             0 zeroconf
Jun  7 06:15:42 HMI user.info kernel: [  320]     1   320      420       17   0       0             0 portmap
Jun  7 06:15:42 HMI user.info kernel: [  349]     0   349      618       22   0       0             0 rc
Jun  7 06:15:42 HMI user.info kernel: [  358]    42   358      585       38   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  362]    44   362     3139      184   0       0             0 hald
Jun  7 06:15:42 HMI user.info kernel: [  363]     0   363      805       45   0       0             0 hald-runner
Jun  7 06:15:42 HMI user.info kernel: [  374]     0   374      821       32   0       0             0 hald-addon-inpu
Jun  7 06:15:42 HMI user.info kernel: [  386]    44   386      767       35   0       0             0 hald-addon-acpi
Jun  7 06:15:42 HMI user.info kernel: [  401]     0   401      531       23   0       0             0 dropbear
Jun  7 06:15:42 HMI user.info kernel: [  406]     0   406      425       22   0       0             0 acpid
Jun  7 06:15:42 HMI user.info kernel: [  411]     0   411      617       16   0       0             0 syslogd
Jun  7 06:15:42 HMI user.info kernel: [  413]     0   413      617       18   0       0             0 klogd
Jun  7 06:15:42 HMI user.info kernel: [  422]    46   422      666       48   0       0             0 avahi-daemon
Jun  7 06:15:42 HMI user.info kernel: [  423]    46   423      666       42   0       0             0 avahi-daemon
Jun  7 06:15:42 HMI user.info kernel: [  431]     0   431      886       18   0       0             0 pure-ftpd
Jun  7 06:15:42 HMI user.info kernel: [  442]     0   442      618       16   0       0             0 S97x11Dm
Jun  7 06:15:42 HMI user.info kernel: [  443]     0   443      741       26   0       0             0 xinit
Jun  7 06:15:42 HMI user.info kernel: [  445]     0   445     7850     4035   0       0             0 X
Jun  7 06:15:42 HMI user.info kernel: [  452]     0   452      617       15   0       0             0 sh
Jun  7 06:15:42 HMI user.info kernel: [  453]     0   453     2008      226   0       0             0 matchbox-window
Jun  7 06:15:42 HMI user.info kernel: [  454]     0   454     2001      725   0       0             0 matchbox-deskto
Jun  7 06:15:42 HMI user.info kernel: [  455]     0   455     1479      183   0       0             0 matchbox-panel
Jun  7 06:15:42 HMI user.info kernel: [  472]     0   472      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  474]     0   474   154396   104395   0       0             0 java
Jun  7 06:15:42 HMI user.info kernel: [  479]     0   479      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  484]     0   484      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  489]     0   489      585       36   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  496]     0   496      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  504]     0   504      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  509]     0   509      585       34   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  514]     0   514      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  519]     0   519      585       36   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  524]     0   524      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  529]     0   529      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  535]     0   535      585       34   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  540]     0   540      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  546]     0   546      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  552]     0   552      585       36   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  557]     0   557      585       36   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  562]     0   562      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  567]     0   567      585       34   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  572]     0   572      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  577]     0   577      585       36   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  582]     0   582      585       34   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  587]     0   587      585       34   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  592]     0   592      585       34   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  597]     0   597      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  602]     0   602      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  610]     0   610      585       34   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  616]     0   616      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  621]     0   621      585       34   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  626]     0   626      585       34   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  631]     0   631      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  636]     0   636      585       35   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  641]     0   641      585       34   0       0             0 dbus-daemon
Jun  7 06:15:42 HMI user.info kernel: [  642]     0   642     1407      155   0       0             0 mb-applet-menu-
Jun  7 06:15:42 HMI user.info kernel: [  649]     0   649     1397      139   0       0             0 mb-applet-clock
Jun  7 06:15:42 HMI user.info kernel: [  837]     0   837      530       77   0     -17         -1000 udevd
Jun  7 06:15:42 HMI user.info kernel: [  838]     0   838      532       78   0     -17         -1000 udevd
Jun  7 06:15:42 HMI user.err kernel: Out of memory: Kill process 474 (java) score 798 or sacrifice child
Jun  7 06:15:42 HMI user.err kernel: Killed process 474 (java) total-vm:617584kB, anon-rss:417580kB, file-rss:0kB

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Answer 1

So you're leaking memory and would like to know why and where.

A few things you can do

• use garbage collection logging with all the verbose options
• use the jdk tools (jmap with the histo option shows you which classes have how many instances alive etc)
• jkd tools #2 jvisualvm - on of the best free tools around
• there are free versions of commercial tools like appdynamics lite/ jxinsight opus
• use -XX:+HeapDumpOnOutOfMemoryError and analyse the heap dump once you get the OOM
• a code review can't do harm either - most likely you're not letting go of information you don't need any more

Answer 2

You probably have a memory leak. I suggest you to use a profiler tool (JProfiler is the best in my opinion) to find it. If your server doesn't have GUI you can set up the profiler remotely and use an agent on the Linux machine.