我的应用程序在Linux上作为后台进程运行。它目前在终端窗口的命令行中启动。
最近,一个用户正在执行应用程序一段时间,它神秘地死亡了。文本:
杀了
在终端机上。这样发生了两次。我问是否有人在不同的终端使用kill命令杀死进程?不。
在什么情况下Linux会决定终止我的进程?我相信shell显示“已杀”是因为进程在接收到kill(9)信号后死亡。如果Linux发送了终止信号,系统日志中是否应该有一条消息解释为什么它被终止?
我的应用程序在Linux上作为后台进程运行。它目前在终端窗口的命令行中启动。
最近,一个用户正在执行应用程序一段时间,它神秘地死亡了。文本:
杀了
在终端机上。这样发生了两次。我问是否有人在不同的终端使用kill命令杀死进程?不。
在什么情况下Linux会决定终止我的进程?我相信shell显示“已杀”是因为进程在接收到kill(9)信号后死亡。如果Linux发送了终止信号,系统日志中是否应该有一条消息解释为什么它被终止?
当前回答
像systemtap(或跟踪程序)这样的工具可以监视内核信号传输逻辑和报告。例如,https://sourceware.org/systemtap/examples/process/sigmon.stp
# stap --example sigmon.stp -x 31994 SIGKILL
SPID SNAME RPID RNAME SIGNUM SIGNAME
5609 bash 31994 find 9 SIGKILL
该脚本中的过滤if块可以根据口味进行调整,也可以取消以跟踪系统范围的信号流量。可以通过收集回溯跟踪来进一步隔离原因(分别为内核和用户空间向探针添加print_backtrace()和/或print_ubacktrace())。
其他回答
我最近遇到了这个问题。最后,我发现我的进程在自动调用Opensuse zypper更新后被杀死了。禁用zypper更新解决了我的问题。
PAM模块限制资源导致了您所描述的结果:我的进程神秘地死亡,控制台窗口上的文本为Killed。没有日志输出,无论是syslog还是kern.log。顶部程序帮助我发现,在CPU使用一分钟后,我的进程就会被杀死。
在lsf环境中(交互式或其他),如果应用程序的内存利用率超过了队列上的管理员预先设定的阈值,或者提交给队列的资源请求,那么进程将被杀死,这样其他用户就不会成为潜在运行的受害者。当它这样做时,它并不总是发送电子邮件,这取决于它的设置方式。
在这种情况下,一种解决方案是找到具有更大资源的队列,或者在提交中定义更大的资源需求。
你可能还想复习man ulimit
虽然我不记得导致了死亡,但我需要它已经有一段时间了。
这是Linux内存不足管理器(OOM)。你的进程被选中是因为“不好”——近期性、常驻大小(正在使用的内存,而不仅仅是分配的内存)和其他因素的组合。
sudo journalctl -xb
你会看到这样的消息:
Jul 20 11:05:00 someapp kernel: Mem-Info:
Jul 20 11:05:00 someapp kernel: Node 0 DMA per-cpu:
Jul 20 11:05:00 someapp kernel: CPU 0: hi: 0, btch: 1 usd: 0
Jul 20 11:05:00 someapp kernel: Node 0 DMA32 per-cpu:
Jul 20 11:05:00 someapp kernel: CPU 0: hi: 186, btch: 31 usd: 30
Jul 20 11:05:00 someapp kernel: active_anon:206043 inactive_anon:6347 isolated_anon:0
active_file:722 inactive_file:4126 isolated_file:0
unevictable:0 dirty:5 writeback:0 unstable:0
free:12202 slab_reclaimable:3849 slab_unreclaimable:14574
mapped:792 shmem:12802 pagetables:1651 bounce:0
free_cma:0
Jul 20 11:05:00 someapp kernel: Node 0 DMA free:4576kB min:708kB low:884kB high:1060kB active_anon:10012kB inactive_anon:488kB active_file:4kB inactive_file:4kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present
Jul 20 11:05:00 someapp kernel: lowmem_reserve[]: 0 968 968 968
Jul 20 11:05:00 someapp kernel: Node 0 DMA32 free:44232kB min:44344kB low:55428kB high:66516kB active_anon:814160kB inactive_anon:24900kB active_file:2884kB inactive_file:16500kB unevictable:0kB isolated(anon):0kB isolated
Jul 20 11:05:00 someapp kernel: lowmem_reserve[]: 0 0 0 0
Jul 20 11:05:00 someapp kernel: Node 0 DMA: 17*4kB (UEM) 22*8kB (UEM) 15*16kB (UEM) 12*32kB (UEM) 8*64kB (E) 9*128kB (UEM) 2*256kB (UE) 3*512kB (UM) 0*1024kB 0*2048kB 0*4096kB = 4580kB
Jul 20 11:05:00 someapp kernel: Node 0 DMA32: 216*4kB (UE) 601*8kB (UE) 448*16kB (UE) 311*32kB (UEM) 135*64kB (UEM) 74*128kB (UEM) 5*256kB (EM) 0*512kB 0*1024kB 1*2048kB (R) 0*4096kB = 44232kB
Jul 20 11:05:00 someapp kernel: Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
Jul 20 11:05:00 someapp kernel: 17656 total pagecache pages
Jul 20 11:05:00 someapp kernel: 0 pages in swap cache
Jul 20 11:05:00 someapp kernel: Swap cache stats: add 0, delete 0, find 0/0
Jul 20 11:05:00 someapp kernel: Free swap = 0kB
Jul 20 11:05:00 someapp kernel: Total swap = 0kB
Jul 20 11:05:00 someapp kernel: 262141 pages RAM
Jul 20 11:05:00 someapp kernel: 7645 pages reserved
Jul 20 11:05:00 someapp kernel: 264073 pages shared
Jul 20 11:05:00 someapp kernel: 240240 pages non-shared
Jul 20 11:05:00 someapp kernel: [ pid ] uid tgid total_vm rss nr_ptes swapents oom_score_adj name
Jul 20 11:05:00 someapp kernel: [ 241] 0 241 13581 1610 26 0 0 systemd-journal
Jul 20 11:05:00 someapp kernel: [ 246] 0 246 10494 133 22 0 -1000 systemd-udevd
Jul 20 11:05:00 someapp kernel: [ 264] 0 264 29174 121 26 0 -1000 auditd
Jul 20 11:05:00 someapp kernel: [ 342] 0 342 94449 466 67 0 0 NetworkManager
Jul 20 11:05:00 someapp kernel: [ 346] 0 346 137495 3125 88 0 0 tuned
Jul 20 11:05:00 someapp kernel: [ 348] 0 348 79595 726 60 0 0 rsyslogd
Jul 20 11:05:00 someapp kernel: [ 353] 70 353 6986 72 19 0 0 avahi-daemon
Jul 20 11:05:00 someapp kernel: [ 362] 70 362 6986 58 18 0 0 avahi-daemon
Jul 20 11:05:00 someapp kernel: [ 378] 0 378 1621 25 8 0 0 iprinit
Jul 20 11:05:00 someapp kernel: [ 380] 0 380 1621 26 9 0 0 iprupdate
Jul 20 11:05:00 someapp kernel: [ 384] 81 384 6676 142 18 0 -900 dbus-daemon
Jul 20 11:05:00 someapp kernel: [ 385] 0 385 8671 83 21 0 0 systemd-logind
Jul 20 11:05:00 someapp kernel: [ 386] 0 386 31573 153 15 0 0 crond
Jul 20 11:05:00 someapp kernel: [ 391] 999 391 128531 2440 48 0 0 polkitd
Jul 20 11:05:00 someapp kernel: [ 400] 0 400 9781 23 8 0 0 iprdump
Jul 20 11:05:00 someapp kernel: [ 419] 0 419 27501 32 10 0 0 agetty
Jul 20 11:05:00 someapp kernel: [ 855] 0 855 22883 258 43 0 0 master
Jul 20 11:05:00 someapp kernel: [ 862] 89 862 22926 254 44 0 0 qmgr
Jul 20 11:05:00 someapp kernel: [23631] 0 23631 20698 211 43 0 -1000 sshd
Jul 20 11:05:00 someapp kernel: [12884] 0 12884 81885 3754 80 0 0 firewalld
Jul 20 11:05:00 someapp kernel: [18130] 0 18130 33359 291 65 0 0 sshd
Jul 20 11:05:00 someapp kernel: [18132] 1000 18132 33791 748 64 0 0 sshd
Jul 20 11:05:00 someapp kernel: [18133] 1000 18133 28867 122 13 0 0 bash
Jul 20 11:05:00 someapp kernel: [18428] 99 18428 208627 42909 151 0 0 node
Jul 20 11:05:00 someapp kernel: [18486] 89 18486 22909 250 46 0 0 pickup
Jul 20 11:05:00 someapp kernel: [18515] 1000 18515 352905 141851 470 0 0 npm
Jul 20 11:05:00 someapp kernel: [18520] 0 18520 33359 291 66 0 0 sshd
Jul 20 11:05:00 someapp kernel: [18522] 1000 18522 33359 294 64 0 0 sshd
Jul 20 11:05:00 someapp kernel: [18523] 1000 18523 28866 115 12 0 0 bash
Jul 20 11:05:00 someapp kernel: Out of memory: Kill process 18515 (npm) score 559 or sacrifice child
Jul 20 11:05:00 someapp kernel: Killed process 18515 (npm) total-vm:1411620kB, anon-rss:567404kB, file-rss:0kB
这看起来是一篇关于这个主题的好文章:驯服OOM杀手(1)。
The gist is that Linux overcommits memory. When a process asks for more space, Linux will give it that space, even if it is claimed by another process, under the assumption that nobody actually uses all of the memory they ask for. The process will get exclusive use of the memory it has allocated when it actually uses it, not when it asks for it. This makes allocation quick, and might allow you to "cheat" and allocate more memory than you really have. However, once processes start using this memory, Linux might realize that it has been too generous in allocating memory it doesn't have, and will have to kill off a process to free some up. The process to be killed is based on a score taking into account runtime (long-running processes are safer), memory usage (greedy processes are less safe), and a few other factors, including a value you can adjust to make a process less likely to be killed. It's all described in the article in a lot more detail.
编辑:下面是[另一篇文章](2),它很好地解释了如何选择进程(带有一些内核代码示例的注释)。它的优点在于,它包含了一些关于各种bad()规则背后原因的注释。