线上服务日志中看到 Too many open files,于是检查了一番。
一、过程
确认:进程最大打开文件数
首先确认了系统没有限制最大打开文件数,但进程的最大打开文件数是限制的:
ulimit -a
core file size (blocks, -c) unlimited
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 30007
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 655350
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 10240
cpu time (seconds, -t) unlimited
max user processes (-u) 327675
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
cat /proc/29749/limits
Limit Soft Limit Hard Limit Units
Max cpu time unlimited unlimited seconds
Max file size unlimited unlimited bytes
Max data size unlimited unlimited bytes
Max stack size 10485760 unlimited bytes
Max core file size 0 unlimited bytes
Max resident set unlimited unlimited bytes
Max processes 30007 30007 processes
Max open files 1024 1024 files
Max locked memory 65536 65536 bytes
Max address space unlimited unlimited bytes
Max file locks unlimited unlimited locks
Max pending signals 30007 30007 signals
Max msgqueue size 819200 819200 bytes
Max nice priority 0 0
Max realtime priority 0 0
Max realtime timeout unlimited unlimited us
解决方法
最后网上搜索之后,有人说 supervisor 有限制,我一检查果然是 supervisor 服务器的最大打开文件数问题:
[supervisord]
...
minfds = 65535
...
改成 655350,之后再看 proc 信息,就好了。
PS: 好像 reload
,reread
,restart
都没用,需要关闭 supervisor 重启服务才能生效。(有待进一步确认)
二、minfds
配置
官方解释:
The minimum number of file descriptors that must be available before supervisord will start successfully. A call to setrlimit will be made to attempt to raise the soft and hard limits of the supervisord process to satisfy minfds. The hard limit may only be raised if supervisord is run as root. supervisord uses file descriptors liberally, and will enter a failure mode when one cannot be obtained from the OS, so it’s useful to be able to specify a minimum value to ensure it doesn’t run out of them during execution. These limits will be inherited by the managed subprocesses. This option is particularly useful on Solaris, which has a low per-process fd limit by default.
Default: 1024
Required: No.
Introduced: 3.0
这个名字很有迷惑性,怎么看也想不到进程的最大打开文件数上面去,不过官方文档也能自洽:这是保证 supervisor 正常启动的一个最小值,相当于一个检查点。然后它会调用 setrlimit 设置子进程的最大打开文件数。