# mongo
MongoDB shell version: 3.0.2
connecting to: test
Server has startup warnings:
2015-05-09T12:34:19.688-0700 I CONTROL [initandlisten]
2015-05-09T12:34:19.688-0700 I CONTROL [initandlisten] ** WARNING: soft rlimits too low. rlimits set to 1024 processes, 64000 files. Number of processes should be at least 32000 : 0.5 times number of files.
>
mongodb当前限制：1024 processes, 64000 files
mongodb建议要求：processes = 0.5*files=32000（至少）
所以需要将 processes 从1024 改为 32000 或更大.
查看当前mongodb进程信息：
[[email protected] ~]# ps -ef | grep mongod
mongod 24283 1 0 12:35 ? 00:00:04 /usr/bin/mongod -f /etc/mongod.conf root 24240 22049 0 12:45 pts/2 00:00:00 grep mongod
[[email protected] ~]# cat /proc/24283/limits
#可以看到限制：Max processes，Max open files
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 1024 32000 processes Max open files 64000 64000 files Max locked memory 65536 65536 bytes Max address space unlimited unlimited bytes Max file locks unlimited unlimited locks Max pending signals 14833 14833 signals Max msgqueue size 819200 819200 bytes Max nice priority 0 0 Max realtime priority 0 0 Max realtime timeout unlimited unlimited us
修改 Max processes 或者 files ，有几种方法：
方法一：
修改配置文件 /etc/security/limits.d/90-nproc.conf
[[email protected] ~]# vi /etc/security/limits.d/90-nproc.conf
* soft nproc 1024 改为: * soft nproc 32000
重启 mongod 服务：
[[email protected] ~]# service mongod restart
方法二：
修改配置文件 /etc/security/limits.conf，添加配置信息：
[[email protected] ~]# vi /etc/security/limits.conf
mongod soft nofile 64000 mongod hard nofile 64000 mongod soft nproc 32000 mongod hard nproc 32000
重启 mongod 服务：
[[email protected] ~]# service mongod restart
也可以查看 limits.conf 更多配置信息和使用方法：
[[email protected] ~]# man limits.conf
查看系统限制：
[[email protected] ~]# ulimit -a
core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 14833 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1024 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) 14833 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited
mongodb推荐设置：
-f (file size): unlimited -t (cpu time): unlimited -v (virtual memory): unlimited -n (open files): 64000 -m (memory size): unlimited -u (processes/threads): 64000
直接在当前shell中设置：ulimit -n <value>
ulimit -f unlimited ulimit -t unlimited ulimit -v unlimited ulimit -n 64000 ulimit -m unlimited ulimit -u 64000
若要系统启动时在所有生效，将上面的 ulimit 添加到 /etc/profile
[[email protected] ~]# vi /etc/profile