MongDB mongod.log WARNING: soft rlimits too low

# 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：

[root@localhost ~]# ps -ef | grep mongod

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1. mongod   24283     1  0 12:35 ?        00:00:04 /usr/bin/mongod -f /etc/mongod.conf  
2. root     24240 22049  0 12:45 pts/2    00:00:00 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

[root@localhost ~]# cat /proc/24283/limits

#可以看到限制：Max processes，Max open files 

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1. Limit                     Soft Limit           Hard Limit           Units       
2. Max cpu time              unlimited            unlimited            seconds     
3. Max file size             unlimited            unlimited            bytes       
4. Max data size             unlimited            unlimited            bytes       
5. Max stack size            10485760             unlimited            bytes       
6. Max core file size        0                    unlimited            bytes       
7. Max resident set          unlimited            unlimited            bytes       
8. Max processes             1024                 32000                processes   
9. Max open files            64000                64000                files       
10. Max locked memory         65536                65536                bytes       
11. Max address space         unlimited            unlimited            bytes       
12. Max file locks            unlimited            unlimited            locks       
13. Max pending signals       14833                14833                signals     
14. Max msgqueue size         819200               819200               bytes       
15. Max nice priority         0                    0                      
16. Max realtime priority     0                    0                      
17. Max realtime timeout      unlimited            unlimited            us      

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  

[root@localhost ~]# vi /etc/security/limits.d/90-nproc.conf 

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1. *          soft    nproc     1024  
2. 改为:  
3. *          soft    nproc     32000  

*          soft    nproc     1024
改为:
*          soft    nproc     32000

重启 mongod 服务：

[root@localhost ~]# service mongod restart