谈谈Memcached与Redis

1、检查用户打开的进程数
ps -U work | wc -l
2、检查用户打开的文件数
lsof ｜grep work | wc -l
3、检查 limits.conf 都很大，没什么问题。
* soft nofile 65535
* hard nofile 65535
4、检查nproc 默认为1024

这个nproc的值偏小，需要调大
grep 'nproc' --color /etc/security/limits.d/90-nproc.conf



解决方案：
方法一：
vim /etc/security/limits.conf

work soft nproc 10240
work hard nproc 10240
work soft nofile 65536
work hard nofile 65536
* soft nofile 65535
* hard nofile 65535

重新su work，就可以啦

方法二：
将nproc的值改大
vim /etc/security/limits.d/90-nproc.conf
* soft nproc 10240

重重新su work，也是可以的

++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/etc/security/limits.conf配置，本人只截取了一部分常用的，具体内容查看参考文档
can be one of the following:

core- limits the core file size (KB) #限制core大小，默认为0。ulimit -c xxx可以修改（临时生效）

data- max data size (KB)

fsize- maximum filesize (KB)

memlock- max locked-in-memory address space (KB)

nofile- max number of open files #打开最大数目, ulimit -n xxx(临时生效)

rss- max resident set size (KB)

stack- max stack size (KB)

cpu- max CPU time (MIN)

nproc- max number of processes #进程的最大数目（默认1024），ulimit -u xxx(临时生效)

as- address space limit

maxlogins- max number of logins for this user

maxsyslogins- max number of logins on system

priority- the priority to run user process with (negative values boost process priority)

locks- max locked files

If a type of "-'' is specified without supplying the item and value fields then no limits are enforced.
The first entry of the form which applies to the authenticating user will override all other entries in the limits configuration file.
In general, individual limits have priority over group limits, so if no limits is imposed for a given group, but one of the members in this group have a limits line, the user will have its limits set according to this line.
Please note that all limit settings are set per login. They are not global, nor are they permanent; existing only for the duration of the session.

具体ulimit参数，查看参考文档

参考文档：
1、http://www.novell.com/support/kb/doc.php?id=3007194
2、http://blog.csdn.net/lixiaohuiok111/article/details/8854028
3、http://www.361way.com/resource-ulimit/2611.html
4、http://blog.sina.com.cn/s/blog_573a052b0100pkhc.html

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