1.nagio伺服器發出報警日誌，客戶端ssl handshake失敗：

***** Nagios *****   Notification Type: PROBLEM   Service: Check Zombie Procs Host: xxx Address: xxx State: CRITICAL   Date/Time: Tue Nov 7 02:25:03 CST 2017   Additional Info:   CHECK_NRPE: Error - Could not complete SSL handshake.

2.檢視客戶端日誌（cat /proc/sys/fs/file-max）：

56700 Nov  6 23:51:02 xxx nrpe[21537]: Config file '/usr/local/nagios/etc/nrpe.cfg' contained errors, aborting...
56701 Nov  6 23:51:02 xxx xinetd[21538]: warning: cannot open /etc/hosts.allow: Too many open files in system
56702 Nov  6 23:51:02 xxx xinetd[21538]: warning: cannot open /etc/hosts.deny: Too many open files in system

系統開啟檔案過多！

3.檢視Linux下檔案限制

[[email protected] abrt]# cat /proc/sys/fs/file-max
10240
[[email protected] abrt]# ulimit -n
65535

其中，

ulimit其實就是對單一程式的限制,程序級別的

file-max是所有程序最大的檔案數

nr_open是單個程序可分配的最大檔案數

所以，file-max過小

4.設定file-max

echo 655350 >  /proc/sys/fs/file-max