前言
问题 : 手机上收到tomcat server【80】 down信息，服务down掉，往往都是有重启操作。重启失败才会报警。如果重启操作执行了，我们就需要查看为何不能启动？
Trigger: Tomcat service【80】is down
Trigger status: PROBLEM
Trigger severity: Disaster
Trigger URL:
Item values:
1. Tomcat status (192.168.96.200:net.tcp.listen[80]): 0
2. *UNKNOWN* (*UNKNOWN*:*UNKNOWN*): *UNKNOWN*
3. *UNKNOWN* (*UNKNOWN*:*UNKNOWN*): *UNKNOWN*
Original event
__主机说明__：
192.168.96.113: zabbix server 192.168.96.115: zabbix proxy 用于监控主机 192.168.96.200: 被监控的主机
1. 先查看重启动作是否执行。
服务down掉，往往都是有重启操作。重启失败才会报警。如果重启操作执行了，我们就需要查看为何不能启动？首先确保重启操作是否实行成功。登录zabbix web端查看动作的执行，【报表】--> 【动作日志】如下图：
如图，可以看到此命令执行失败，并且提示可能是访问拒绝。我们需要进一步确认出错是否为访问问题。
2. 查看执行命令主机日志
登录192.168.96.200，并查看其zabbix agent端日志。
[root@GPU ~]# tail -5 /var/log/zabbix/zabbix_agentd.log
2325:20170906:192653.587 active check configuration update from [192.168.96.115:10051] started to fail (cannot connect to [[192.168.96.115]:10051]: [4] Interrupted system call)
2325:20170906:192753.599 active check configuration update from [192.168.96.115:10051] is working again
2322:20170906:192754.512 failed to accept an incoming connection: connection from "192.168.96.113" rejected, allowed hosts: "192.168.96.115"
2324:20170906:155824.924 failed to accept an incoming connection: connection from "192.168.96.113" rejected, allowed hosts: "192.168.96.115"
2323:20170906:160824.587 failed to accept an incoming connection: connection from "192.168.96.113" rejected, allowed hosts: "192.168.96.115"
从日志中我们可以知道，zabbix server 192.168.96.113 试图与 192.168.96.200建立连接，192.168.96.200拒绝连接，因为他只能允许192.168.96.115。
3. 解决问题
192.168.96.113用代理服务器192.168.96.115采集数据，而远程命令是无法交由proxy执行(zabbix server 和zabbix proxy 支持的文件看附录一)。
grep ^[A-Z] /etc/zabbix/zabbix_agentd.conf
PidFile=/var/run/zabbix/zabbix_agentd.pid
LogFile=/var/log/zabbix/zabbix_agentd.log
LogFileSize=0
EnableRemoteCommands=1
LogRemoteCommands=1
Server=192.168.96.115
ServerActive=192.168.96.115
Hostname=192.168.96.200
Include=/etc/zabbix/zabbix_agentd.d/
可以看到server仅为192.168.96.115,故192.168.96.113无法执行远程命令。我们需要将___server=10.60.96.115修改为server=10.60.96.113,10.60.96.115___。
注意 : zabbix agent 配置文件修改需要重启服务，
centos 6上： ~]# service zabbix-agent start
centos 7 上：~]# systemctl start zabbix-agent
编译安装：请找到安装目录下的sbin目录，并运行zabbix_agentd命令。
附录一：
| Function | Supported by proxy |
|---|---|
| Zabbix agent checks | Yes |
| Zabbix agent checks (active) | Yes |
| Simple checks | Yes |
| Trapper items | Yes |
| SNMP checks | Yes |
| SNMP traps | Yes |
| IPMI checks | Yes |
| JMX checks | Yes |
| Log file monitoring | Yes |
| Internal checks | Yes |
| SSH checks | Yes |
| Telnet checks | Yes |
| External checks | Yes |
| Built-in web monitoring | Yes |
| Network discovery | Yes |
| Low-level discovery | Yes |
| Calculating triggers | No |
| Processing events | No |
| Sending alerts | No |
| Remote commands * | No |
