前几天晚上，Apache 负载平衡的 Tomcat 实例集群在尝试通过 AJP 进行通信时失败。
我无法弄清楚为什么会发生这种情况，当我没有发现明显的问题时，我也无法让 Apache 进行通信。
编辑
我唯一不确定的是，端口扫描的 8010 端口显示 XMPP 服务。它应该这样显示吗？我想我从来没有注意到过。
我的环境：
- 2 台 CentOs 服务器
- 每个有 2 个 tomcat 实例
- 1个tomcat AJP是8009，另一个是8010
所有的tomcat都会响应各自的HTTP端口。
Nmap结果：
$ ansible integra -a "nmap -p8009-8010 hip-integratc01 hip-integratc02"
hip-integratc02 | SUCCESS | rc=0 >>
Starting Nmap 6.40 ( http://nmap.org ) at 2016-05-13 11:26 EDT
Nmap scan report for hip-integratc01 (10.56.8.226)
Host is up (0.00028s latency).
rDNS record for 10.56.8.226: hip-integratc01.cat.local
PORT STATE SERVICE
8009/tcp open ajp13
8010/tcp open xmpp
Nmap scan report for hip-integratc02 (10.56.8.227)
Host is up (0.00016s latency).
rDNS record for 10.56.8.227: hip-integratc02.cat.local
PORT STATE SERVICE
8009/tcp open ajp13
8010/tcp open xmpp
Nmap done: 2 IP addresses (2 hosts up) scanned in 0.05 seconds
hip-integratc01 | SUCCESS | rc=0 >>
Starting Nmap 6.40 ( http://nmap.org ) at 2016-05-13 11:26 EDT
Nmap scan report for hip-integratc01 (10.56.8.226)
Host is up (0.00016s latency).
rDNS record for 10.56.8.226: hip-integratc01.cat.local
PORT STATE SERVICE
8009/tcp open ajp13
8010/tcp open xmpp
Nmap scan report for hip-integratc02 (10.56.8.227)
Host is up (0.00030s latency).
rDNS record for 10.56.8.227: hip-integratc02.cat.local
PORT STATE SERVICE
8009/tcp open ajp13
8010/tcp open xmpp
Nmap done: 2 IP addresses (2 hosts up) scanned in 6.54 seconds
Netstat 结果：
$ ansible integra -a "netstat -npl" --become
hip-integratc01 | SUCCESS | rc=0 >>
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
...
tcp6 0 0 :::8009 :::* LISTEN 7954/java
tcp6 0 0 :::8010 :::* LISTEN 11190/java
hip-integratc02 | SUCCESS | rc=0 >>
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
...
tcp6 0 0 :::8009 :::* LISTEN 17514/java
tcp6 0 0 :::8010 :::* LISTEN 21084/java
Apache error_log 的要点
[Fri May 13 10:24:44.177672 2016] [proxy:error] [pid 11077] (111)Connection refused: AH00957: AJP: attempt to connect to 10.56.8.227:8010 (hip-integratc02.cat.local) failed
[Fri May 13 10:24:44.177733 2016] [proxy:error] [pid 11077] AH00959: ap_proxy_connect_backend disabling worker for (hip-integratc02.cat.local) for 60s
[Fri May 13 10:24:44.177743 2016] [proxy_ajp:error] [pid 11077] [client 10.56.8.138:6422] AH00896: failed to make connection to backend: hip-integratc02.cat.local
[Fri May 13 10:24:44.177818 2016] [proxy:error] [pid 11077] (111)Connection refused: AH00957: AJP: attempt to connect to 10.56.8.226:8010 (hip-integratc01) failed
[Fri May 13 10:24:44.177830 2016] [proxy:error] [pid 11077] AH00959: ap_proxy_connect_backend disabling worker for (hip-integratc01) for 60s
[Fri May 13 10:24:44.177835 2016] [proxy_ajp:error] [pid 11077] [client 10.56.8.138:6422] AH00896: failed to make connection to backend: hip-integratc01