MHA实现MySQL高可用的时候，MHA复制功能检测老是出现各种问题，故总结一下常见报错以及如何解决的
1.某个库 Dead Servers
检测从库状态发现一切正常，那是哪里出问题了呢？

Sun Jul 28 09:27:40 2019 - [info] Dead Servers:
Sun Jul 28 09:27:40 2019 - [info]   172.25.13.13(172.25.13.13:3306)

查看server3（IP地址为172.25.13.13）的防火墙！！！

做测试的时候尽量把防火墙都关掉，防火墙会影响3306端口！！！
2. master_ip_failover_script报错

Sun Jul 28 09:30:48 2019 - [info] Checking replication health on 172.25.13.11..
Sun Jul 28 09:30:48 2019 - [info]  ok.
Sun Jul 28 09:30:48 2019 - [info] Checking replication health on 172.25.13.13..
Sun Jul 28 09:30:48 2019 - [info]  ok.
Sun Jul 28 09:30:48 2019 - [info] Checking master_ip_failover_script status:
Sun Jul 28 09:30:48 2019 - [info]   /usr/local/bin/master_ip_failover --command=status --ssh_user=root --orig_master_host=172.25.13.12 --orig_master_ip=172.25.13.12 --orig_master_port=3306 
Bareword "FIXME_xxx" not allowed while "strict subs" in use at /usr/local/bin/master_ip_failover line 79.
Execution of /usr/local/bin/master_ip_failover aborted due to compilation errors.
Sun Jul 28 09:30:48 2019 - [error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln229]  Failed to get master_ip_failover_script status with return code 255:0.
Sun Jul 28 09:30:48 2019 - [error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln427] Error happened on checking configurations.  at /usr/bin/masterha_check_repl line 48.
Sun Jul 28 09:30:48 2019 - [error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln525] Error happened on monitoring servers.
Sun Jul 28 09:30:48 2019 - [info] Got exit code 1 (Not master dead).

MySQL Replication Health is NOT OK!

我的解决方案是把它在 /etc/masterha/app1.cnf屏蔽掉

发现MHA复制功能检测成功