zabbix-server does not start - zbx_tcp_listen() fatal error

Zabbix 2.4.x
CentOS 6.6

Although I have rarely seen something like this but my deployment of Zabbix via Puppet caused a very strange issue where Zabbix service would not start

Error in logs
listener failed: zbx_tcp_listen() fatal error: unable to serve on any address [[-]:10051]

Service status and when trying to start
[root@abc-zabserver-b zabbix]# service zabbix-server status
zabbix_server is stopped
[root@abc-zabserver-b zabbix]# service zabbix-server start
Starting Zabbix server:                                    [  OK  ]
[root@abc-zabserver-b zabbix]# service zabbix-server status
zabbix_server is stopped

Process is running (sometimes shows multiple processes running)
[root@abc-zabserver-b zabbix]# ps afx | grep -i zabbix
 3852 pts/1    S+     0:00  |       \_ grep -i zabbix
 2150 ?        S      0:00 zabbix_server -c /etc/zabbix/zabbix_server.conf

But service is still stopped
[root@abc-zabserver-b zabbix]# service zabbix-server status
zabbix_server is stopped

If I kill the process(es) then Zabbix service comes up fine.
Cause
When I was deploying Zabbix with Puppet I was using
ensure => installed
instead of
ensure => '2.4.1.-5.el6' (or some other specific version)

Basically my config file for Zabbix was still and older version and it didn't play too well with the new Zabbix that became available through the repos.

I ended up refreshing the config file.

Decrease timeout for Zabbix OK blinker

version: Zabbix Server 2.4

The default time for OK and status change trigger is 30 minutes which means the OK keeps blinking on the screen for that long. 

There are two ways to change this:

Go to Administration > General > Trigger displaying options (drop down on right)
Change values of following as desired

• Display OK triggers for
• On status change triggers blink for

The other way is to directly change it in DB (MySQL in this case):

mysql -u zabbix -p <PASSWORD> -e 'UPDATE config SET `ok_period`=60, `blink_period`=60' zabbixserverdb

This is more helpful for automation.