when checked log file /tmp/zabbix_server.log show below:
1365:20160916:132743.845 Starting Zabbix Server. Zabbix 3.0.0beta1 (revision 57867).
1365:20160916:132743.845 ****** Enabled features ******
1365:20160916:132743.845 SNMP monitoring: YES
1365:20160916:132743.845 IPMI monitoring: YES
1365:20160916:132743.845 Web monitoring: YES
1365:20160916:132743.845 VMware monitoring: YES
1365:20160916:132743.845 SMTP authentication: NO
1365:20160916:132743.845 Jabber notifications: NO
1365:20160916:132743.845 Ez Texting notifications: YES
1365:20160916:132743.845 ODBC: YES
1365:20160916:132743.845 SSH2 support: YES
1365:20160916:132743.845 IPv6 support: YES
1365:20160916:132743.845 TLS support: YES
1365:20160916:132743.845 ******************************
1365:20160916:132743.845 using configuration file: /usr/local/etc/zabbix_server.conf
1365:20160916:132743.949 [Z3001] connection to database 'zabbix' failed: [2002] Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
Fixed:
#ln -s /var/lib/mysql/mysql.sock /tmp/mysql.sock
#service mysqld restart
Reference: http://stackoverflow.com/questions/4448467/cant-connect-to-local-mysql-server-through-socket-var-lib-mysql-mysql-sock