Recently, I have migrated our Nagios from One Server to Other. Everything(Installation, configuration and migration) has been completed successfully. Now something starts happening strange "Whenever I tried to access Nagsio from Web Interface, It was so slow and even I have to click 3-4 time on link to get output". It was seriously so irritating. Initially I thought that there may be some issues with Performance of Web Server and its not able to handle CGI request properly and thus taking time.
But I was worried that for day to day monitoring activities it will be a headache to click one link again and again to get response. There seems something wrong with server. Then I have searched the logs and found below continuous WARNING messages in nagios.log file.
Warning: Check result queue contained results for service ' ' on host ' ', but the service could not be found! Perhaps you forgot to define the service in your config files?"
After doing some search I found this may be due to two nagios processes running at same time, which were checking all configured processes on different intervals and creating issues. Then I have stopped Nagios using init script. After this when I ran ps -ef to find other nagios process, then it shows me another one :).
Then I though ohhh this was creating issue. Now I have restarted the nagios again and everything seems working fine :).