Symptoms

There is a 503 error when opening Workspace
 

Diagnoses

Normally, this issue is caused by incorrect credentials on the application pool identity. We tried to reconfigure by updating the password for the service accounts. Unfortunately, this surfaced another error which prevents us from starting blackpearl through service:

“Windows was unable to open service K2 blackpearl Server for reading on Local Computer.
Error 1060: The specified service does not exist as an installed service.”
 

Resolution

We then resorted to running a repair on blackpearl as well as retyping the credentials wherever applicable. After which, this solved the 503 error. Based on the error messages encountered as we were troubleshooting, it points back to the service accounts used. Running a repair on blackpearl and updating the credentials of the service accounts was able to resolve the issue.

Here's some information regarding this error which could be useful:
http://support.microsoft.com/kb/943891
http://www.microsoft.com/technet/prodtechnol/windowsserver2003/library/iis/55f71614-ef1b-4015-b9c8-a42c1e700c25.mspx?mfr=true
http://stackoverflow.com/questions/4150952/what-possibilities-can-cause-service-unavailable-503-error