Question: When we install Spectrum connector, it asks for OneClick User credentials...why connector installation require this username and password?
Solution: Oneclick user credentials are required when installing Spectrum Connector to fetch the Spectrum environment, Spectroserver status etc. This is one time activity, if the OC user password changes at later stage, the connector works without any problem.
I'm not so sure its a one time event I believe it is cached as well. I have two Spectrum OneClick servers that are load balanced and when I forget to push the EventFormat and PCause files to the other server as well as and also forget to "Update Event and Alarm files" on the Spectrum Admin page of the server that should have the files. I get that message only when the SOI URL is sent to the server with the missing files.
Here is would do this to prove that theory...
Create a new event make it like a critical alarm with some description and what not and then test it. If you look at the alarm in SOI it will probably say something like "Unknown alarm details missing probable cause" in the alarm description.
At least in prior versions, Spectrum connector talks to Oneclick everytime it processes a new alert. When no cached, Information about PCAUSE and alarm title are recovered from Spectrum Oneclick. So, OC username and password matter.