As a SharePoint Technology Specialist, I have had many phone calls from clients asking me to come in and troubleshoot their SharePoint Server environment. One of the first questions I ask them is if they have configured diagnostic logging.
What is Diagnostic Logging?
Diagnostic logging is the configuration of the amount of log files and the level of the events to log.
Why Setup Diagnostic Logging?
With diagnostic logging turned on you have the ability to troubleshoot any number of issues that may come up including development errors, infrastructure errors, which may be as simple as an authentication problem, routing and email.
You can configure the diagnostic options for event logging for how many events are recorded and the type of event. You can also throttle events for all events or for a single category of events.
Once the log files are being created and events are being logged you can then start the troubleshooting process. This is very time consuming but it does give you the ability to see all events, triggers and calls to and from SharePoint. Upon this review it should give you some insight into what is causing the errors.