We are currently monitoring application URLs using the "Website Monitoring" add-on. However, many URLs are returning null values for the response code, indicated as (response_code="" total_time="" request_time="" timed_out=True). This results in "timed_out=True" errors, making it impossible to monitor critical URLs and applications in the production environment.
An urgent assistance is require to resolve this issue. Prompt support would be highly appreciated and invaluable.
As for the timeout issue - it is most probably a network-related issue. A client tried to establish a connection and request some resource but didn't manage to do it in an allocated time window so returned a timeout error. This needs verifying on your end - whether the sites which are to be monitored are reachable, what connection parameters you use (or what are the default parameters if the addon doesn't let you specify them) and so on.
As for "urgent assistance is required" - this is a volunteer-based community. People use their spare time to help others. For "urgent assistance" you typically go and pay. Splunk Answers is not a substitution for support or professional services.
Timeouts are a client-side concept - the "client" has given up waiting for a response. This may be due to a number of reasons. Often with web applications, the webserver is waiting for resources e.g. a thread, in order to execute the request and when one is not available "in time", a "timeout" is reported. Check whether your timeouts are clustered around particular URLs, or particular times of day, and investigate what is going on on your webservers for those URLs or times of day.