Receiving empty response from servlet

I have an ajax web application requesting data to servlet deployed on Tomcat 5.5. I am connecting to Tomcat using HTTPS protocol.

I wrote one servlet which is called from ajax page and it responds in the form of XML as <response></response>. But sometimes, I receive response as empty, nothing in it, just blank (and I confess that I am not sending any blank response in any way).

I investigated Tomcat access logs and it shows me following entry:

<Ti开发者_如何学Pythonme> \MyServlet HTTP/1.1" 200 -

Which means that my request was OK, fulfilled and response bytes are zero as -.

I did not find any error/exception in Tomcat logs as well.

I have no idea from where this empty response comes as my server side logs does not contain any detail for this request.

When I tried to debug the servlet by adding some logging statements, those statements are not even getting printed. I am assuming that service method is not even executed.

Is this due to Tomcat?

is there specific number of threads/request that Tomcat 5.5 can handle?