Question

long time ago I wrote webservice that is still in use. Now I plan to refactor it. The webservice is full of most likely unused functions and I have no idea how it is used by the clients. In order to strip away the unused functions I need to analyze the function calls and data of currently installed webservice.

Is there a (free/opensource) tool that will enable me to log all activities of the webservice.

The ideal output of the tool I’m looking for could be a database containing all the called functions and a list of the data that was send to it for each call.

Solution

With the help of Martins answer I created this HttpModule which does exactly what I wanted:

public class LoggingModule : IHttpModule {     void IHttpModule.Init(HttpApplication context)     {         context.BeginRequest += new EventHandler(BeginRequest);     }      private void BeginRequest(object sender, EventArgs e)     {            TryAppendLog("Content-Type");         TryAppendLog("SOAPAction");     }      void TryAppendLog(string key)     {         string value = HttpContext.Current.Request.Headers[key];         if (string.IsNullOrEmpty(value)) { return; }                     HttpContext.Current.Response             .AppendToLog(string.Format("{0}: {1} ", key, value));                }      #region IHttpModule Member     public void Dispose() { }     #endregion } 

Answer 1

As Kobi wrote, you can find the required information in the IIS log files (i.e. in c:\WINDOWS\system32\LogFiles\W3SVC1).

If you want to log the usage into a database, you could write a simple HttpModule, which checks every request, and logs it into the DB if it is a call to your web service. E.g. here’s the relevant parts of a very simple HttpModule, which logs calls to mywebservice.asmx:

public class MyWebServiceDiagnosticsModule : IHttpModule {     public MyWebServiceDiagnosticsModule ()     {     }     void IHttpModule.Init(HttpApplication context)     {         context.BeginRequest += new EventHandler(BeginRequest);     }     private void BeginRequest(object sender, EventArgs e)     {         HttpContext ctx = HttpContext.Current;         string url = ctx.Request.Url.ToString().ToLower();         if (url.Contains('mywebservice.asmx'))         {             LogMethodCall(url); // parse URL and write to DB         }     } }