Hi all

I have a .net forms application that uses a webservice and calls several methods on the service, and everything works as it should. Well, almost that is... And I hope some of you can help me troubleshoot the problem, and I'm posting here because I think it's the webservice that is the problem.

My problem is that I'm getting a fixed response time of ~500 millis on every call I make to the service. And since these calls are done to localhost they should in theory send response data instantly to my application. Please note that is doesn't matter if the webservice method is a simple HelloWorld method or a method that actually returns something usefull. The webservice has been added to application solution through Web references in VS.

If I for example call several methods after each other I get the following timing result:

21:25:42 689 - Call HelloWorld1()
21:25:43 296 - Call HelloWorld2()
21:25:43 793 - Call HelloWorld3()
21:25:44 293 - Call HelloWorld4()
21:25:44 793 - Call HelloWorld5()
21:25:45 293 - Call HelloWorld6()

The calls have to be sync. calls, but I did try async calls just to varify the response time, but with no difference.

While trying to troubleshoot why I get this strange 500 millis delay on every call, I've tried making a sort of ping/download tool with HttpWebRequest, and here I get something I don't understand.

When I use HttpWebRequest and download the webservice.asmx url I get the same 500 millis delay, but if I add ?op=HelloWorld in the url something finally happens. The response time is down to 4-5 millis, which is what it should be.

Ok, So I thought, then I just use HttpWebRequest and call the webservice with post data and use webservice.asmx/HelloWorld in the url. But no, same result: 500 millis delay on every response :(

This is really beginning to bug me a lot and I hope someone can help me :)

I'm a bit surprised that noone has an opinion on this or have experienced something similar.

Since my first post I've been testing and debugging a bit, and at first I thought it was my coding that needed some attention. But now I've confirmed that everything is working as it should. While debugging and testing I've tried different Windows versions and to my big surprise Windows XP is the winner as I'll show here:

For the record, I have a laptop which runs Windows XP and a desktop machine running Vista and they're set up on a local network with internet. I'm developing the application on my desktop where I also have a localhost for testing the webservice.

While testing and debugging I tried executing the application on my laptop(Windows XP) and made it call the webservice hosted on my desktop over the local network, and also tried making it call my real webhost. In both cases it's super fast! Calling over the local network I get responses ranging from ~10 to ~80 millis pr. method call. The 80 millis response is a method returing around 2000 records, so it's expected to take that time to download. The average for all 11 calls is about 30-40 millis. The response times are of course a bit higher when calling the webhost, but not more than expected. 50-350 millis and less than 100 on average.

Executing the exact same application on either vista og 7 I get super slow response times(min. 500 millis) and it doesn't matter whether the webservice is on my localhost or my webhost. And since I can call the webservice on my localhost from my laptop over the local network with super speeds I get really confused.

So right now my conclusion is that my application is working as it should, and that vista and 7 have a problem...

Anyone know what's going on here?

Woot... Problem solved!

Today I found this thread which basically describes the same problem that I was having.

Apparently the problem is NOD32 Antivirus 4, but only when installed on Windows Vista/7. Windows XP has no problem with NOD32 installed. I use NOD32 on both my machines.

To solve the problem I went to NOD32 > Advanced setup > Web access protection > HTTP, HTTPS and unchecked Enable Http Checking.

Now my web service calls are super fast again.

nice info...kudos !!