IIS7/.NET web services - Error when one web service calls another

I need a little help solving an issue regarding .NET web services. I have a desktop application that consumes my main web service. One of the methods gets some report data, but in order to do that, web service (A) calls a method in web service (B). Depending what parameters I pass into "A"s method, it either works or fails. If I pass in a filter, the dataset is pretty small, when I don't pass in a filter obviously the dataset is very large. Additionally, if I run web service "A" in debug mode and point my desktop app to the local version (meanwhile B is on our production server), it works wether I filter the data or not. The error I get is a 502 Bad Gateway on production, and a 502 - Web server received an invalid response while acting as a gateway or proxy server.

We have a web farm with some ARR's, so I went into the web farm's ARR, and found "Proxy" settings and adjusted the timeout to 1200 seconds (whereas my app usually fails within 20-30 seconds) and I'm still receive this error. The HTTP version is in "Pass through" mode with the "keep alive" checkbox checked.

We have no issues using a windows service consuming a web service or anything like that, 开发者_JS百科just when one web service consumes another web service.

Addition, I'm not using any sessions in my web service methods, and I believe the webmethod I call in web service "B" does have a cacheduration value set of 5 minutes.

I'm scratching my head on this for my lack of knowledge of IIS 7, and many other things. If anyone has any ideas or can point me in the right direction I would certainly appreciate it.

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I thought I'd come here and answer this question in case anyone else ran into the same issue. This issue was not server related at all. It was code related. In my code I had a datatable (c#), and was doing a datatable.select(....) where I would pass in a filter with many "OR"'s. Ex. Filter = 'x' OR 'y' OR 'z' etc etc. I had around 100 of these, which caused the datatable.select method to produce a stackoverflow exception. I changed the code to do an "IN (x,y,z)" and it works fine now. Hope this helps someone.