Server Flood Protection Considerations

The Stress Test Tool will send lots of requests in a very short period. All these requests are sent from the same IP to the uniGUI application under test. Your server OS may interpret this high volume of requests as a flood DOS (Denial Of Service) attack and start blocking such requests. It is even more suspicious when you run the Stress Test Tool from a remote PC with PlayBack speed set at Max Speed for a long period. Since flood detection algorithms vary from OS to OS and highly depend on their particular configuration and server software, it is hard to predict when such blockages may occur. When the server starts blocking requests you will notice lots of HTTP error messages in the right side memo in Stress Test Tool. That will indicate that requests are being blocked and are not reaching their target.

For example, behavior will be different when running the uniGUI app as ISAPI module in IIS, standalone EXE, and Windows Service. While running the Stress Test Tool from a remote PC may trigger flood protection, running both uniGUI app and Stress Test Tool on the same desktop should work without triggering any flood protection mechanisms.

In addition to the server OS, some 3rd-party protection software such as Kaspersky, Symantec, etc. may add other layers of protection to your server IP traffic which may disallow fast and continuous requests coming from Stress Test Tool. In such cases, you need to slow down the playback speed by setting it to Real Time and/or putting a longer delay between Runs to allow the requests pass through the anti-flood detection layers.

If you see many HTTP errors in the Stress Test Tool memo during a run, that likely means requests are being blocked by the server or intermediary protection layers. Reduce playback speed and/or increase delays between runs.