Problem: Sporadic "Rejected HTTP validation request" on Windows.

Resolution:

After digging through our code and inspecting carefully, this seemed to be a problem due the Operating System settings on Windows.

Windows by default had send and receive buffers for the sockets set to a size of 8k. This seems to be overloaded when we run our automation tests and sometimes, one of the requests get dropped due to the buffers being full.

These values, when looked up in Linux and Solaris systems seems to be much larger by default. In order to handle such load better, the send and receive buffers in Windows should be increased from their defaults. These settings are to be added in the registry ( by default they are absent ).

The figure in the attachment shows the settings in the registry.

In the Windows Registry, under HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/AFD/Parameters/

• Add couple of REG_DWORDs , namely:

• DefaultReceiveWindow ( decimal value 32768) corresponding to a 32k buffer
• DefaultSendWindow ( decimal value 16384 ) corresponding to a 16k buffer.
• For higher loads, one could potentially increase the ReceiveWindow size, keeping in mind the memory allocation for the same.