Error communicating with backend module...

[Bernd Welter]

Sometimes users encounter the following error message - which is quite generic:

Internal error occurred during request: Error communicating with backend module ...

The documentation mentions :

When the module crashes the statistics log ${sys:xserver.logdirectory}/request-statistics.log shows the service operation called, indicates non-success with false, and states Error communicating with backend module. The exit code is arbitrary, very often the logs directory contains a file hs_err_pid<pid>.log.

Here's also some feedback from DEV (Haba):

This error message shows a severe crash of an xServer and we are very interested in knowing the cause for the crash. Therefore please ALWAYS create a helpdesk ticket and provide request and response which will enable us to reproduce the case (hopefully). It is also important that the xServer instance recognizes the condition automatically and restarts the backend module. This might have a negative impact on performance and such requests could also be used for DoS attacks. There could be hundreds of potential reasons - usually being located in the C++ part of the server (due to insufficient memory or malicious allocation).

So based on this I recommend to capture

• the request-statistics.log referencing the malicious request
• the process file (hs_err...)
• the underlying request / response
• determinism / reproduction state: does the same request always cause the module to crash?

If the content of these files does not help you to fix the issue on your own please create a support ticket and provide these files to support.

Bernd