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I’ve started using Apache-Exporter¹ for monitoring and checking this weekend how useful it is and how it can be integrated into my Prometheus² monitoring enviroment. The server-status requests inevitably lead to more “background noise” in the Apache logfiles. The screenshot below clearly shows in the upper less section:

Of course the requests cannot be prevented, but you can manipulate what Apache writes in its logfiles. It’s called conditional logging and allows you to set variables with SetEnvIf³ to any regex on each request. With SetEnvIfExpr it is even possible to perform expressions⁴, for instance to check if a request comes from your inside network segments:

SetEnvIfExpr "-R '10.0.0.0/8' || -R '172.16.0.0/12' || -R '192.168.0.0/16'" isInternal

In my case I set the variable “dontlog” on all Server-Status requests and exclude it explicitly in the logging:

SetEnvIf Request_URI "^/server-status(.*)$" dontlog
CustomLog ${APACHE_LOG_DIR}/other_vhosts_access.log vhost_combined env=!dontlog

Further regex statements e.g. for certain file extensions are possible aswell but should be done with caution. Ultimately, too many exceptions tend to make a usually sharp tool for debugging less reliable.

Never trust a log unless it comes from yourself!