Looking at httpd-2.4.3/modules/proxy/mod_proxy.c (about line 1100) I noticed there is no error flagging of workers if the access status is an error and not HTTP_INTERNAL_SERVER_ERROR or HTTP_SERVICE_UNAVAILABLE. Assume DNS resolution failed, so the reverse proxy cannot resolve the server's hostname. If this is only temporarily, simply trying again with the next request might be ok but if it's a permanent situation then it's simply an error.
I attached a small patch to address this. The code can be simplified a bit after the patch (not included in the patch for the sake of brevity). If you have any suggestions to improve the patch, please write me or my colleague mi...@lenk.info. Cheers
worker_error_marking.patch
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