Apache 2.4.54 - Enabling Keep-Alive Causes Intermittent Connection Refused Errors
I'm migrating some code and I'm dealing with I'm working with an scenario with my Apache 2.4.54 server where enabling Keep-Alive results in intermittent 'Connection Refused' errors from clients. This scenario becomes apparent when multiple clients attempt to open persistent connections simultaneously. I've configured Keep-Alive in my Apache configuration file as follows: ```apache KeepAlive On MaxKeepAliveRequests 100 KeepAliveTimeout 5 ``` Despite this configuration, I see errors in the logs like: ``` [behavior] [client xx.xx.xx.xx] Connection refused ``` This typically happens under load, and the server becomes unresponsive for a short period. To troubleshoot, I've tried increasing `MaxKeepAliveRequests` to 200 and adjusting the `KeepAliveTimeout` to 10 seconds, but it hasn’t made a important difference. I also checked the `ServerLimit` and `MaxRequestWorkers` settings, which are set to: ```apache ServerLimit 256 MaxRequestWorkers 200 ``` However, I still run into these connection issues. I’m running an event MPM with the following settings: ```apache <IfModule mpm_event_module> StartServers 5 MinSpareThreads 25 MaxSpareThreads 75 ThreadLimit 64 ThreadsPerChild 25 MaxRequestWorkers 200 MaxConnectionsPerChild 0 </IfModule> ``` I also verified that my firewall settings allow for the necessary ports. I suspect there might be a conflict with my backend service or resource limits affecting Keep-Alive functionality. Has anyone experienced similar issues or have suggestions on how to resolve this? My team is using Apache for this CLI tool. Any examples would be super helpful. I've been using Apache for about a year now. Any examples would be super helpful.