How to configure postfix under Ubuntu 16.04 to securely use Google's smtp relay service.
I was experiencing connection timeouts on my RabbitMQ daemons when the system had accumulated 90-minutes of inactivity. Even though I had enabled the native (to RabbitMQ) keep-alive feature, node.js connection requests were still crashing the system.
This article identifies why the heart-beat feature does not work in PHP and provides a work-around solution to the issue.
"What I was seeing was that, when I started the demon, I would get a success message (mongod start/running, process xxxxxx) but there would be no mongod process running. Additionally, even though I have my (development) logging set to the highest levels, not one error message appeared in the log to provide a hint as to why the service failed to start."