[5.x] Throw exception when minProcesses is set to zero

[themsaid]

No description provided.

[dillingham]

@themsaid thanks for adding this. Just a thought.. what if this and others described in your book were part of a horizon:validate command so they could be discovered sooner? Might also be a nice reference of all the ways we can misconfigure things and added to CI pipelines before deploying

[ThaDaVos]

Out of curiosity - why was this changed? I've had no issues having it set to 0 - keeps the CPU nice and quiet for me - especially when running locally during development

[driesvints]

There always needs to be at least one process. Otherwise it doesn't work.

[ThaDaVos]

I've got a whole project setup with multiple queues (it's lumen, so probably used Horizon 3 or 4 I guess) - but all queues are set to minProcesses 0 - it may take a second, but they still do pickup their jobs and process them