question on logging statement about consul-alerts HOT 2 CLOSED

Basically how the health checks work is it waits for a change in the health checks and then triggers the health-check-notify logic which runs for ~60 seconds. This process is not concurrent and any change in the health check while the process is running will wait for it to finish before running the process again. Basically queueing up.

I tried to avoid a very long queue to run the health-check-notify process which would cause it to run for a long time in case the consul health changes very often (possibly flapping). So the fix was to allow only 1 process request to wait instead of having a queue.

Given that flapping sometimes occur in a system, I tried to avoid something like this:

(for a given 60 seconds)
consul triggered health check --> process runs for 60 seconds
consul triggered health check --> process waits then run another 60 seconds
consul triggered health check --> process waits then run another 60 seconds
consul triggered health check --> process waits then run another 60 seconds

This would end up with the process running for ~ 4 mins to check the health changes.

The solution I added was to have only one process waiting instead of a queue:

(for a given 60 seconds)
consul triggered health check --> process runs for 60 seconds
consul triggered health check --> process waits then run another 60 seconds
consul triggered health check --> replaces currently waiting process
consul triggered health check --> replaces currently waiting process

This then would prevent the consul health check flapping from queueing up and making the process run longer than necessary.

Basically it's just a log saying that "there's another health check change and there's already a health-check-notify process running and there's also another one waiting when it's done, so I'm not adding to the queue". (It needs a better description though or I should just remove it from the log).

Hope that explains it. :) I should probably remove that log. :)

from consul-alerts.

That certainly does explain it, thanks for taking the time to provide such a complete explanation!

from consul-alerts.