My sendmail server started rejecting connections because load average was too high (due to a spam issue that has since been resolved).
Error was: sendmail: rejecting connections on daemon MTA: load average: 50
I'd like to understand this behavior better though.
- Where is this threshold set?
- What does "load average" mean?
- How often is load average calculated?
- Is there a way to proactively monitor this? Or becoming alerted when load average approaches a high value? Obviously sendmail will give a 4.0.0 class dsn to the connecting MTA but I was homing for some sort of alert mechanism.
I thought I'd bump this one more time as I saw it come up again. The issue I'm now seeing is that messages that are queued due to exceeding load average don't get resent later (even after performance returns to acceptable levels. Any idea why this could be?