Couple points here:
1) audio4 is a relay server, not a receiver server, so your feed actually remains online (just no one could listen to it when it went down). The minute your feed stops broadcasting to us, the premium subscription drops. In all of these cases your feeds continued to broadcast to us (and be archived), so there was no impact.
2) We've implemented extensive monitoring and restarting procedures to prevent this from happening again. If, again for some reason the server dies, it will not remain down for more than 30 seconds and it will be automatically brought back up and I'll be paged.
We're not sure why this issue is limited to audio4 - it's not the server crashing but the process which relays the feeds which is crashing. We use the same standard software and configuration across all 4 of our audio servers, so this issue is perplexing. But, from this point forward there should be minimal to no impact to listeners since we're proactively addressing the issue now.
Thanks,