I think this is a bug in Snowplow Avalanche or Gattling, I’ve been getting a few of these this morning while load testing. I believe the client should be handling this exception and re-opening a new SSL session. Do you agree? Should I report this as a github issue?
I think I tracked it down to my collector nodes running out of file descriptors. I increased the ulimit nofile setting for that user in /etc/security/limits.conf and have not seen this error since making that change.