It may provide some insight if it happens again. If it is replicable within the core Wowza product without any custom code enabled then I'd suggest raising this as a
support ticket, quoting this forum thread. The heap dump file would also be very useful.
If you check your access logs (found in your [install-dir]/logs, and you find SKIP messages, this normally means that your hardware/OS is struggling to keep up with your transcoding process. This would depend on the quality of the video that you are ingesting and decoding, and the quality of the output bit rate renditions that you are encoding. If you find these, you might want to tune your server using our