RisingWave Community - What does 'channel closed' mean in a query error?

'Channel closed' in a query error typically indicates a communication issue or failure between different components of the system.
It could be related to a node crash or a stream actor exiting unexpectedly.
To resolve this error, checking logs of compute nodes, dropping and rebuilding the stream job, restarting the system, and going through the recovery process can be helpful.
In Mark's case, restarting everything resolved the issue, but the root cause of how it got into that state remains unknown.