Github user Tagar commented on the issue:
https://github.com/apache/zeppelin/pull/2802
@zjffdu I don't have a reproducible case yet. This error hasn't been very
consistent for me so it might be also a side effect of another problem. That's
why I asked above if we could capture exceptions in grpc better. Also check
what you think of the suggestion made in grpc/grpc-java#4086 to make a new grpc
stream for each call?---
