We have significant usage for years but this is the first time we observed this error
Caused by: com.datastax.driver.core.exceptions.ProtocolError: An unexpected protocol error occurred on host /10.x.x.x:9042. This is a bug in this library, please report: Invalid or unsupported protocol version (76); supported versions are (3/v3, 4/v4, 5/v5-beta) at com.datastax.driver.core.Responses$Error.asException(Responses.java:126)
According to this documentation, this error means
Indicates that the contacted host reported a protocol error. Protocol errors indicate that the client triggered a protocol violation (for instance, a QUERY message is sent before a STARTUP one has been sent). Protocol errors should be considered as a bug in the driver and reported as such.
So if this is a bug in the driver, I would like to ask the following questions
1. How can we troubleshoot and help you fix this bug?
2. Any approach or configuration we should use to prevent this error from happening in the future
Should we upgrade the driver or anything suggested?
We are using Cassandra 3.x and datastax driver 3.x and I don't think it's easy to reproduce this error.