[CASSANDRA-16374] Restore check for consistent native protocol versions for connection

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 4.0-rc1, 4.0
• Component/s: Messaging/Client
• Labels: protocolv5
• Bug Category: Correctness - API / Semantic Implementation
• Severity: Normal
• Complexity: Normal
• Discovered By: Code Inspection
• Platform: All
• Impacts: Clients
• Since Version: 4.0-beta4

Source Control Link

https://github.com/apache/cassandra/commit/a0441eb66b1976865c105069e9964104720db7fb

Test and Documentation Plan

New unit test covering all supported protocol versions. Protocol spec to be finalized in CASSANDRA-14688.

• Assignee: Sam Tunnicliffe
• Reporter: Sam Tunnicliffe

Authors

Sam Tunnicliffe

Reviewers

Michael Semb Wever

• Created: 05/Jan/21 14:30
• Updated: 22/Jan/21 14:03
• Resolved: 22/Jan/21 14:03

Description

In protocol v4 and earlier, the frame header is checked during deserialization to ensure that the version matches the one negotiated for the connection.
The original intention was to remove this version id from the frame (renamed to envelope in v5) header. However, there is value in keeping this check as well as the the one for the beta flag, so it remains in the frame/envelope format. The validation itself however, was removed by some refactoring as part of CASSANDRA-15299 and should be added back for all protocol versions before finalizing v5 and cutting a release candidate. The text detailing its removal also remains in the proposed spec update attached to CASSANDRA-14688, which also needs to be updated.