4.0.15

Fixed

• Improvements to the Raft implementation, to retain commit safety and liveness despite message loss (#6016).

Added

• Added 2 new log lines which may be helpful diagnostics in production deployments, both including a new [rollback] tag.
• [rollback] ... Dropping conflicting branch may be emitted after network partitions, and indicates that some Pending (non-committed) transactions have been lost. This is expected, but worth investigating if it occurs regularly - it is a sign of elections impacting service availability.
• [rollback] ... Ignoring conflicting AppendEntries could also be emitted after a network partition, but should be reported to the CCF development team. It is a sign of an unexpected execution path, which could lead to loss of liveness (inability to advance commit).

Dependencies

• The CCF Python package now requires cryptography 42.*