[CASSANDRA-20142] Fix topology replay during bootstrap and startup, decouple Accord from TCM

• Type: Bug
• Status: Triage Needed
• Priority: Normal
• Resolution: Unresolved
• Platform: All
• Assignee: Alex Petrov
• Reporter: Alex Petrov

Authors

Alex Petrov

• Created: 12/Dec/24 15:27
• Updated: 12/Dec/24 15:29

Description

Includes multiple changes, primary ones:

• Removed nodes now live in TCM, no need to discover historic epochs in order to find removed nodes
• CommandStore <-> RangesForEpochs mappings required for startup are now stored in journal, and CS can be set up without topology replay
• Topology replay is fully done via journal (where we store topologies themselves), and topology metadata table (where we store redundant/closed information)
• Fixed various bugs related to propagation and staleness
• TCM was previously relied on for "fetching" epoch: we can not rely on it as there's no guarantee we will see a consecutive epoch when grabbing Metadata#current
• Redundant / closed during replay was set with incorrect ranges in 1 of the code paths
• TCM was contacted multiple times for historical epochs, which made startup much longer under some circumstances

Issue Links

• links to: Accord PR
• links to: Cassandra PR