master
2 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Chris Lu
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15f4a97029 |
fix: improve raft leader election reliability and failover speed (#8692)
* fix: clear raft vote state file on non-resume startup The seaweedfs/raft library v1.1.7 added a persistent `state` file for currentTerm and votedFor. When RaftResumeState=false (the default), the log, conf, and snapshot directories are cleared but this state file was not. On repeated restarts, different masters accumulate divergent terms, causing AppendEntries rejections and preventing leader election. Fixes #8690 * fix: recover TopologyId from snapshot before clearing raft state When RaftResumeState=false clears log/conf/snapshot, the TopologyId (used for license validation) was lost. Now extract it from the latest snapshot before cleanup and restore it on the topology. Both seaweedfs/raft and hashicorp/raft paths are handled, with a shared recoverTopologyIdFromState helper in raft_common.go. * fix: stagger multi-master bootstrap delay by peer index Previously all masters used a fixed 1500ms delay before the bootstrap check. Now the delay is proportional to the peer's sorted index with randomization (matching the hashicorp raft path), giving the designated bootstrap node (peer 0) a head start while later peers wait for gRPC servers to be ready. Also adds diagnostic logging showing why DoJoinCommand was or wasn't called, making leader election issues easier to diagnose from logs. * fix: skip unreachable masters during leader reconnection When a master leader goes down, non-leader masters still redirect clients to the stale leader address. The masterClient would follow these redirects, fail, and retry — wasting round-trips each cycle. Now tryAllMasters tracks which masters failed within a cycle and skips redirects pointing to them, reducing log spam and connection overhead during leader failover. * fix: take snapshot after TopologyId generation for recovery After generating a new TopologyId on the leader, immediately take a raft snapshot so the ID can be recovered from the snapshot on future restarts with RaftResumeState=false. Without this, short-lived clusters would lose the TopologyId on restart since no automatic snapshot had been taken yet. * test: add multi-master raft failover integration tests Integration test framework and 5 test scenarios for 3-node master clusters: - TestLeaderConsistencyAcrossNodes: all nodes agree on leader and TopologyId - TestLeaderDownAndRecoverQuickly: leader stops, new leader elected, old leader rejoins as follower - TestLeaderDownSlowRecover: leader gone for extended period, cluster continues with 2/3 quorum - TestTwoMastersDownAndRestart: quorum lost (2/3 down), recovered when both restart - TestAllMastersDownAndRestart: full cluster restart, leader elected, all nodes agree on TopologyId * fix: address PR review comments - peerIndex: return -1 (not 0) when self not found, add warning log - recoverTopologyIdFromSnapshot: defer dir.Close() - tests: check GetTopologyId errors instead of discarding them * fix: address review comments on failover tests - Assert no leader after quorum loss (was only logging) - Verify follower cs.Leader matches expected leader via ServerAddress.ToHttpAddress() comparison - Check GetTopologyId error in TestTwoMastersDownAndRestart |
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Chris Lu
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753e1db096 |
Prevent split-brain: Persistent ClusterID and Join Validation (#8022)
* Prevent split-brain: Persistent ClusterID and Join Validation - Persist ClusterId in Raft store to survive restarts. - Validate ClusterId on Raft command application (piggybacked on MaxVolumeId). - Prevent masters with conflicting ClusterIds from joining/operating together. - Update Telemetry to report the persistent ClusterId. * Refine ClusterID validation based on feedback - Improved error message in cluster_commands.go. - Added ClusterId mismatch check in RaftServer.Recovery. * Handle Raft errors and support Hashicorp Raft for ClusterId - Check for errors when persisting ClusterId in legacy Raft. - Implement ClusterId generation and persistence for Hashicorp Raft leader changes. - Ensure consistent error logging. * Refactor ClusterId validation - Centralize ClusterId mismatch check in Topology.SetClusterId. - Simplify MaxVolumeIdCommand.Apply and RaftServer.Recovery to rely on SetClusterId. * Fix goroutine leak and add timeout - Handle channel closure in Hashicorp Raft leader listener. - Add timeout to Raft Apply call to prevent blocking. * Fix deadlock in legacy Raft listener - Wrap ClusterId generation/persistence in a goroutine to avoid blocking the Raft event loop (deadlock). * Rename ClusterId to SystemId - Renamed ClusterId to SystemId across the codebase (protobuf, topology, server, telemetry). - Regenerated telemetry.pb.go with new field. * Rename SystemId to TopologyId - Rename to SystemId was intermediate step. - Final name is TopologyId for the persistent cluster identifier. - Updated protobuf, topology, raft server, master server, and telemetry. * Optimize Hashicorp Raft listener - Integrated TopologyId generation into existing monitorLeaderLoop. - Removed extra goroutine in master_server.go. * Fix optimistic TopologyId update - Removed premature local state update of TopologyId in master_server.go and raft_hashicorp.go. - State is now solely updated via the Raft state machine Apply/Restore methods after consensus. * Add explicit log for recovered TopologyId - Added glog.V(0) info log in RaftServer.Recovery to print the recovered TopologyId on startup. * Add Raft barrier to prevent TopologyId race condition - Implement ensureTopologyId helper method - Send no-op MaxVolumeIdCommand to sync Raft log before checking TopologyId - Ensures persisted TopologyId is recovered before generating new one - Prevents race where generation happens during log replay * Serialize TopologyId generation with mutex - Add topologyIdGenLock mutex to MasterServer struct - Wrap ensureTopologyId method with lock to prevent concurrent generation - Fixes race where event listener and manual leadership check both generate IDs - Second caller waits for first to complete and sees the generated ID * Add TopologyId recovery logging to Apply method - Change log level from V(1) to V(0) for visibility - Log 'Recovered TopologyId' when applying from Raft log - Ensures recovery is visible whether from snapshot or log replay - Matches Recovery() method logging for consistency * Fix Raft barrier timing issue - Add 100ms delay after barrier command to ensure log application completes - Add debug logging to track barrier execution and TopologyId state - Return early if barrier command fails - Prevents TopologyId generation before old logs are fully applied * ensure leader * address comments * address comments * redundant * clean up * double check * refactoring * comment |