Date: 2026-05-29
Time: 13:52
I have enough from the observations to give a thorough explanation. Let me work with what's already gathered.
raft-consensus/raft.py:makeappend_entries — See how the full log suffix is sliced for replication; this is the hot path that snapshots would optimizeraft-consensus/raft.py:handleappendentries — The log consistency check indexes directly into self._log, which would break after truncationwrite-ahead-log/wal.py — Compare its truncate() and _rotate() methods as patterns for log lifecycle managementlog-structured-merge-tree/lsm.py — The compact() method shows a complete compaction implementation with tombstone removal in this same codebaseraft-installsnapshot-rpc — The Raft paper's Section 7 describes the InstallSnapshot RPC that would complement log truncation---
raft-log-never-shrinks — self._log in RaftNode is append-only: no method ever removes entries, so it grows monotonically with client requestsraft-log-direct-indexed — Log entries are accessed by log index as a direct array index (self.log[prevlog_index]), which assumes all entries from index 0 onward are present in memoryraft-no-state-machine-apply — lastapplied is tracked but never used to actually apply commands to a state machine, making snapshotting impossible without first implementing application logicwal-has-truncation-raft-does-not — The WAL module provides explicit truncate(uptoseq) and file rotation; the Raft module has no equivalent, despite both being append-only log abstractionsraft-sentinel-entry-assumption — The log is initialized with a sentinel LogEntry(term=0, index=0) at position 0, and multiple methods depend on this entry always being present at self._log[0]