Rongsong Shen
007bf0c403
After reserve-lsn-0 (oldest retained WAL entry = lsn 1 on a fresh cluster), a freshly-joined empty standby (applied_lsn=0) hit the snapshot-fallback branch 'standby_lsn < oldest_wal_lsn' (0 < 1) and was sent a non-existent snapshot instead of streaming — so the own-term NOOP (lsn 1) never replicated, committed_lsn stayed 0, the own-term gate (writable_lsn=1) stayed closed, and standbys kept empty WALs. Live evidence: ha_dispatch_repl_action_for_standby: standby[0] lsn=0 < oldest_wal_lsn=1 -> requesting snapshot transfer The snapshot fallback should fire only when the standby's NEXT-needed entry (standby_lsn+1) has been GC'd below the oldest retained entry. Fix the boundary to 'standby_lsn + 1 < oldest_wal_lsn' in ha_evaluate_repl_action (and the parallel dead repl_needs_snapshot predicate). An empty standby (next-needed=1, oldest=1) now STREAMs lsn 1 -> acks -> committed_lsn 0->1 -> own-term gate opens -> standbys receive the WAL. Snapshot still fires for genuinely GC'd-behind standbys (standby_lsn+1 < oldest). No underflow (oldest=0 -> 1<0 false). Pre-reserve-lsn-0 this off-by-one was masked by oldest_wal_lsn=0 (0<0 false). TDD: test_empty_standby_fresh_cluster_streams_not_snapshot (RED->GREEN); snapshot + heartbeat pins strengthened to assert SEND_SNAPSHOT only for genuinely GC'd standbys and STREAM_WAL at the empty/boundary case. Full controller suite green under ASAN; commit engine / streamer / apply path / wire untouched. |
||
|---|---|---|
| .. | ||
| autoscaler | ||
| controller | ||
| docs | ||
| frontend | ||
| include | ||
| lib | ||
| nixSupport | ||
| scheduler | ||
| schema | ||
| tools | ||
| worker | ||
| build | ||
| flake.lock | ||
| flake.nix | ||
| meson.build | ||
| meson.options | ||