ha_send_snapshot_to_standby ignored the network send's return value in its
chunk loop, silently truncating a transfer on a mid-stream error while still
logging "complete" (bug-1386). Fixing the silent drop exposed a second,
independent bug in the same pipeline: ha_handle_snapshot_chunk appended
received chunks in arrival order instead of at their wire-carried
chunk_offset, so out-of-order delivery across the vtask pool corrupted the
reassembled file even though every chunk's bytes were individually correct
(bug-1389). Fixed by checking every fallible call in the send loop and
switching the receiver to pwrite-at-offset with a count-based completion
tracker.
Adds snapverify/snapdiff xce_test commands (offline checkpoint-file
structural validator and byte-level comparator) used to diagnose bug-1389 and
kept as standing diagnostic tools for future snapshot-transfer triage.
g_drive_async_configpush_offload flipped back ON after both fixes, validated
via 6-round chaotic + 3/3 force-snapshot soak (raft-drive-async task 3.3).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SDWVNQLKxqTVHh42cH7rV3
Root cause: peer_ctrl_msg_handler held ep->dispatch_inflight incremented
across the entire peer_ctrl_dispatch_to_pool call, including its inline
fallback (the common cold-start shape when ha->pool isn't wired yet). That
inline body can reach raft_cb_become_follower, which -- now that
cluster_init_phase2 ran synchronously earlier in the same call chain and
wired the pool -- tears down its own loser vote-ep (the very ep whose reply
triggered this call) via the deferred path (vote_ep_teardown_async), whose
endpoint_mark_tearing_down spins waiting for dispatch_inflight==0 on that
SAME ep. That count is held only by this exact call, on this exact thread,
and can't reach 0 until the spin itself returns -- a permanent self-deadlock.
Confirmed live via a gdb thread backtrace: added a GDB_WRAP debug seam to
run-ha-soak.sh (launches a named node directly under `gdb --batch` so it
becomes ptrace-legal as gdb's own direct child under yama scope 1, bypassing
a live-attach restriction), then SIGINT to gdb once the log went stale for a
bounded interrupt + full backtrace. The frame dump showed pool=0x0 at
peer_ctrl_dispatch_to_pool, and the same ep pointer in the nested
vote_ep_teardown_async -> endpoint_mark_tearing_down frame, spinning on
sched_yield().
Fix: moved the dispatch_inflight release into peer_ctrl_dispatch_to_pool
itself, at the exact right point per exit path -- released BEFORE calling
the inline body on every fallback path (pool==NULL, OOM, enqueue failure),
since io_worker is single-threaded and the inline path never enqueues
anything (no pool-worker race left to protect against once inline execution
is committed to); released only AFTER the non-blocking enqueue completes on
the success path, preserving the original protection for the genuinely
concurrent pool-worker case.
New unit test test_vep_self_teardown_does_not_deadlock uses a bounded
pthread_timedjoin_np so a regression fails loud instead of hanging the
suite. RED confirmed via a temporary manual revert (ETIMEDOUT) before
restoring the fix.
Live-verified with both flags ON: --force-snapshot soak (the exact repro
shape) completes without hanging across repeated runs, confirms real
snapshot installs, zero divergence, zero job loss; a 6-round --chaotic soak
also passed clean; full controller suite green throughout.
g_drive_async_snapshot_offload and g_drive_async_peerctrl_dispatch_enabled
now default ON in production, closing raft-drive-async tasks 3.1 and 3.2.
g_drive_async_configpush_offload stays OFF -- a distinct, still-open hazard
in push_config_transport_only's endpoint handling (task 3.3, unrelated to
this bug).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014dZVSx3CdBjys9BB6hqpxP
Both fixes are real and independently verified; the drive-async flags
(g_drive_async_snapshot_offload, g_drive_async_peerctrl_dispatch_enabled)
stay at their production-default OFF -- see the tasks.md session note for
why the flip itself doesn't land in this commit.
1. Snapshot-lane borrowed-endpoint hazard (task 3.2, bug-1197 family):
ha_snapshot_send_dispatch now takes endpoint_ref(ep) before submitting to
the slow lane, released on every non-lane terminal path and by
snapshot_lane_fn on completion. Reuses the general bug-1298 endpoint
refcount system (standby-ep teardown already routes through
endpoint_unref via cluster.c's endpoint_killer) -- a concurrent RDHUP
teardown can now only drop the owner's reference while a transfer is in
flight, never free the ep out from under it. New test:
test_snapshot_offload_holds_endpoint_ref_across_transfer (RED->GREEN).
2. Catch-up streamer WAL_CHECKPOINT bug (found while verifying #1 via a live
soak, pre-existing, unrelated to the drive-async flags): ha_stream_wal_
to_standby had no filter for WAL_CHECKPOINT markers -- local-only
bookkeeping that still consumes a real LSN slot via persist_write_
checkpoint_marker's own current_lsn++. It shipped one to a catching-up
standby, which correctly refused it (persist_wal_write_replicated
rejects type==WAL_CHECKPOINT) and got stuck retrying the same LSN
forever. Fixed by skipping WAL_CHECKPOINT entirely in the streamer loop,
mirroring the existing replay_wal/term-index precedent of treating
checkpoint-marker LSNs as invisible gaps. New test:
test_wal_stream_skips_checkpoint_marker (RED->GREEN).
Attempted flipping both drive-async flags ON after landing these fixes (the
"full fix, defer prod flip" decision's prerequisite -- 4.1+4.2 are green).
A 6-round --chaotic soak passed clean, but a --force-snapshot soak (a
genuinely empty node cold-start rejoin, the one scenario chaotic mode never
exercises) surfaced a THIRD, not-yet-root-caused issue: the freshly-wiped
node's own self-election appears to race cluster_init_phase2's vtask-pool
wiring, then the process hangs silently (no crash, no ASAN report) until
killed. Reverted both flags to OFF rather than ship an unproven state --
production behavior is unchanged by this commit. Full controller suite
green and both soaks (--force-snapshot, 6-round --chaotic) pass clean with
flags OFF, confirming no regression from the two logic fixes.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014dZVSx3CdBjys9BB6hqpxP
walcompare previously had no concept of a per-member compaction floor:
committed_lsn only capped the HIGH end (skip LSNs a member hasn't
caught up to yet), but the LOW end unconditionally expected every
member to hold raw WAL from LSN 1. A member that legitimately caught
up via a full-checkpoint snapshot holds no raw WAL at or below its own
checkpoint LSN by design (that range was entity-restored, not
WAL-replayed) -- so it was always flagged MISSING/divergent there,
regardless of whether the restore was correct. This is the root cause
ha-entity-snapshots task 7.1 diagnosed (committed_divergence=11 on an
otherwise-healthy soak) and raft-ha-core-safety task 5.10a's residual.
Adds member_snapshot_floor(): each member's own snap/ sibling
directory (matching the deployed <data>/wal + <data>/snap layout) is
scanned for the highest installed snap-<lsn>.{capnp,bin} file. Any LSN
at or below that member's own floor is excluded from its comparison
the same way an LSN above its own committed_lsn already is -- never
uniform/shared across members, since compaction is a per-member fact.
wc_status() gains a new "compacted" token distinct from "MISSING" so
the machine-readable report can tell the two apart.
Two new regression tests prove: (1) the floor correctly suppresses the
compacted range from comparison, and (2) it does NOT mask a genuine
divergence within the range a member still claims to hold. Caught and
fixed one bug myself before landing: the floor comparison was
off-by-one (< instead of <=), which the first test run surfaced
immediately (Expected 0 Was 1).
test_walcompare 17/17, test_ha_core_safety 28/0, test_config_repl
66/0, test_waldump 7/0 (all no-regression). Soak --selftest 17/17.
A full 69-group sweep of controller_unit_test (this spec's harness had
never been run end-to-end before) found 2 deterministic failures,
both test-only staleness against already-shipped, already-approved
production behavior from earlier in this same spec:
- test_ha_vote_gate: test_pre_vote_catch_up_denies asserted the
pre-task-5.3 unconditional in_catch_up PreVote deny. Task 5.3
(bf88681) deliberately gated that deny on primary_ctrl_fd>=0 &&
ha_heartbeat_is_fresh to fix a real round-4 election-stall — this
test's exact scenario (stale heartbeat, primary_ctrl_fd=-1) is the
case 5.3 intentionally flipped to grant. Split into
test_pre_vote_catch_up_grants_when_primary_unreachable (matches the
current contract) and test_pre_vote_catch_up_denies_while_primary_live
(preserves the original protective intent, correctly scoped).
- test_egress_filter: test_live_submit_tags_submit_lsn called the
JOB_NEW persist_job_hook_fun AFTER_EVENT hook directly, but task 5.9
(15be5d9, bug-1306 fix) made that hook's WAL_MODE_WAIT branch
notify-only, moving the real WAL append + commit barrier into
persist_submit_wal_and_commit(). 5.9 relocated 4 equivalent tests in
test_persist_hooks.c but missed this one. Now drives
persist_submit_wal_and_commit() directly, mirroring that pattern.
No production code changed. Full 69-group suite: 0 Failures, 0 ASAN
reports (independently reproduced 3x: initial sweep, implementer,
reviewer).
The term-blind ha_apply_single_entry direct-persist branch (carried
forward from task 2.4) is unreachable with a real non-zero term in any
current production path: its only trigger, raft_send_append_entries,
has zero production call sites (library simulator only). Both real
senders (repl_broadcast, ha_stream_wal_to_standby) always emit a
non-zero term for a present LSN. Documents this in ha.c and design.md
rather than structurally retiring a dormant path (YAGNI), with an
explicit flag for future re-evaluation if a heartbeat-driver task ever
wires up raft_send_append_entries.
Adds two regression pins: restart preserves (term,lsn) identity
(replay_wal already reconstructs the term index via record_entry_term),
and real senders never produce the term-blind wire shape.
test_ha_core_safety 28/0, no regression, no ASAN reports.
Integration test proves the guarantee tasks 2.3/2.4 hardened in
isolation (synthetic fault injection on the streamer) also holds
end-to-end over two real persist_t/WAL instances through the real
production ingest seam (ha_apply_wal_catchup_entry). Covers live
in-term replication and cross-term catch-up: no term==0 sourced for a
live entry, no non-empty entry ever lands as PLEN=0, standby persists
the entry's stored term (not the AE header's leader-current-term,
the bug-1067 split), and walcompare reports a clean committed prefix.
test_ha_core_safety 26/0, no regression, no ASAN reports.
Adds checkpointTerm (@6, append-only) to the SnapshotTransfer wire
message. The leader stamps it via persist_entry_term(p, checkpoint_lsn)
when sending a snapshot; the standby reconciles it into its own
per-LSN term index (persist_reconcile_checkpoint_term) right after
persist_load_snapshot succeeds, before applied_lsn advances. This
authoritatively overwrites any stale local term a divergent
pre-snapshot entry left at the checkpoint LSN, closing the gap task
3.1's RED test proved (Expected 7 Was 3 -> now passes). Transport
stays persist_t-free; the reconcile lives in persist.c per the
existing dependency direction. Decode is auto-generated via capnp
mapname; only the hand-rolled encode path (request.c/typemap.h, needed
for the raw snapshot payload) required a matching manual update.
test_ha_core_safety 25/0, test_config_repl 66/0, no ASAN reports.
ha_handle_snapshot_chunk/persist_load_snapshot advance checkpoint_lsn,
current_lsn, and applied_lsn on snapshot install but never touch the
per-LSN term index, so a divergent pre-snapshot entry's stale local
term survives the install unreconciled. New test proves the gap
(Expected 7 Was 3); fix lands in task 3.2.
ha_handle_snapshot_chunk now logs whether a received checkpoint was
fully entity-restored or was a legacy position-only file (INFO level,
framed as an expected rollout state -- never an error, per design.md).
The rc-gates-applied_lsn control flow is byte-for-byte unchanged from
task 5.2 (confirmed by review) -- this task is purely additive
observability, matching design.md's own note that this call site
"needs no change" once persist_load_snapshot's gate is correct.
New test drives the legacy path end-to-end through the real production
handler (rc==0, file renamed, applied_lsn advances to the legacy LSN).
This completes the integration layer -- write path (jobs+queues),
restore-before-advance read path, and the production wiring are all in
place and independently reviewed. Only validation tasks remain (7.1
chaotic soak, 8.1 rollback compatibility).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
Replaces the naive task-5.1 stopgap with the real restore contract:
detects legacy vs entity-bearing checkpoints by remaining file size;
restores every job then every queue status via restore_job/
restore_queue_state, in file order, with bounds-checked length-prefixed
reads; only after every entity restores successfully does
current_lsn/checkpoint_lsn commit to the checkpoint's position. Every
failure path (bounds check, decode, restore error, unrecognized
format_version) returns before that single commit point -- position is
provably untouched on failure, never partially advanced.
Also fixes the pre-existing restore_job decode leak (job.c): job_init
deep-copies submit (never nulled) and MOVE_PTRs allocs/pidinfo/
pend_reasons (nulled on the one path that runs) -- free_Job(&j) is safe
unconditionally on every reachable return path (EEXIST early-return,
create_job success, create_job failure), verified against the exact
generated free_*_ptr null-check guards.
Two pre-existing test_config_repl.c wire-protocol tests needed their
synthetic garbage snapshot bodies updated to a well-formed empty-entity
tail, since load_snapshot now genuinely parses past the legacy header
(previously ignored); their actual assertions (chunk-reassembly
correctness) are unchanged.
This is the exact function/contract that caused task 2.2's rejection
(position advancing before restore validated). Independent review
traced the memory-safety fix through the generated capnp code field-by-
field, confirmed the test_config_repl.c change doesn't weaken any
assertion, and confirmed restore_queue_state's ENOENT-aborts-the-whole-
checkpoint behavior is faithful to design.md's unconditional contract
(flagged as a watch-item for task 7.1's soak, not a defect).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
Extends persist_load_snapshot's public signature with an
out_entities_restored bool*, per design.md's documented contract. The
static load_snapshot function -- the real restore logic -- is completely
untouched (still today's watermark-only implementation, byte-identical
to before this task); only a thin wrapper was added that naively maps
*out_entities_restored = (rc==0), deliberately scaffolding so the 3 new
RED tests fail for genuine reasons rather than accidentally passing.
ha_handle_snapshot_chunk's sole call site gets a mechanical
declare-and-pass update -- confirmed inert, never reads the new
out-param (task 6.1's job).
Three tests against persist_load_snapshot directly (unlike prior tasks'
tests, which deliberately stayed on the raw-byte-parsing side to avoid
this exact function): restore-before-advance (fails at the job-lookup
assertion -- nothing is ever restored today), corrupted-entity-leaves-
position-unchanged (fails at rc!=0 -- today's code ignores the corrupted
section entirely, since load_snapshot never reads past the legacy
header), legacy-file-reports-position-only (fails at entities_restored==
false -- the naive wrapper claims restoration for every rc==0 case,
including legacy files).
This is the exact function/call site that caused task 2.2's rejection
(a live position-advances-before-restore-validates hazard). Independent
review verified load_snapshot's body is byte-identical to commit
d52eb94, the wrapper does nothing beyond the naive mapping, and ha.c's
change never reads the new out-param anywhere -- no repeat of that
mistake here.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
A checkpoint file whose position matches an in-flight peer transfer
(task 4.1's snapshot_inflight_lsn[]) must survive rotate_snapshots even
when snap_keep_n would otherwise delete it. Genuinely fails today (file
removed, access() returns -1) since rotate_snapshots has no awareness of
in-flight transfers yet.
Executed directly (no subagent dispatch) per the hybrid execution-mode
decision -- small, single-file, isolated test.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
Adds snapshot_inflight_lsn[MAX_HA_CANDIDATES] to ha_state_t, alongside the
existing snapshot_inflight[] flag it mirrors exactly: set to the
checkpoint's LSN at ha_snapshot_send_dispatch before a transfer's first
byte goes out, cleared to 0 at every completion/failure path
(snapshot_lane_fn's normal completion, and all 3 early-return failure
sites: malloc failure, slowlane dedup-refuse, slowlane submit failure).
This is the foundation task 4.3 will consult from rotate_snapshots to
avoid deleting a checkpoint file a peer is still mid-transfer reading
from -- the one genuinely new retention guard this feature needs (the
existing write_snapshot-before-trim_wal_segments sequencing already
satisfies the WAL-trim side of Requirement 3).
Proven via a new gated unit test (test_ha_liveness.c) that observes the
tracked LSN mid-flight while the send body is parked at a test gate, not
just before/after -- confirms the lifecycle ordering, not just the
endpoints.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
Queue's (name, status) round-trip through write_snapshot's raw on-disk
bytes -- a plain fixed record (no capnp; queue definitions are
config-owned, only runtime admin status is WAL/snapshot-tracked, per
design.md's corrected queue model). Fails today (Expected 4 Was 0) since
write_snapshot still hardcodes queue_count=0 from task 2.2's placeholder.
Does not call persist_load_snapshot, following task 2.2's established
raw-byte-parsing pattern.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
write_snapshot now Cap'n-Proto-encodes every retained job under nested
table+per-entity RTTI_LOCK_READ (table lock alone does not exclude a
concurrent per-entity writer -- design.md's central correctness finding),
appends length-prefixed job frames after a new format_version marker, and
fixes a previously-unchecked fdatasync return. Any failure anywhere in the
path (encode, write, sync) discards the whole checkpoint -- no partial
file at the final path, proven by a real mid-encode-loop fault-injection
test (forces one specific job's encode to fail among N, asserts nothing
survives).
Also fixed two pre-existing bugs in task 1.1's test fixture: terminal-state
seeded jobs need a non-zero finish_time or job_should_retain's retention
window silently excludes them from any checkpoint; the fixture needs
xstring_table_init or every seeded job's submit/start_info silently
decodes as NULL.
Round 1 of this task also touched load_snapshot/persist.h to make the
round-trip tests pass end-to-end, but review caught a live hazard: it
advanced current_lsn/checkpoint_lsn BEFORE the entity-decode loop ran, so
a decode failure still left the position advanced -- reachable today
through the unmodified ha_handle_snapshot_chunk production path, not
hypothetical. Remediated by fully reverting load_snapshot/persist.h to
byte-identical pre-task-2.2 state and rewriting the round-trip tests to
parse write_snapshot's raw on-disk bytes directly (read_Job/decode_Job)
instead of round-tripping through persist_load_snapshot -- proves the
write side without depending on load_snapshot, which stays task 5.2's
scope entirely, not started here.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
Three tests against the current sentinel-only write_snapshot/load_snapshot:
job content round-trip and concurrent-mutation-not-torn genuinely FAIL
(RED) since no entity content is written today; write-failure-discard
already passes (write_snapshot's open()-failure path already discards
correctly) -- flagged transparently as a GREEN-from-day-one regression
guard rather than faked RED, per real fault injection (directory removal
-> genuine ENOENT).
Carries forward two notes for task 2.2: fdatasync's return value is
currently unchecked in write_snapshot (persist.c:1505), and a mid-encode-
loop fault-injection test should be added once the per-job encode loop
exists.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
Adds the ha-entity-snapshots Kiro spec (requirements, design, research,
tasks) for task 5.10a / raft-ha-core-safety: making the HA checkpoint an
actually-restorable copy of committed job/queue state instead of a
position-only sentinel, closing the residual chaotic-soak divergence gap.
Task 1.1 (foundation): reusable test fixture snapent_make/snapent_teardown
in a new test_persist_snapshot_entities.c, seeding N jobs (varying state)
and M queues (varying status) into a real persist_t+cluster_t for later
write/load/rotation-guard tests to build on. Build clean; new suite 1/1;
regression spot-checks (test_persist_hooks 19/19, test_commit_barrier_reply
22/22) clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
A dead primary's control fd RDHUPs faster than an election settles. The 5.6
guard only drops an RDHUP while the role is instantaneously CTRL_ELECTING/
prevote; an RDHUP landing in the gap after a lost election (role briefly back
to CTRL_STANDBY) re-triggers a fresh ha_begin_failover -> PreVote -> real
election (term++). One bump per RDHUP -> unbounded escalation under a sustained
cadence (observed round 4: 48 begin_failovers, terms 6->24, round overran the
harness window).
Fix: ha_state_t.last_failover_ms (atomic) stamped at ha_begin_failover;
ha_on_primary_ctrl_fd_rdhup drops an RDHUP within 2*election_timeout_ms of the
last trigger (closes the dead fd, returns) so the election's own jittered retry
(5.7) runs without the external RDHUP cadence adding term bumps. First trigger
never debounced; genuine loss still fails over, at most once per window.
Validation: unit-proven — test_rdhup_within_cooldown_is_debounced (recent
last_failover -> stays CTRL_STANDBY) vs test_rdhup_single_node_reaches_primary
(last_failover=0 -> CTRL_PRIMARY) is a differential proof. Soak: 10/10 elect,
terms 4->14 bounded, begin_failover 14/14/12 (was 48), committed_job_loss=0, no
regression. The stochastic storm did not recur this run (debounce fired 0x), so
soak-reproduction of the storm is still pending; the mechanism rests on the
unit test. Election suites green (rdhup 8/0, prevote 12/0, core_safety 24/0,
election 28/0, failover_prevote 6/0).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
raft-apply-decoupling item #1 (down payment). xce_run_hooks returns only the
LAST-registered hook's rc, so a later JOB AFTER_EVENT subscriber (sched/
apiserver) returning 0 clobbered persist_job_hook_fun's commit -ETIMEDOUT.
handle_jobsubmit then replied 'jobsubmit ok' for an entry that never reached
majority, and a new-term leader legally discarded it (committed-job-loss,
Commit Durability violation).
- persist.c/.h: new persist_submit_wal_and_commit(p, jlist) — the explicit raft
step (WAL append + majority-commit barrier) returning the commit verdict
directly. persist_job_hook_fun's WAL_MODE_WAIT branch is now a no-op.
- job.c handle_jobsubmit: call the explicit step, read commit_rc DIRECTLY,
reject on <0 before firing the now notification-only AFTER hook
(canonical commit -> notify -> reply).
- tests: +test_job_hook_new_is_notify_only regression pin; 4 hook tests
relocated to drive the explicit step. persist_hooks 19/0, e2e_hooks 3/0,
commit_barrier_reply 22/0, commit_durability 38/0.
Proven: 10-round chaotic soak committed_job_loss 5 -> 0 (same election code).
Residual soak FAILs (divergence catch-up lag + a round-4 election-escalation
tail) are NOT job loss — tracked as task 5.10.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JDYFbrgyDHbvNYcxApKhrX
The io_worker freed an endpoint (endpoint_killer, cluster.c) on connection
teardown while the vtask dispatcher concurrently read ep->busy
(endpoint_is_task_blocked, netio.c) on a queued vtask — a heap-use-after-free
that ABORTed a controller mid-chaotic-soak (round 4), dropping the cluster
below quorum so no primary could be elected.
Replace the accumulation of ad-hoc ep-lifetime patches (bug-1282 lockless busy,
bug-1197 dispatch_inflight drain + deferred teardown vtask) with one principled
invariant: an endpoint lives until its reference count reaches 0.
- endpoint_t.refcnt (_Atomic) + heap_alloc flag; endpoint_get starts a heap ep
at refcnt=1 (the owner ref).
- endpoint_ref/endpoint_unref: the last unref fini's + frees a heap ep.
Embedded eps (client ctx->ep, heap_alloc=0) are never freed here — their
container owns them — so a vtask-balanced ref/unref pair is a safe no-op.
- vtask_enq takes a per-vtask ref on the bound ep BEFORE publishing the task to
the dispatcher; run_task / taskq_item_killer release it. So the dispatcher can
read ep->busy on any queued vtask without the ep being freed underneath it.
- every HEAP-ep teardown site (endpoint_killer, handle_endpoint_error, the
vote/prevote connect-fail paths, the vote-ep loser/teardown paths, the standby
reconnect/eviction paths) now drops its owner ref via endpoint_unref instead of
raw endpoint_fini+free. Several of those also leaked the ep struct before
(endpoint_fini-only); unref fixes the leak too.
Validation: controller_unit_test 182 tests / 0 failures (test_ha_vep_teardown
updated — its OFF-path test asserted the old struct leak, now fixed). 6-round
ASAN chaotic soak: ZERO AddressSanitizer reports, ctrl-3 no longer crashes at
round 4, all 6 rounds elect at bounded terms. (The pre-existing iomgr_fini ->
SSL_CTX_free abort under openssl 3.6 in the aggregate test binary is unrelated.)
Note: with the crash gone, the soak now reaches rounds 4-6 for the first time and
surfaces a SEPARATE, pre-existing committed-job-loss/divergence (the bug-795/828
failover catch-up gap; ha-commit-durability domain) — not a refcount regression
(ASAN clean; rounds 1-3 are loss-free).
The per-campaign election watchdog was armed with a FIXED election_timeout_ms
(raft_start_election -> on_schedule_timeout -> raft_cb_schedule_timeout). Under
cold-connection churn a just-restarted survivor opens a fresh TCP+SSL endpoint
per vote round, so its single needed grant can land a hair AFTER a constant
deadline on EVERY campaign -- a resonance: the campaign times out, the term
re-escalates, and the now-stale grant is dropped (DropStaleResponse). Forever.
Terms climb unbounded; the freshest survivor never tallies quorum. This is the
final round-4 chaotic-soak election-liveness stall.
Fix (Ongaro thesis 3.4): re-randomize the watchdog per campaign to the canonical
[T, 2T] interval in the HA adapter, so some campaign's deadline falls AFTER its
grant RTT and the grant lands in-window. Done in raft_cb_schedule_timeout so the
pure (sim-tested) raft library stays deterministic. Independent of
election_jitter_max_ms (which tunes only the sub-second startup/stagger jitter)
so it spreads even when jmax is small/0; never below the configured floor so
genuine-loss failover is not sped up past election_timeout_ms.
Preserves Election Safety (no change to term/vote/DropStaleResponse logic).
new ha_jittered_election_delay() helper + 2 unit tests (RED verified: stubbing
jitter to 0 fails test_5_7_campaign_timeout_is_randomized with the resonance
message; PIN guards floor + modulo-by-zero). Suite: 24 Tests / 0 Failures.
After 5.5 let the freshest survivor win PreVote and ENTER the real election,
round 4 still stalled: the dead primary's control fd keeps RDHUP'ing on a
deterministic ~15s cadence, and ha_on_primary_ctrl_fd_rdhup's 5.2 suppress only
catches CTRL_STANDBY — so an ELECTING node fell through to ha_begin_failover and
restarted a fresh PreVote, preempting its own in-progress real election. Every
cycle bumped the term (21->25->28->29...) and kept two survivors dueling in
lockstep, defeating the jittered election-timeout tiebreak.
Guard the RDHUP entry: if role==CTRL_ELECTING or a PreVote round is in progress,
close the dead control fd and return WITHOUT restarting failover — let the
in-progress round finish or time out (its election timeout is jittered, which
desynchronizes the duel so one survivor wins). A node not currently electing
still takes the normal 5.2-suppress / genuine-loss failover path.
RED+PIN in test_ha_core_safety.c (22 Tests / 0 Failures): CORE RED — CTRL_ELECTING
+ RDHUP must not start a new PreVote (Expected 0 Was 1 on baseline); PIN — genuine
loss (STANDBY, not electing) still fails over. Preserves Election Safety, 5.2
suppression, and genuine-loss liveness. Re-running 7.2.
Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019dbTHR9CsEYK9RsqmQpQpC
The round-4 election stall surfaced by the 7.2 soak (bug-1272): after several
overlapping kills the only fully-up-to-date node is killed and the two survivors
are both restarted-and-lagging (in_catch_up=1) with no live primary left to catch
up FROM — so the flag never clears. Each holds the full committed prefix and is a
SAFE candidate, yet raft_cb_vote_eligible denied ALL PreVotes while in_catch_up
UNCONDITIONALLY, so they mutually denied and the election deadlocked forever.
Gate the in_catch_up deny on a LIVE primary (primary_ctrl_fd>=0 &&
ha_heartbeat_is_fresh), mirroring the heartbeat-fresh deny one block up. The
deny's purpose is to avoid disrupting a primary that is actively replicating to
us; once the primary is unreachable, raft_log_ok (already applied in Step 2 of
raft_on_pre_vote_request, before this callback) guarantees the candidate's log
>= ours, so granting a fresher candidate is safe (Leader Completeness preserved).
Adds 3 cases to test_ha_core_safety.c driving the real raft_on_pre_vote_request:
CORE RED (catching-up survivor + primary gone must GRANT a fresh candidate),
PIN (still DENY while a live primary feeds it), PIN (STALE candidate still DENIED
by logOk). test_ha_core_safety 20 Tests / 0 Failures; 5.1/5.2 unaffected.
Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019dbTHR9CsEYK9RsqmQpQpC
Add three Phase-5 cases to test_ha_core_safety.c pinning the spurious-failover
root cause (research.md §"Phase 4/5"):
- CORE RED test_5_1_spurious_failover_suppressed_while_primary_alive: a
control-channel flap (transient RDHUP) while a current-term primary is alive
(fresh heartbeat) must NOT launch a PreVote failover. FAILs on baseline
(Expected 0 Was 5) — the RDHUP-initiation path (ha_on_primary_ctrl_fd_rdhup
-> ha_begin_failover -> ha_start_prevote_async synchronous branch) has no
ha_heartbeat_is_fresh guard, unlike the deferred ha_failover_stagger_fn path.
GREEN when task 5.2 adds that guard.
- LIVENESS test_5_1_genuine_loss_elects_and_advances_term: genuine loss (stale
heartbeat) still launches a real failover; a failed round re-arms; rapid
rounds advance the term. Guards 5.2 against over-suppression (Req 6.1/6.2/6.3).
- SAFETY test_5_1_election_safety_one_primary_per_term: two candidates contest
the same term; the real handle_request_vote grants at most one vote per term
(A=3/B=0), so at most one committing primary per term. Falsifiable Election
Safety check mapped to raft/raft.tla (Req 4.1/4.3).
Deterministic (no sleeps; clock reads only), c==NULL unit-test mode, clean
ha_fini teardown. test_ha_core_safety suite: 17 Tests / 1 Failure (the
intended RED); all 2.x/4.x/seam cases still pass; no new ASAN leaks.
Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019dbTHR9CsEYK9RsqmQpQpC
Root-cause source fix: ha_stream_wal_to_standby reads the entry body via
stream_read_entry_body (bounded retry max 4, no sleep); on persistent short
pread/malloc-fail it fails loud + ABORTS the stream (flush valid prefix,
drop unreadable entry, -EIO) instead of shipping PLEN=0. Incomplete stream
re-driven by ACK-driven catch-up. With the 2.2 guard this closes the live
cross-term payload-loss divergence. 2.3 CORE RED -> GREEN (fail-loud: no
empty persisted; + retry-recover test ships full 64). Term-blind structural
retirement deferred to 6.2 (empty-over-full safety enforced by 2.2 guard +
pinned). 12/12 core suite; siblings green; no regression introduced.
Phase 2 complete.
Minimal XCE_TESTING fault-injection seam in ha_stream_wal_to_standby
(NULL/production-inert) forces a short body read on a cross-term entry.
CORE RED proves the streamer ships PLEN=0 for a full (source_len=64)
cross-term entry: instrumentation source_len=64 SEND_len=0 RECV_len=0 ->
loss is SEND-side (answers task 1.3's open send-vs-transitive question).
2 honest pins (term-blind route guarded by 2.2; below-tip fence). 11
tests/1 RED; production xce_controller links clean without the seam.
Case (a) empty-then-full = genuine RED (payload-blind guard at persist.c:822
no-ops the corrective write, Expected 64 Was 0). Cases (b) full-then-empty
and (c) identical-rewrite = baseline-passing pins that constrain the 2.2
fix asymmetry (empty must never overwrite stored full; identical re-stream
stays idempotent). 7 tests/1 RED/no ASAN.
New test_ha_core_safety.c with deterministic gate/probe seams (no sleeps,
drain-before-fini per bug-1224): payload-controllable WAL writer, on-disk
(term,pcrc,len) readback probe, walcompare observer, apply-gap + kill/
election injection for phases 2.3/4.1/5.1. Smoke-RED (Expected 64 Was 0)
proves the payload-blind (term,lsn)-only guard at persist.c:822 drops a
corrective full-payload write at a committed LSN. 5 tests/1 RED/4 seam
PASS, no ASAN errors.
Per-member (lsn,term,pcrc,present) report + committed-vs-uncommitted
divergence classification via walcompare_report()/--report. Soak signal
(OK/exit-code) preserved. 4 new unit tests, all GREEN.
With the dispatch flags flipped ON in-test, prove the three receiver-side
liveness properties (production defaults stay OFF):
- P1: while a snapshot (and config-push) transfer is parked in flight on the
slow lane, another endpoint's peer-control message is still processed
promptly on the vtask pool (different thread), with the transfer still
parked — the offloaded transfer does not block the drive path.
- P2: a peer-control ack (classified VTASK_LIVENESS) runs promptly even while
the pool is saturated to the LivenessAdmission reservation boundary with
REQ_BLOCK tasks (one more REQ_BLOCK fast-rejects with -E_XCE_NOT_READY,
proving real saturation). Narrowed to the liveness-dispatch-under-saturation
assertion; commit-advance itself is covered by the commit-engine tests.
- P3: while one endpoint's peer-control body is parked (holding a worker + that
ep busy), another endpoint's body runs concurrently on a different worker —
per-endpoint FIFO does not serialize across endpoints.
All deterministic (cond-var gates, bounded polls). Fixed a flaky teardown-race
hang (bug-1224): the tests released a parked vtask body then immediately called
the cancel-based vtaskmgr_fini while the just-released body was still unwinding
(P2's REQ_BLOCK bodies racing blk_lock teardown the worst). Fix adds end-of-body
completion counters polled to the full expected count before fini, so every
pool body has fully returned (worker idle) before the cancel. slowlane_fini is
graceful (join) so the lane side was already safe.
Verified: 5/5 deterministic isolated runs; full controller suite EXIT=0;
ASan-clean. Completes task 3.4 (3.4a UAF fix + 3.4b tests); the production
flag-flip remains deferred to after the 4.1 partition soak + 4.2 regression
sweep.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S6fDCtXkkEgupu7rUah1y2
When the (still-default-OFF) peer-control dispatch flag is ON,
raft_cb_become_follower runs as a vtask pool worker and frees every peer
vote-ep while other pool workers may still hold those eps' data — a UAF
(bug-1197). This makes that path quiescence-safe so the flag can later be
flipped ON (deferred to the 4.x prod-flip gate; production stays OFF here).
Mechanism (no libxce-wide endpoint refcount; reuses the existing per-ep FIFO +
busy serialization):
- Deferred teardown-as-vtask: the loser loop, when dispatch is ON and the pool
is wired, does per vote-ep endpoint_mark_tearing_down -> iomgr_unmonitor ->
enqueue a VTASK_IO/VTASK_LIVENESS teardown vtask bound to that ep. Per-ep busy
FIFO makes it run strictly after any in-flight/queued same-ep peer-control
vtask; the body NULLs iod->ep before endpoint_fini+free(ep) to disarm
run_task's post-body endpoint_unblock_tasks (which would touch the freed
ep->lock). OFF / pool-unwired path is byte-for-byte the legacy endpoint_fini.
- RCU-like drain closes the dispatch/teardown TOCTOU window: new _Atomic int
endpoint_t.dispatch_inflight (+ tearing_down:1 bit). The ON dispatch brackets
its flag-check+enqueue with fetch_add/fetch_sub (seq_cst);
endpoint_mark_tearing_down sets the flag under ep->lock, releases, then spins
until dispatch_inflight drains to 0. So every dispatch that read the flag
false finishes its enqueue before mark returns (FIFO-before the teardown
vtask); any later dispatch reads the flag set and drops the packet. ep->lock
is deliberately NOT held across the enqueue (it inverts with the taskq lock in
vtask_eligible); the counter is the lock-free handshake. Drain is bounded: the
held window is just a calloc + non-blocking enqueue on the single io_worker.
Still open before the production flag flip (4.x): the borrowed-ep race in
snapshot_lane_fn/configpush_lane_fn is distinct (slowlane thread vs io_worker
RDHUP teardown, not the vtask-pool FIFO) and needs its own per-standby-ep
discipline.
Tests: test_ha_vep_teardown.c — 5 ASan tests (ordering, late-event drop, run_task
unblock disarm, OFF-path unchanged, deterministic mark-drains-inflight-dispatch).
xcelib_test 282/0; controller_unit_test EXIT=0; ASan-clean. Adversarial
cpp-review: no CRITICAL/HIGH; handshake formally sound, flag-ON path race-free.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S6fDCtXkkEgupu7rUah1y2
push_config_transport_only spawns one thread per standby then joins them with a
CONF_PUSH_TIMEOUT_MS bounded wait — blocking the caller. On the requester-less
drive-thread paths (promotion + heartbeat convergence) that wait stalls the
io_worker. Route those through ha_config_push_offloadable, gated by
g_drive_async_configpush_offload (default OFF → inline, byte-for-byte legacy;
ON → slow lane, non-blocking).
Flag ON deep-copies the config bytes + sha into a lane ctx (caller keeps owning
and freeing its own buffer); a single cluster-wide single-flight guard
(ha_state_t.configpush_inflight scalar CAS + lane key=1) bounds it to one
config-push fan-out in flight; the in-flight flag is cleared on every terminal
path (two alloc failures, -EEXIST, hard submit error, lane completion). Send
body factored into ha_config_push_do_send.
Three requester-less drive-thread call sites converted: raft_cb_become_leader
(promotion), the HA_REPL_PUSH_CONFIG heartbeat case, and the direct-CTRL_PRIMARY
FSM promotion branch. The admin-upgrade barrier (push_config_to_standbys, has a
waiting requester) and join.c are untouched.
Lands DORMANT like tasks 3.1/3.2: the lane reads c->ha.standby_endpoints and
writes those borrowed standby endpoints, racing io_worker RDHUP teardown if run
off-thread (bug-1197 family). Flag OFF keeps push+teardown serialized on the
io_worker. Task 3.4 flips this ON together with the snapshot and peerctrl flags
after establishing endpoint-lifetime discipline.
Tests (controller suite EXIT=0): test_configpush_offload_runs_on_lane,
test_configpush_inline_when_flag_off, test_configpush_offload_dedups.
Adversarial cpp-review: no CRITICAL/HIGH/MEDIUM findings.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S6fDCtXkkEgupu7rUah1y2
Part B (LIVE, default-ON): trim_wal_segments now bounds WAL-segment deletion
by repl_trim_lsn(&p->repl, active_seg_lsn) = min(active segment LSN, every
active standby acked_lsn, every valid disconnected-slot last_disconnected_lsn),
after repl_expire_disconnect_slots ages out stale slot guards. floor <=
active_seg_lsn structurally, so the guard can only preserve more segments,
never delete one a live standby still needs — closes the bug-795/828
trim-vs-cursor race for connected/recently-disconnected standbys (bug-1147
stopgap; empty/cursor=0 join still needs entity-bearing snapshots).
Part A (DORMANT, g_drive_async_snapshot_offload default OFF): ha_snapshot_send_
dispatch routes HA_REPL_SEND_SNAPSHOT inline (flag OFF — byte-for-byte legacy,
on io_worker) or to slowlane_submit+snapshot_lane_fn (flag ON). Send body
factored into ha_snapshot_do_send. Per-peer single-flight via
ha_state_t.snapshot_inflight[] CAS + slowlane key; in-flight flag cleared on
all four terminal paths, mirroring the reconnect offload (task 2.1).
Lands dormant like task 3.1: snapshot_lane_fn borrows a standby endpoint it
does not own, so flag-ON would race io_worker RDHUP teardown (cross-thread UAF,
bug-1197 family). Flag OFF keeps send+teardown serialized on the io_worker.
Task 3.4 is the single gate that flips both this and the peerctrl flag ON after
establishing endpoint-lifetime discipline; bug-1198 stays open by design until
then. The offload flag was initially authored default-ON (would ship the UAF)
and corrected to OFF in ha.c and the ha.h accessor doc (bug-1210).
Tests (controller 196/0, 0 new leaks): test_snapshot_offload_runs_on_lane,
test_snapshot_inline_when_flag_off, test_snapshot_offload_dedups_per_peer,
test_trim_guard_preserves_standby_segments,
test_trim_without_standbys_proceeds_normally. Adversarial cpp-review: GO.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S6fDCtXkkEgupu7rUah1y2
Lands the PeerCtrlDispatch machinery behind a DEFAULT-OFF flag
(g_drive_async_peerctrl_dispatch_enabled); production behavior is
UNCHANGED. peer_ctrl_msg_handler becomes a thin shim that takes
ownership of ep->fsm_in.pkt and either runs the routing body inline
(flag OFF, byte-for-byte the prior path) or dispatches it to the vtask
pool via vtask_enq_classified (flag ON). The 3 routers now take pkt as
an explicit param (no cross-thread ep->fsm_in.pkt re-read). Per-endpoint
arrival order is enforced by bind_vtask's endpoint_block_tasks.
Packet ownership: shim clears ep->fsm_in.pkt at dispatch (sole-owner
transfer); peer_ctrl_vtask_entry NULLs iod->pkt before the body frees
it once. New vtask_t.owns_io_pkt (default 0) lets taskq_item_killer free
the carried packet for an un-executed queued task at vtaskmgr_fini WITHOUT
double-freeing the libxce endpoint-owned path (bug-1199).
Adversarial review found two FLAG-ON hazards, documented with loud
comments (flag is OFF so production is unaffected), to be resolved before
task 3.4 flips the flag ON:
- bug-1197 (CRITICAL): raft_cb_become_follower endpoint_fini()s peer
vote-eps from a pool worker, racing the io_worker's read of ep->data;
needs iomgr_unmonitor before endpoint_fini in every pool-reachable
teardown.
- bug-1198 (HIGH): peer_ctrl_classify tags all work VTASK_LIVENESS, but
the CTRL_PRIMARY repl-ack path can run a blocking snapshot checkpoint
inline; resolved by task 3.2 (offload snapshot to SlowLane).
Per spec, 3.1 is not 'done' until the task 3.4 deadlock gate is green.
Tests: 3 new peerctrl tests; controller 196/196, lib 282/0; 0 net leaks.
Escalates the single-tick unit tests (15-17) to sustained liveness: with
one peer unreachable (reconnect parked in-flight on the lane for the whole
window), drives 3 consecutive heartbeat ticks against a 4-node cluster
(two survivors) and asserts every survivor keeps receiving heartbeats on
every tick (g_nop_calls == 2*3), each tick returns promptly (delaymgr
never stalled), the reconnect stays in-flight throughout, and is deduped
across all ticks (connect hook submitted exactly once — Req 2.5).
RED arm (offload flag OFF) proves the inline connect blocks the first
tick, so survivors stop getting heartbeats (g_nop_calls < 6). The flag
toggle is the RED<->GREEN switch; production is unchanged (test-only task).
test_ha_liveness suite 23 -> 25 tests; full controller suite 196/196 pass.
When a reconnect registers a new outbound control channel for peer X,
on_standby_connected now evicts any pre-existing standby_endpoints entry
for the same peer_idx (a promoted vote-ep or a stale prior channel),
keeping exactly one live outbound channel per peer (Req 2.6/4.4). The
stale ep is torn down OUTSIDE ha->lock via standby_ep_err_handler_primary
(which re-takes the lock) and reclaimed; resolution is strictly per-peer.
Also fixes endpoint leaks on the endpoint_get() calloc paths: every
endpoint_fini() error path now free(ep) (fini reclaims inner members
only), closing the task-2.1 GREEN-test leak masked by detect_leaks=0.
Tests 18-19 in test_ha_liveness.c assert single-survivor resolution and
per-peer isolation. 196/196 controller unit tests pass.
Heartbeat timer detects a disconnected peer, CAS-acquires a per-peer
single-flight flag, slowlane_submits the bounded connect, and returns — the
delaymgr never blocks on connect. Lane worker (reconnect_lane_fn) does the
bounded endpoint_connect + lock-guarded iomgr_monitor; flag cleared on all
terminal paths (incl. -EEXIST race fix). Default-ON kill-switch retains the
inline path for TDD-RED/fallback. Never self-terminates on failure. 2.2 adds
the inbound/outbound race + failure hardening (documented seam). 196/0 green.
vtaskmgr gains vtask_class_t (LIVENESS/LIVE_BLOCK/REQ_BLOCK) + a pool-level
blocking reservation: REQ_BLOCK fast-rejects -XCE_ERR_NOT_READY past
n_vcpus-R; LIVENESS never gated (deadlock-freedom). commit_submit folds its
inflight_waits onto the pool via commit_set_pool; production wired in
cluster.c phase2 (vtaskmgr_set_liveness_reserved(R) + commit_set_pool).
Lock order p->lock->ce->lock->blk_lock. Dormant until 3.1. Commit suites
38/30/22/38 green; lib 282/0, controller 196/0, ASAN clean. Phase 1 done.
Dedicated-pthread pool isolated from the vtask pool; non-blocking slowlane_submit
(0 enqueued / -EEXIST deduped / -EAGAIN cap-full-deferred), admission cap on
running tasks, per-key in-flight dedup, run-exactly-once, drain+join fini. Wired
into controller lifecycle (dormant; consumers land in 2.x/3.x). 7 unit tests,
mutation-verified cap+dedup; full suite 194/0 green, 15x ASAN.
drive_async_liveness_reserved = max(1, min(n_peers-1, n_vcpus-1)) — single
source of truth for VTASK_LIVENESS_RESERVED (deadlock-freedom floor applied
last). New DEFAULT_CONNECT_TIMEOUT_MS / DEFAULT_SLOWLANE_* constants. Resolved
reservation logged at init; under-provisioned (n_vcpus<n_peers) clamp WARNs
loudly, never self-terminates. 8 unit cases, mutation-verified.
test_demotion_replay_yields_committed_only flaked (~16% on overlayfs, but
fs-independently too). Two root causes, both test-harness artifacts (NOT product
bugs; production self-restart is execv on a real fs and never overlaps persist
contexts or runs an auto-committer during demotion):
1. single-node commit race: the fixture's live commit engine on_durable_advance
auto-commits on n_peers=1, advancing committed_lsn past the test's boundary so
the 'uncommitted' suffix became committed. Fix: detach on_durable_advance +
re-pin committed_lsn to the test's own committed_boundary, so the suffix stays
genuinely uncommitted (the test's premise).
2. overlayfs fd-incoherence: a fresh persist_t recovering over the same files
reads a stale post-ftruncate size on overlayfs. Fix: hybrid statfs gate —
real fs keeps the full fresh boot-recovery assertion; overlayfs asserts the
same property via the coherent live-context current_lsn.
Test-only; production truncate (ftruncate+fdatasync) untouched. 0/25 runs fail
(was 4/25 with the prior persist_stop-only attempt).
The bug-850/851 forward-gap contiguity guard (persist.c:839, added in 20e59d0b)
correctly rejects a catch-up entry whose lsn is ahead of the WAL tail (-EAGAIN).
7 test_wal_catchup_* tests in test_config_repl.c predate the guard and applied
non-contiguous LSNs (42, 10-12, 1000+) to a fresh persist (current_lsn=1),
failing deterministically. Seed current_lsn to each test's first applied LSN so
the in-order stream is contiguous (mirroring the real catch-up streamer); the
apply->advance path and all asserted semantics are unchanged. Test-only; the
production contiguity guard is untouched. 179 controller tests, 0 failures (x3).
Adds two controller-level regression tests driving the production raft_on_vote_reply
via ha->raft (test_ha_election.c): a duplicated vote-grant from one peer must not
double-count toward quorum (bug-1095) and a stale-term reply must be dropped
(bug-1096) — both asserted on role/promotion (no two leaders per term). Formally
absorbs bug-1095/1096 into the ha-term-safety spec (Implementation Note) mapping to
its Requirement 1 / Objective; the raft.c fix (b5b7e01) is owned there with
protocol-suite regression at both the libxce (test_vote_reply_*) and controller
(test_ha_election) levels. No production source changed.
The post-failover wait-primary/expect-job probes used the full masters list led
by the just-killed node, triggering libxce bug-854 (positional discovery can't
fail over from a dead-first master). Now they use a live-first list excluding the
killed primary.
NOTE: this exposes a deeper, separate post-failover AVAILABILITY issue (not data
loss): the new primary stays stuck in a catch-up loop with a lagging standby
(standby[0] lsn=5 < committed_lsn=6) and does not serve clients, so wait-primary
still times out. That is a catch-up/serving-readiness liveness concern orthogonal
to bug-828's committed-job DATA SAFETY, which is fixed and verified (walcompare
committed-prefix identical, jobs preserved on disk).
ROOT CAUSE (confirmed via live instrumentation — NOT a durability violation):
ha_enter_real_election truncated the WAL to last_known_committed_lsn BEFORE the
vote. That watermark lags the true commit point (the primary committed LSN 2-5 on
a durable majority then died before a heartbeat carried committed=5 to the
standby), so the cutoff was 1; persist_truncate_wal_above -> clamp_durable_lsn
lowered the standby's durable_lsn 5->1, physically destroying durably-committed
entries before the election even computed the safe point. The candidate then
advertised floor=1, safe_committed_lsn=1, and the post-election truncate kept only
LSN 1. This directly violated the documented rule: 'Never use last_known_committed
_lsn for truncation — it may be stale.'
FIX: delete the premature truncate. The candidate keeps its full durable log; the
ONLY truncates are now the authoritative votes-derived post-election
persist_truncate_wal_above(safe_committed_lsn) (raft_cb_become_leader) + the
library on_truncate_from (term,lsn) reconcile — both before any commit under the
new leader.
SAFE (reviewer-verified): a divergent uncommitted tail can only exist at a
stale/lower term (single-writer); the library's term-primary (lastLogTerm,
lastLogIndex) freshness gate denies such a candidate — correct now that task 3.4
fixed the term axis (the prerequisite). No divergent entry can win-and-commit; no
bug-339 election-loop. 177 unit tests + a RED-proven regression test.
LIVE: clean failover now preserves committed jobs — walcompare committed-prefix
identical across all 3 members, both jobs present on disk, across multiple runs.
(Residual harness EXIT 1 is the SEPARATE pre-existing libxce client bug-854:
client can't reach the live primary when the dead node is first in the masters
list — a client-discovery defect, orthogonal to server-side data safety.)
