Non-blocking election initiator that returns immediately after registering
vote endpoints with iomgr and scheduling the election timeout watchdog.
- Single-node shortcircuit (n_peers==1): allocates self-only ha_elect_ctx_t,
calls ha_elect_evaluate_and_signal directly, frees ctx inline — no iomgr
or delaymgr involvement; returns in < 1ms
- Multi-node: allocates ha_elect_ctx_t, per-peer vote_ep_ctx_t, calls
endpoint_connect + iomgr_monitor for each peer; schedules election timeout
via delay_task_ms; skips peer on connect failure (counted as denied)
- election_timeout_fn: delaymgr callback that fires ha_elect_evaluate_and_signal
after election_timeout_ms, unless cancelled flag is set (lock-free cancellation)
- vote_ep_err_handler: counts unreachable peers as denied votes
- Declares ha_start_election_async in ha.h with full doc comment
- 5 Unity tests in test_ha_start_election_async.c: returns < 5ms, stores
n_peers, shortcircuit fires immediately, n_peers stored for multi-peer,
term incremented — all GREEN with ASAN enabled
Replace stub with full iomgr-native vote reply decoder:
- Reads RequestVoteReply fields into local scalars BEFORE capn_free (UAF fix)
- Term fencing: atomic update ha->term if peer term > ours
- Error path: decode failure counts peer as denied vote
- Test seam: xce_vote_reply_hook for unit testing without real packets
- 4 new ASAN-clean unit tests: field decode, denied vote, term fencing, no-UAF
The pre-existing vote_request_thread UAF in the old pthread path remains
but is targeted for removal in task 5.3 (old code removal).
- vote_ep_ctx_t: per-peer context (ha, c, ctx, peer_idx, term/tag/lsn/name)
- election_timeout_ctx_t: cancelled flag + context for delay watchdog
- on_vote_connected(): iomgr callback fires after SSL handshake; builds
xce_request_t{opcode=OPCode_requestVote}, calls xce_request, sets msg_handler
- vote_reply_msg_handler stub (returns 0; implemented in task 2.3)
- Test seam: xce_vote_request_hook for unit testing without live SSL
- 4 new unit tests: opcode, field encoding, msg_handler set, cancelled flag
Context note: vctx->c is NULL in test helper — task 2.3 must use real cluster_t*
Task 2.1 of election-iomgr-refactor spec. Adds the new ha_state_t fields
required for the COMMITTING phase FSM, the CTRL_PRIMARY_COMMITTING role enum
value, and the committing_timeout_ms config field with its default constant.
ha_init() explicitly zero-initialises all new fields. Unit test verifies
zero-init and enum distinctness.
Requirements: 5.2, 8.1 (election-iomgr-refactor spec)
Two Raft correctness fixes:
1. Priority staggering in ha_wait_for_heartbeat_or_timeout():
Add my_priority × election_priority_step_ms to the timeout so
ctrl-a (priority=0) times out first and starts election before
ctrl-b (priority=1) and ctrl-c (priority=2). This gives the
highest-priority node a head start and prevents simultaneous
campaigning that causes perpetual split votes.
2. candidate_id in vote RPC:
Pass the actual node name (myconf->name) as candidate_id instead
of "". This fixes the voted_for deduplication gate (Req 2.6):
a peer that already voted for ctrl-a will correctly deny a
second vote request from ctrl-b in the same term.
Thread context gets my_name field; am_i_primary_quorum() takes
my_name parameter; all call sites updated (myapp.c, ha.c RDHUP,
test_ha_election.c stubs).
- Probe all peers: any tag>0 -> defer_config_fetch=true; all-zero -> proceed;
none reachable -> exponential backoff 500ms->10s cap with WARN per attempt
- Wire into myapp.c: before ha_wait_for_heartbeat_or_timeout()
- Post-election: defer_config_fetch && CTRL_STANDBY -> fetch_config_from_primary()
- INFO log for all three bootstrap outcomes (Req 10.2)
- XCE_TESTING hook for probe mock; test_ha_bootstrap_support.c installs mock
- 9/9 bootstrap tests GREEN, 141/141 full suite GREEN
- sem_timedwait on heartbeat_seen semaphore with CLOCK_REALTIME deadline
- deadline = now + election_timeout_ms + xorshift64 jitter
- Returns CTRL_STANDBY on heartbeat arrival (calls ha_do_demote)
- Returns CTRL_ELECTING on timeout (caller drives election)
- Allows OPCode_heartbeat through dispatch gate in CTRL_INIT state
- 3 new unit tests: standby-on-heartbeat, electing-on-timeout, gate-allows-heartbeat
- 24 Tests 0 Failures in test_ha_startup suite
RED-phase tests for 4 startup validation functions — all fail at link time
because the functions under test do not exist yet:
- validate_peer_count: even N>1 returns -EINVAL, odd N returns 0
- validate_cert_files: missing cert/key returns -ENOENT with full path
in err_buf output param (asserted via strstr)
- validate_vcpus: vcpus<=0 returns -EINVAL, positive returns 0
- validate_startup_config: vcpus key in config returns 0 (not fatal)
and writes deprecation text into warn_buf (asserted via strstr)
xce_replconfig_reply_raw() - primary sends reply with real bytes via endpoint
xce_replconfig_req_ssl() - standby sends request over raw SSL socket
xce_replconfig_reply_ssl_decode() - standby decodes reply from raw SSL
xce_upgrade_config_req_extract() - documents architectural limitation; returns -ENOTSUP
xce_upgrade_config_req_extract_raw() - extract bytes from raw packet for OP_upgradeConfig
Same bypass pattern as existing xce_replconfigpush_req_raw(): build the
capnp message directly via capn_new_list8 + capn_setv8, sidestepping the
encode_Data_ptr path that routes raw bytes through xce_data_t (a
discriminated cluster-data union that cannot carry raw byte arrays).
Unblocks handle_config_request() and do_one_config_fetch() wiring.
Task A research finding: xce_upgrade_config_req_extract(xce_request_t*)
is unimplementable because xce_decode() calls capn_free() before any
handler runs, and decode_Data_ptr converts the wire-format List(UInt8)
into a zero-filled xce_data_t. Task D must capture the raw io_packet_t
bytes before xce_decode tears them down, then call the _raw variant.
Replaces blocking pthread_join() per thread with a CLOCK_MONOTONIC
deadline + 5ms poll loop. CONF_PUSH_TIMEOUT_MS (500ms) now enforced.
Matches design §6.3 aggregate timeout guarantee.
- Add done field to push_ctx_t; push_thread sets it on exit
- Add static wait_all_with_timeout() before push_config_to_standbys()
- Wire push_config_to_standbys() to use wait_all_with_timeout()
- Add #include <stdatomic.h> to config_repl.c
- Guard push_ctx_t local typedef with #ifndef XCE_TESTING
- Expose push_ctx_t and wait_all_with_timeout_for_test() in header
under XCE_TESTING for unit test access
- Add test_wait_all_with_timeout_slow_threads (timeout fires, acked=0)
- Add test_wait_all_with_timeout_fast_threads (all complete, acked=3)
- Update design doc §6.3 with actual implementation signature and
5ms poll interval note
load_primary_config() reads from workdir/name/conf — conf_save_config()
was writing to workdir/conf. Latent bug: would have corrupted upgrade
restart cycle once Task 11 wired the upgrade path.
Update all conf_read_current_filename, conf_get_saved_tag, and
conf_check_stale calls in the test suite to use the corrected
effective_dir (workdir/name) path structure. Add new test
test_conf_save_config_path_consistency that explicitly verifies the
written path matches what load_primary_config() reads.
Root cause: test_heartbeat_stale_no_crash_without_primary had
heartbeat_timeout_ms=100 < heartbeat_interval_ms=3000, causing ha_init
to return -EINVAL before memset. The test ignored the return value and
called ha_fini on garbage stack memory. The watchdog_thread field
happened to hold the value 3 (from a prior stack frame), so
ha_stop_watchdog called pthread_join(3, NULL) — crash at 0x2d3
(__pthread_clockjoin_ex accessing thread-struct field at offset 0x2d0).
Fix 1 (test): valid config (interval=2000, timeout=3000). Staleness is
injected via last_heartbeat -= 10s, so timeout value was irrelevant.
Added TEST_ASSERT_EQUAL_INT check on ha_init return.
Fix 2 (ha_init): move memset before validation so ha_fini is safe to
call even after a failed init — prevents the same bug class in callers
that check ha_init's return late.
Verified: test_ha_role 11/11 PASS in both non-ASAN and ASAN builds.
- load_primary_config(): resolves conf/current, reads raw bytes, computes
SHA-256 tag, decodes Cap'n Proto via load_cluster_config_from_file(),
checks reserved names, sets config_generation, checks staleness
- myconf_fini(): frees conffile and cluster_config (calls free_ClusterConfig)
- Remove static cf global from myconf.c; get_default_conf() now uses a
local struct cluster_configuration* via load_cluster_config()
- Add load_primary_config_for_test() under XCE_TESTING in config_repl.c
to test path resolution without triggering FATAL
- Add xce/cluster_def.h include to config_repl.c and test_config_repl.c
so cluster_t is complete when XCE_TESTING is active
- TDD: test_load_primary_config_missing_returns_error passes (18/18)
WAL payloads:
- Job state transitions (START/FINISH/FAIL/STOP/RESUME/UPDATE etc):
wal_jobstate_t {uint64_t jobid, uint32_t state} — restores exact state flags
- Queue state (QUEUE_CTRL): wal_queuehdr_t {uint32_t status} + name string —
re-applies admin open/close/active/inactive after config queues are built
- Worker CTRL: existing [uint32_t detail][capnp xce_worker_t] unchanged
New recovery functions:
- restore_job_state(c, jobid, state): looks up job, overwrites state flags
- restore_queue_state(c, name, status): looks up queue, overwrites status
apply_wal_entry: dispatches all WAL types including job state and queue
test_repl_apply.c: weak stubs for restore_job_state/restore_queue_state
so unit test binary links without job.c/queue.c
Add test-only function ha_trigger_manual_failover_for_test() to exercise manual
failover state machine (demote → promote cycle) without requiring live cluster_t.
Test coverage:
- test_manual_failover_transitions_role_and_increments_term: Validates role
transitions (PRIMARY → STANDBY → PRIMARY) and term monotonicity
- test_manual_failover_resets_hooks_registered: Confirms demotion resets the
hooks_registered idempotency guard
- test_manual_failover_monotonic_term_across_multiple_cycles: Validates term
remains monotonically increasing across 5 consecutive failover cycles
Implementation:
- Exposed only under #ifdef XCE_TESTING in ha.h
- Function body (6 lines): calls ha_do_demote() then ha_do_promote(); returns
the new term value via atomic_load_explicit()
- Enables design validation (P3-6) without test-cluster infrastructure
All tests pass. Build clean.
Add test_p2_integration.c with 7 integration tests covering the assembled P2
replication system: WAL_CHECKPOINT assert invariant, trim_lsn with active standby,
checkpoint must not update last_replicated_crc, sync degraded mode, full catch-up
lifecycle, needs_snapshot boundary conditions, and API completeness gate.
All 32 controller unit tests pass (0 failures).
Implement the catch-up state machine as testable pure-logic functions:
- repl_start_catchup(): marks standby in_catch_up=1, stores join_applied_lsn
- repl_complete_catchup(): clears in_catch_up=0, broadcasts ack_cond so any
blocked repl_wait_ack() re-checks the ACK condition immediately
- repl_needs_snapshot(): pure predicate — returns 1 when standby LSN predates
oldest surviving WAL segment (snapshot transfer required), 0 otherwise
Also fixes pre-existing linker error: repl.c was missing from controller_src
(xce_controller production binary), causing undefined references to repl_*
symbols introduced in P2-4.
7 new TDD tests in test_repl_catchup.c — all pass. Existing tests green.
- Move repl.h from controller/ to include/ (shared header) to break
persist.h ↔ repl.h circular include
- Extract wal_entry_hdr_t + wal_entry_type into include/wal_types.h so
repl.h can include only what it needs without pulling in all of persist.h
- Add replicator_t repl field to persist_t (embedded by value, P2-4)
- Wire repl_init/repl_fini into persist_init/persist_fini lifecycle
- Wire repl_broadcast into persist_wal_async after each WAL write;
last_replicated_crc updated here (not in persist_write_checkpoint_marker)
- Wire repl_wait_ack into persist_wal_sync_append; returns 0 on local
WAL success; sync_rc_out carries -ENODEV/-ETIMEDOUT for degraded mode
- Add 4 TDD tests in test_persist_repl.c: structural repl field check,
async no-standbys succeeds, sync degraded mode rc, checkpoint CRC invariant
Implements sync replication wait: primary blocks until at least one non-catching-up
standby ACKs the target LSN, or times out. Uses pthread_cond_timedwait with
CLOCK_REALTIME deadline. Inner loop rechecks all standbys after each wakeup to
guard against spurious wakeups.
ACK deadlock prevention: repl_on_ack() is called exclusively from the io_worker
read callback (not vtaskmgr), so it only does atomic_store + pthread_cond_signal —
safe to call while vcpu threads block in repl_wait_ack().
4 new TDD tests (all green, 9 total in test_repl_unit):
- test_wait_ack_no_standbys_returns_enodev
- test_wait_ack_already_acked
- test_wait_ack_timeout (verifies >=80ms elapsed)
- test_wait_ack_woken_by_background_ack (pthread thread signals after 30ms)
Upgrade apply_wal_entry() from P0 static no-op stub to the real public
standby replay path:
- Reject oversized payloads (> MAX_WAL_PAYLOAD_BYTES) with -EMSGSIZE
- Skip WAL_CHECKPOINT (100) entries silently — local-only markers, never
replicated to standbys; current_lsn is NOT advanced on skip
- Skip unknown types (> WAL_ENTRY_TYPE_MAX) with WARN log and rc=0 for
forward compatibility with WAL written by newer controller versions
- Advance current_lsn to hdr->lsn+1 and update last_crc under p->lock
for all accepted known entries
- Gate restore_job()/worker_from_capnp() calls on p->cluster != NULL so
unit tests work without a full cluster wired in
- Add NULL guard returning -EINVAL for missing p or hdr
Add public declaration in persist.h with forward-declare stubs for
restore_job/worker_from_capnp in persist.c (avoids heavy cluster.h chain).
Test suite: 5 new Unity tests in test_repl_apply.c covering all branches.
Weak stubs for restore_job/worker_from_capnp in the test file satisfy the
linker without linking job.c/worker.c's heavy dependency graph.
All 5 new tests pass; full controller suite green.
Add replicator_t structure with per-standby connection slots (standby_conn_t),
lifecycle (repl_init/repl_fini), slot management (repl_add_standby,
repl_remove_standby, repl_expire_disconnect_slots), ACK tracking
(repl_on_ack), WAL trim guard (repl_trim_lsn), and stubs for
repl_broadcast/repl_wait_ack (wired in P2-3/P2-4).
Uses mylock_t (pthread_mutex_t alias) with mylock_lock/mylock_unlock.
snap_interval_s==0 in repl_expire_disconnect_slots forces immediate expiry
to support deterministic unit testing.
5 new Unity tests all pass; 115 pre-existing controller tests unchanged.
Add redirect helpers to ha.c/ha.h so a standby controller never accepts
join requests as if it were the primary:
- ha_should_redirect(): returns 1 when role is STANDBY and primary_host/port
are known — caller should send E_XCE_REDIRECT.
- ha_no_primary_known(): returns 1 when role is STANDBY but primary address
is not yet known — caller should send E_XCE_NOMASTER (retry later).
- Add E_XCE_NOMASTER and E_XCE_REDIRECT to errnox.h.
- Wire both guards into handle_join_() in join.c (before the role switch)
so all join types (worker, scheduler, apiserver, client) are protected.
- Full redirect response sends status=-E_XCE_REDIRECT with nodata body;
the primary host:port are logged so operators can trace misrouted clients.
Full Cap'n Proto RedirectInfo response body is deferred to a follow-up
(schema union would require regenerating capnp bindings).
5 new TDD tests — 110 total, 0 failures.
