Each ten-second queue heartbeat mints a fresh idempotency key and
permanently inserts a row. Published outbox rows and expired/revoked
sessions were never purged either -- the maintenance role performed
lifecycle reconciliation only. At 10,000 queued players heartbeats alone
add roughly 60,000 durable rows per minute, so table and index growth,
vacuum pressure, backup size and recovery time were all unbounded on a
service intended to scale horizontally.
Add retention windows chosen to exceed every retry and recovery horizon
that could still consult the row -- deleting an idempotency key early
would turn a client replay into a second real mutation, so this is a
correctness bound, not just a housekeeping one. Dead-lettered outbox
rows are kept longest, being the record of events never delivered.
Deletes run in bounded SKIP LOCKED batches so a purge never blocks live
traffic, never holds a long transaction, and concurrent maintenance
replicas do not contend. Indexes back each predicate so a pass cannot
degrade into a sequential scan of the table it is bounding. The
maintenance role reports rows purged, the backlog past its window
(deletion lag), and any dead-lettered events.
Also make the migration-rollback test derive its step counts instead of
hardcoding them: adding a migration silently shifted the fixed counts so
the failure surfaced as an unrelated "0006 rollback did not drop
matches.allocation_id".
The Deployment runs two replicas, but WebSocket subscribers live only in
each process's in-memory hub. Every replica races to read the same
global unpublished outbox rows, and publishing succeeded even when the
winning replica held no matching local subscriber -- that replica then
set the single global published_at. A client connected to the other
replica never received the event, and delivery degraded further with
each replica added. REST recovery eventually converged, but short-lived
proposal transitions could be observed late or not at all.
Publish committed events through PostgreSQL LISTEN/NOTIFY so the replica
that owns the subscriber's connection delivers it, regardless of which
replica drained the row. The listener holds its own pgx connection --
LISTEN is session state, so a pooled database/sql connection cannot
carry it -- and reconnects with backoff, since losing it would silently
downgrade that replica's subscribers to REST-only recovery.
The fan-out is optional: without EventFanout configured, behaviour is
unchanged local-hub publication, which stays correct for a single
replica and for tests. Only outbox-sourced events are routed through it;
the in-request-path publishes remain local, as those are a latency
optimisation for the caller's own connection.
Fan-out needs a wire shape of its own because ControlPlaneEvent hides
PlayerID from clients, and the recipient is exactly what a peer replica
needs to route on.
banned_until and ban_reason have been in the schema since 0001, but no
production query ever read them -- grepping the tree found no reference
outside the migration itself. The only ban check was an in-memory map on
domain.TicketVerifier used by domain tests. Once real Steam login is
wired, a banned identity would keep full access through every existing
session until expiry and could obtain new ones.
Make the ban part of the durable authentication transaction rather than
a policy each login adapter must remember to re-implement:
- Session issuance inserts only when the identity exists and has no
active ban, so a banned player cannot mint a session.
- Authentication joins the identity and rejects an active ban on every
request, so a ban takes effect immediately on every replica rather
than at session expiry.
- ApplyIdentityBan sets the ban and revokes that identity's sessions in
one serializable transaction, closing the window where the ban is
durable but another replica still accepts an issued session.
Bans are time-bounded and clearing one does not resurrect sessions the
ban revoked.
Tests cover enforcement across two independently constructed stores
standing in for two replicas, expiry/unban semantics, and -- separately,
because revocation would otherwise mask it -- that a ban applied without
revoking anything still blocks the next request.
The candidate projection selected only from queue_tickets and its scan
never set Candidate.Rating, so every PostgreSQL-sourced ranked candidate
arrived with Go's zero value. Rating tolerance, selection scoring and
team partitioning all read that field, so ranked matchmaking treated a
900-rated player as identical to a 2100-rated one. Unit tests missed it
because they construct candidates with ratings already populated.
Join the ratings table, defaulting to domain.GlickoInitialRating for a
player with no ratings row yet -- a genuinely new profile, matching the
column default.
Fix the same defect on the Redis path too, which is reached differently:
the projection is seeded from the candidate CreateQueueTicket builds,
not from the candidate query, and that candidate also left Rating unset.
Resolve the rating inside the enqueue transaction so both projections
agree on one authoritative value. The rating is never client-supplied.
Add a store-backed test with deliberately distant ratings (900 vs 2100)
plus an unrated player, asserting both projections and that the spread
survives. Verified it fails without the fix.
ApplyInitialConnectPlan wrote a payload of {match_id,state,action},
omitting event, revision, resource_id, occurred_at and player_ids --
every field deliverStateOutboxEvent requires. Delivery rejected the row,
dispatch returned on the first error so it was never acknowledged, and
because reads are ordered oldest-first it was retried ahead of every
later state_changed event on every 100ms poll. One initial-connect
transition therefore blocked lifecycle delivery for all matches, not
just its own.
Two independent fixes, since either alone leaves the system fragile:
Build envelopes through one validating helper (MarshalOutboxEnvelope)
and convert all five writers to it. A writer that omits a required
field now fails its own transaction instead of committing a row that
can only ever poison the queue. The helper takes revision as int64 so
the -1 "nothing matched" sentinel some CTEs return surfaces as an error
rather than wrapping to a huge uint64.
Make dispatch resilient regardless: a delivery failure is now counted
against that row and the batch continues, with the row dead-lettered
after MaxOutboxDeliveryAttempts so a poison event degrades to one lost
notification instead of a stalled queue. Ordering within an aggregate
is still honoured -- later events of a failed match are deferred, so no
client observes that match's newer state before its older state. An ack
failure still stops the batch, being a database rather than a payload
problem.
Initial-connect events now address every participant, not just the
connected ones: a no-show needs to learn their ticket was failed and a
penalty applied.
Closes the 'concurrent proposal-recovery expiry races' gap noted in
§8.46. GetProposal (read-side recovery) and RespondToProposal both
run the identical expiry-advance SQL in their own transaction, so any
number of them can observe the same past-expiry proposal at once —
this had never been exercised concurrently, only sequentially (the
existing late-response test drives one call at a time).
TestPostgreSQLConcurrentProposalExpiryRecoveryAppliesCooldownsExactlyOnce
races 8 concurrent GetProposal/RespondToProposal calls, each with a
distinct 'now' past the proposal window, against one proposal and
asserts: EXPIRED lands on the proposal and both tickets exactly once,
a PROPOSAL_TIMEOUT penalty lands exactly once per offending player
(not once per racing transaction), and no idempotency row survives a
closed-proposal response. The design already defends against this —
ProposalParticipantExpireSQL only ever flips a still-PENDING row
once, so a losing racer's 'now' can't match
recordProposalTimeoutCooldowns' responded_at filter — this test is
what actually proves that holds under real concurrent load rather
than by inspection.
Verified: real postgres:17-alpine container, go test -tags
integration ./store/... -run
TestPostgreSQLConcurrentProposalExpiryRecoveryAppliesCooldownsExactlyOnce
-race -count=3 clean; full -tags integration ./store/... -race run
clean; full non-integration go build/vet/test -race clean across
every server package; container removed after the run.
The last two commits fixed the severe stranding bug in decline and
timeout, but left a real responsiveness gap: cancelling a ticket
directly while it's part of an OPEN proposal used to leave the OTHER
participant waiting out the full response window for something the
system already knew couldn't happen -- their proposal partner just
abandoned the queue. ProposalExpireRequeueSQL eventually rescues them,
but only after the full window elapses, not immediately.
CascadeCancelToOpenProposal runs inside the same transaction as the
cancel itself: if the cancelled ticket belonged to a currently-OPEN
proposal, decline that proposal right now and requeue every other
participant immediately via the same ProposalDeclineRequeueSQL the
decline path already uses. The cancelling player's own ticket
correctly stays CANCELLED, not swept back into the requeue meant for
everyone else (ProposalDeclineRequeueSQL only touches tickets still at
PROPOSED).
Covered by a real PostgreSQL integration test: cancelling one
participant's ticket mid-proposal immediately declines the proposal
and requeues the other participant with a refreshed expiry, while the
cancelling player's own ticket stays CANCELLED. First draft used a
stale expected revision (0) for the cancel call -- CreateProposal's
own QueueTicketProposeSQL already bumps a ticket's revision to 1 when
forming the proposal, caught immediately by actually running the test
against real Postgres rather than assuming. Clean across 5 runs after
the fix, plus the full integration and unit suites.
The timeout sibling of the previous commit's decline fix: a proposal
that simply times out (the 10s window elapses with no unanimous
response) hits ProposalExpireSQL/ProposalParticipantExpireSQL, and
neither of those -- same as the decline path -- ever touched
queue_tickets. Same severe consequence: every participant still
holding a PROPOSED ticket, response pending or already accepted, is
left stranded (invisible to the matcher, blocking a fresh
queue_create, renewable forever by heartbeat) with no automatic way
back into matchmaking. This path is reached from both GetProposal
(the recovery/read boundary -- a client that missed the expiry event
entirely) and RespondToProposal (a response arriving after the
window), so both needed the fix.
ProposalExpireRequeueSQL mirrors ProposalDeclineRequeueSQL, guarded on
state = 'EXPIRED' so it's safe to call unconditionally right after
ProposalExpireSQL: a no-op on a proposal that's still OPEN, and a
no-op on a proposal that was already EXPIRED on a prior pass (nothing
left at PROPOSED to requeue a second time).
Covered by a real PostgreSQL integration test via GetProposal (nobody
ever responds; recovering the proposal well after its window expires
it and must requeue both participants), confirming both tickets land
back at QUEUED with a refreshed expiry and are visible again to
ListQueuedCandidates. Clean across 5 runs, plus the full integration
and unit suites.
Found by reading the code, not a failing test: no path anywhere
transitioned a queue ticket from PROPOSED back to QUEUED after a
proposal was declined. A stranded PROPOSED ticket is invisible to the
matcher (ListQueuedCandidates only ever reads state='QUEUED'), still
counts as that player's one active ticket (blocking a fresh
queue_create), and is renewable forever by an ordinary heartbeat --
a player proposed a match with someone who then declines had no way
back into matchmaking without realising, on their own, that they
needed to manually cancel first. This affects every participant, not
just the decliner: an uninvolved player who never even responded was
left stuck by someone else's decision.
ProposalDeclineRequeueSQL requeues every participant's ticket,
including the decliner's own -- nothing yet enforces the decline
cooldown task 8.17 documents as a separate, not-yet-built feature, so
leaving anyone behind at PROPOSED today isn't "cooldown behaviour",
it's just broken. Once that cooldown exists it can exempt the
decliner from this immediate requeue; today nothing does.
Covered by a real PostgreSQL integration test: after one player
declines, both the decliner's and an uninvolved participant's tickets
land back at QUEUED with a refreshed expiry, and -- the actual
end-to-end regression -- both are visible again to
ListQueuedCandidates, the same query the matcher itself uses. Clean
across 5 runs, plus the full integration and unit suites.
Closes the last named item on task 8.28 (Health-reclaim): nothing
currently detects or cleans up a match stuck in
ALLOCATING/PROCESS_READY/ASSIGNMENT_READY forever because its server
crashed or was reclaimed by Agones as unhealthy before ever
registering -- players would wait indefinitely for a match that was
never coming.
The design question this was blocked on -- does an abandoned match
auto-requeue its players, or fail and make them re-queue -- isn't
actually open: task 8.50's own stated acceptance criterion already
answers it ("infrastructure-caused cases cannot penalise affected
players"). A server-side crash/reclaim is exactly that, not player
behaviour, so store.ExpireStalledAllocations fails the match but
requeues every participant's ticket to QUEUED with a fresh expiry
(matching the ordinary 30s queue window), releases their
match_participants row (participation_active = false, so they're
matchable again immediately), all inside one FOR UPDATE SKIP LOCKED
pass so a second maintenance replica continues past whatever a
concurrent one is already reclaiming.
Wired into cmd/maintenance alongside the existing season-rollover
sweep: --stalled-allocation-deadline (default 2m) and
--stalled-allocation-batch (default 100).
Covered by a SQL-fragment test and a real PostgreSQL integration test:
two matches (one genuinely stalled, one recent), confirming the
deadline boundary is respected (recent match untouched), both
stranded participants' tickets requeue with a refreshed expiry, the
match_participants row releases, and a second pass doesn't reprocess
an already-FAILED match. Verified clean across 5 runs, plus the full
integration and unit suites.
Races 5 concurrent HeartbeatQueueTicket calls, all at the same expected
revision, against a real PostgreSQL instance -- a genuinely plausible
client scenario (slow-response retry, duplicate tab/process), and one
the existing sequential stale-revision test can't exercise since it
only calls the second heartbeat after the first has already
committed. Asserts exactly one wins, the durable revision ends at
exactly 1 (not higher, which a stale winner slipping through would
produce), and every loser fails cleanly rather than hanging or
returning a raw serialization error. Stable across 6 runs with -race,
plus the full integration and unit suites.
Races 5 concurrent identical CompleteResultWithResult calls for the
same RESULT_PENDING match against a real PostgreSQL instance -- the
scenario behind 8.25's 'identical duplicates idempotent' claim, which
every existing result test only exercised sequentially. All five must
succeed (idempotent replay, not conflict), and the rating update must
apply exactly once: asserted by computing the expected post-match
rating independently via the same domain.CasualOpponents/UpdateRating
functions and requiring an exact match, since a doubled application
would compound the rating further away from baseline rather than
merely producing 'some' change that a looser inequality check would
miss.
First draft asserted ranked_games == 1, which doesn't hold for a
casual result (rankedIncrement is unconditionally 0 for casual by
design) -- caught by actually running it, not by inspection. Verified
clean across 6 runs with -race, plus the full integration and unit
suites.
Fires more concurrent ClaimAllocation calls than there is Ready
capacity at a real PostgreSQL instance and asserts: exactly as many
win as there was capacity, every winner gets a distinct server (no
double-booking), every loser gets ErrNoCapacity rather than a raw
serialization error or a hang, and the durable game_servers.state
count matches. This is the cross-allocator-replica race 8.30 calls
out as untested -- the existing capacity test in this file claims
strictly one request at a time. Verified clean across 6 runs with
-race, plus the full integration and unit suites.
Every existing Postgres integration test runs strictly one transaction
at a time, so none of them exercise the SERIALIZABLE retry-and-fence
path CreateProposal actually depends on for correctness under real
matcher-replica contention -- only concurrent goroutines against a
real connection can. Add a test that races two goroutines each
proposing a formation that shares one contested ticket (a realistic
scenario: nothing stops two matcher replicas reading the same QUEUED
ticket in the same poll window), and asserts exactly one proposal
commits, the loser's proposal and participant rows are fully rolled
back, the contested ticket ends up claimed by the winner, and -- the
part a single-threaded test can't show -- the loser's OWN uncontested
ticket also rolls back to QUEUED rather than being left stranded as
PROPOSED with no surviving proposal.
Adversarial review of my own first draft: it initially failed
deterministically (5/5 runs), but the failure was in the test itself
-- the winner/loser branch picking the loser's uncontested ticket had
the two branches swapped, so it was checking the WINNER's ticket
against the QUEUED expectation. Fixed and re-verified clean across 8
runs with -race, plus the full integration suite.
ranked_season_rollovers.season_id has a foreign key into seasons, but
the integration test never inserted a seasons row for 'season-1' --
ApplyRankedSeasonRollover failed on the FK constraint before the
rollover logic itself ran at all. Insert a matching seasons row,
mirroring how a real 12-week season would already exist when
maintenance's rollover sweep runs. Verified against a real
PostgreSQL instance.
Add migrations.Rollback(ctx, db, dir, steps): reverses the N most
recently applied migrations, newest first, each in its own committed
transaction under the same advisory lock Apply uses. Down SQL lives in
migrations/down/<version>.sql (a subdirectory, so Apply's *.sql glob
over the main directory is untouched); a missing down file for a
migration being rolled back is a hard error rather than a silent
partial reversal. Wire it into cmd/migrate as --rollback=N.
Add down files for all six existing migrations, each dropping objects
in FK-safe reverse dependency order.
Adversarial review: could not run the new integration test
(TestPostgreSQLMigrationsRollBackAndReapplyCleanly, gated behind
COSMIC_CLASH_POSTGRES_DSN / scripts/run_postgres_integration.sh)
against a real database in this sandbox - Docker Desktop's own
overlayfs ran out of space pulling postgres:17-alpine, unrelated to
this change. Verified instead by hand-tracing every DROP against its
forward migration's FK graph, confirming Apply's directory glob does
not pick up the down/ subdirectory, and a clean go build/vet/test
-tags integration. Worth an explicit real run before this is trusted
in CI.
Josh Creek