fix(projection): prevent skipped events written within the same microsecond (#10710)

This PR fixes a bug where projections could skip events if they were
written within the same microsecond, which can occur during high load on
different transactions.

## Problem

The event query ordering was not fully deterministic. Events created at
the exact same time (same `position`) and in the same transaction
(`in_tx_order`) were not guaranteed to be returned in the same order on
subsequent queries. This could lead to some events being skipped by the
projection logic.

## Solution

To solve this, the `ORDER BY` clause for event queries has been extended
to include `instance_id`, `aggregate_type`, and `aggregate_id`. This
ensures a stable and deterministic ordering for all events, even if they
share the same timestamp.

## Additionally changes:

* Replaced a manual slice search with the more idiomatic
`slices.Contains` to skip already projected instances.
* Changed the handling of already locked projections to log a debug
message and skip execution instead of returning an error.
* Ensures the database transaction is explicitly committed.
This commit is contained in:
Silvan
2025-09-12 14:26:03 +03:00
committed by GitHub
parent 25d921b20c
commit 25ab6b2397
3 changed files with 12 additions and 17 deletions
@@ -903,7 +903,7 @@ func Test_query_events_mocked(t *testing.T) {
},
fields: fields{
mock: newMockClient(t).expectQuery(
regexp.QuoteMeta(`SELECT created_at, event_type, "sequence", "position", payload, creator, "owner", instance_id, aggregate_type, aggregate_id, revision FROM eventstore.events2 WHERE instance_id = $1 AND aggregate_type = $2 AND event_type = $3 AND "position" >= $4 AND aggregate_id NOT IN (SELECT aggregate_id FROM eventstore.events2 WHERE aggregate_type = $5 AND event_type = ANY($6) AND instance_id = $7 AND "position" >= $8) ORDER BY "position" DESC, in_tx_order DESC LIMIT $9`),
regexp.QuoteMeta(`SELECT created_at, event_type, "sequence", "position", payload, creator, "owner", instance_id, aggregate_type, aggregate_id, revision FROM eventstore.events2 WHERE instance_id = $1 AND aggregate_type = $2 AND event_type = $3 AND "position" >= $4 AND aggregate_id NOT IN (SELECT aggregate_id FROM eventstore.events2 WHERE aggregate_type = $5 AND event_type = ANY($6) AND instance_id = $7 AND "position" >= $8) ORDER BY "position" DESC, in_tx_order DESC, instance_id, aggregate_type, aggregate_id LIMIT $9`),
[]driver.Value{"instanceID", eventstore.AggregateType("notify"), eventstore.EventType("notify.foo.bar"), decimal.NewFromFloat(123.456), eventstore.AggregateType("notify"), []eventstore.EventType{"notification.failed", "notification.success"}, "instanceID", decimal.NewFromFloat(123.456), uint64(5)},
),
},
@@ -932,7 +932,7 @@ func Test_query_events_mocked(t *testing.T) {
},
fields: fields{
mock: newMockClient(t).expectQuery(
regexp.QuoteMeta(`SELECT created_at, event_type, "sequence", "position", payload, creator, "owner", instance_id, aggregate_type, aggregate_id, revision FROM eventstore.events2 WHERE instance_id = $1 AND aggregate_type = $2 AND event_type = $3 AND created_at > $4 AND aggregate_id NOT IN (SELECT aggregate_id FROM eventstore.events2 WHERE aggregate_type = $5 AND event_type = ANY($6) AND instance_id = $7 AND created_at > $8) ORDER BY "position" DESC, in_tx_order DESC LIMIT $9`),
regexp.QuoteMeta(`SELECT created_at, event_type, "sequence", "position", payload, creator, "owner", instance_id, aggregate_type, aggregate_id, revision FROM eventstore.events2 WHERE instance_id = $1 AND aggregate_type = $2 AND event_type = $3 AND created_at > $4 AND aggregate_id NOT IN (SELECT aggregate_id FROM eventstore.events2 WHERE aggregate_type = $5 AND event_type = ANY($6) AND instance_id = $7 AND created_at > $8) ORDER BY "position" DESC, in_tx_order DESC, instance_id, aggregate_type, aggregate_id LIMIT $9`),
[]driver.Value{"instanceID", eventstore.AggregateType("notify"), eventstore.EventType("notify.foo.bar"), time.Unix(123, 456), eventstore.AggregateType("notify"), []eventstore.EventType{"notification.failed", "notification.success"}, "instanceID", time.Unix(123, 456), uint64(5)},
),
},