mirror of
https://github.com/zitadel/zitadel.git
synced 2025-12-23 10:27:21 +00:00
0575f67e94
This PR overhauls our event projection system to make it more robust and prevent skipped events under high load. The core change replaces our custom, transaction-based locking with standard PostgreSQL advisory locks. We also introduce a worker pool to manage concurrency and prevent database connection exhaustion. ### Key Changes * **Advisory Locks for Projections:** Replaces exclusive row locks and inspection of `pg_stat_activity` with PostgreSQL advisory locks for managing projection state. This is a more reliable and standard approach to distributed locking. * **Simplified Await Logic:** Removes the complex logic for awaiting open transactions, simplifying it to a more straightforward time-based filtering of events. * **Projection Worker Pool:** Implements a worker pool to limit concurrent projection triggers, preventing connection exhaustion and improving stability under load. A new `MaxParallelTriggers` configuration option is introduced. ### Problem Solved Under high throughput, a race condition could cause projections to miss events from the eventstore. This led to inconsistent data in projection tables (e.g., a user grant might be missing). This PR fixes the underlying locking and concurrency issues to ensure all events are processed reliably. ### How it Works 1. **Event Writing:** When writing events, a *shared* advisory lock is taken. This signals that a write is in progress. 2. **Event Handling (Projections):** * A projection worker attempts to acquire an *exclusive* advisory lock for that specific projection. If the lock is already held, it means another worker is on the job, so the current one backs off. * Once the lock is acquired, the worker briefly acquires and releases the same *shared* lock used by event writers. This acts as a barrier, ensuring it waits for any in-flight writes to complete. * Finally, it processes all events that occurred before its transaction began. ### Additional Information * ZITADEL no longer modifies the `application_name` PostgreSQL variable during event writes. * The lock on the `current_states` table is now `FOR NO KEY UPDATE`. * Fixes https://github.com/zitadel/zitadel/issues/8509 --------- Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> Co-authored-by: Tim Möhlmann <tim+github@zitadel.com>
32 lines
722 B
Go
32 lines
722 B
Go
package projection
|
|
|
|
import (
|
|
"time"
|
|
)
|
|
|
|
type Config struct {
|
|
RequeueEvery time.Duration
|
|
RetryFailedAfter time.Duration
|
|
MaxFailureCount uint8
|
|
ConcurrentInstances uint
|
|
BulkLimit uint64
|
|
Customizations map[string]CustomConfig
|
|
HandleActiveInstances time.Duration
|
|
MaxActiveInstances uint32
|
|
TransactionDuration time.Duration
|
|
ActiveInstancer interface {
|
|
ActiveInstances() []string
|
|
}
|
|
MaxParallelTriggers uint16
|
|
}
|
|
|
|
type CustomConfig struct {
|
|
RequeueEvery *time.Duration
|
|
RetryFailedAfter *time.Duration
|
|
MaxFailureCount *uint8
|
|
ConcurrentInstances *uint
|
|
BulkLimit *uint16
|
|
TransactionDuration *time.Duration
|
|
SkipInstanceIDs []string
|
|
}
|