74 lines
1.9 KiB
Go
74 lines
1.9 KiB
Go
package pgmapbroker
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/centrifugal/centrifugo/v6/internal/metrics"
|
|
)
|
|
|
|
// mapMetricsSampler periodically samples PG-specific gauge metrics: outbox
|
|
// cursor lag per shard and partition count on the stream table.
|
|
type mapMetricsSampler struct {
|
|
broker *PostgresMapBroker
|
|
mu sync.Mutex
|
|
cursorByShard map[int]int64
|
|
}
|
|
|
|
func newMapMetricsSampler(b *PostgresMapBroker) *mapMetricsSampler {
|
|
return &mapMetricsSampler{
|
|
broker: b,
|
|
cursorByShard: make(map[int]int64),
|
|
}
|
|
}
|
|
|
|
func (s *mapMetricsSampler) storeCursor(shard int, cursor int64) {
|
|
s.mu.Lock()
|
|
s.cursorByShard[shard] = cursor
|
|
s.mu.Unlock()
|
|
}
|
|
|
|
func (s *mapMetricsSampler) sample(ctx context.Context) {
|
|
if metrics.MapBrokerPostgresPartitions == nil {
|
|
return
|
|
}
|
|
brokerName := s.broker.conf.Name
|
|
|
|
// Sample partition count on the stream table.
|
|
var partitionCount int
|
|
err := s.broker.pool.QueryRow(ctx, `
|
|
SELECT COUNT(*) FROM pg_inherits i
|
|
JOIN pg_class c ON c.oid = i.inhparent
|
|
WHERE c.relname = $1
|
|
`, s.broker.names.stream).Scan(&partitionCount)
|
|
if err == nil {
|
|
metrics.MapBrokerPostgresPartitions.WithLabelValues(brokerName).Set(float64(partitionCount))
|
|
}
|
|
|
|
// Sample cursor lag per shard.
|
|
s.mu.Lock()
|
|
cursors := make(map[int]int64, len(s.cursorByShard))
|
|
for k, v := range s.cursorByShard {
|
|
cursors[k] = v
|
|
}
|
|
s.mu.Unlock()
|
|
for shard, cursor := range cursors {
|
|
var createdAt time.Time
|
|
err := s.broker.pool.QueryRow(ctx, fmt.Sprintf(
|
|
`SELECT created_at FROM %s WHERE id = $1 LIMIT 1`,
|
|
s.broker.names.stream,
|
|
), cursor).Scan(&createdAt)
|
|
if err != nil {
|
|
metrics.MapBrokerPostgresOutboxCursorLagSeconds.WithLabelValues(brokerName, fmt.Sprintf("%d", shard)).Set(0)
|
|
continue
|
|
}
|
|
lag := time.Since(createdAt).Seconds()
|
|
if lag < 0 {
|
|
lag = 0
|
|
}
|
|
metrics.MapBrokerPostgresOutboxCursorLagSeconds.WithLabelValues(brokerName, fmt.Sprintf("%d", shard)).Set(lag)
|
|
}
|
|
}
|