88 lines
2.1 KiB
Go
88 lines
2.1 KiB
Go
// Copyright 2023 The Prometheus Authors
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package collector
|
|
|
|
import (
|
|
"context"
|
|
"database/sql"
|
|
|
|
"github.com/prometheus/client_golang/prometheus"
|
|
)
|
|
|
|
const replicationSubsystem = "replication"
|
|
|
|
func init() {
|
|
registerCollector(replicationSubsystem, defaultEnabled, NewPGReplicationCollector)
|
|
}
|
|
|
|
type PGReplicationCollector struct {
|
|
}
|
|
|
|
func NewPGReplicationCollector(collectorConfig) (Collector, error) {
|
|
return &PGPostmasterCollector{}, nil
|
|
}
|
|
|
|
var (
|
|
pgReplicationLag = prometheus.NewDesc(
|
|
prometheus.BuildFQName(
|
|
namespace,
|
|
replicationSubsystem,
|
|
"lag_seconds",
|
|
),
|
|
"Replication lag behind master in seconds",
|
|
[]string{}, nil,
|
|
)
|
|
pgReplicationIsReplica = prometheus.NewDesc(
|
|
prometheus.BuildFQName(
|
|
namespace,
|
|
replicationSubsystem,
|
|
"is_replica",
|
|
),
|
|
"Indicates if the server is a replica",
|
|
[]string{}, nil,
|
|
)
|
|
|
|
pgReplicationQuery = `SELECT
|
|
CASE
|
|
WHEN NOT pg_is_in_recovery() THEN 0
|
|
ELSE GREATEST (0, EXTRACT(EPOCH FROM (now() - pg_last_xact_replay_timestamp())))
|
|
END AS lag,
|
|
CASE
|
|
WHEN pg_is_in_recovery() THEN 1
|
|
ELSE 0
|
|
END as is_replica`
|
|
)
|
|
|
|
func (c *PGReplicationCollector) Update(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
|
|
row := db.QueryRowContext(ctx,
|
|
pgReplicationQuery,
|
|
)
|
|
|
|
var lag float64
|
|
var isReplica int64
|
|
err := row.Scan(&lag, &isReplica)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
ch <- prometheus.MustNewConstMetric(
|
|
pgReplicationLag,
|
|
prometheus.GaugeValue, lag,
|
|
)
|
|
ch <- prometheus.MustNewConstMetric(
|
|
pgReplicationIsReplica,
|
|
prometheus.GaugeValue, float64(isReplica),
|
|
)
|
|
return nil
|
|
}
|