70 lines
1.8 KiB
Go
70 lines
1.8 KiB
Go
// Copyright 2023 The Prometheus Authors
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package collector
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import (
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"context"
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"database/sql"
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"github.com/prometheus/client_golang/prometheus"
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)
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const postmasterSubsystem = "postmaster"
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func init() {
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registerCollector(postmasterSubsystem, defaultEnabled, NewPGPostmasterCollector)
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}
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type PGPostmasterCollector struct {
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}
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func NewPGPostmasterCollector(collectorConfig) (Collector, error) {
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return &PGPostmasterCollector{}, nil
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}
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var (
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pgPostMasterStartTimeSeconds = prometheus.NewDesc(
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prometheus.BuildFQName(
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namespace,
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postmasterSubsystem,
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"start_time_seconds",
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),
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"Time at which postmaster started",
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[]string{}, nil,
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)
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pgPostmasterQuery = "SELECT pg_postmaster_start_time from pg_postmaster_start_time();"
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)
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func (c *PGPostmasterCollector) Update(ctx context.Context, instance *instance, ch chan<- prometheus.Metric) error {
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db := instance.getDB()
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row := db.QueryRowContext(ctx,
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pgPostmasterQuery)
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var startTimeSeconds sql.NullFloat64
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err := row.Scan(&startTimeSeconds)
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if err != nil {
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return err
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}
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startTimeSecondsMetric := 0.0
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if startTimeSeconds.Valid {
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startTimeSecondsMetric = startTimeSeconds.Float64
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}
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ch <- prometheus.MustNewConstMetric(
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pgPostMasterStartTimeSeconds,
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prometheus.GaugeValue, startTimeSecondsMetric,
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)
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return nil
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}
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