github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/cdc/metrics/metrics.go (about)

     1  // Copyright 2020 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package metrics
    15  
    16  import (
    17  	"github.com/prometheus/client_golang/prometheus"
    18  )
    19  
    20  // LagBucket returns the lag buckets for prometheus metric
    21  // 10 seconds is the reasonable LAG for most cases,
    22  // for prometheus histogram_quantile func,
    23  // we use small bucket distance to do accurate approximation
    24  func LagBucket() []float64 {
    25  	// 0.5s-10s in step of 0.5s
    26  	buckets := prometheus.LinearBuckets(0.5, 0.5, 20)
    27  	// 11s-20s in step of 1s
    28  	buckets = append(buckets, prometheus.LinearBuckets(11, 1, 10)...)
    29  	// 21s-591s in step of 30s
    30  	buckets = append(buckets, prometheus.LinearBuckets(21, 30, 20)...)
    31  	// 900s-3600 in step of 300s
    32  	buckets = append(buckets, prometheus.LinearBuckets(900, 300, 10)...)
    33  	// [4000, 8000, 16000, 32000]
    34  	buckets = append(buckets, prometheus.ExponentialBuckets(4000, 2, 4)...)
    35  	return buckets
    36  }