ceph_exporter/collectors/pool_usage.go

254 lines
7.1 KiB
Go

// Copyright 2016 DigitalOcean
//
// 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 collectors
import (
"encoding/json"
"errors"
"log"
"github.com/prometheus/client_golang/prometheus"
)
// PoolUsageCollector displays statistics about each pool we have created
// in the ceph cluster.
type PoolUsageCollector struct {
conn Conn
// UsedBytes tracks the amount of bytes currently allocated for the pool. This
// does not factor in the overcommitment made for individual images.
UsedBytes *prometheus.GaugeVec
// RawUsedBytes tracks the amount of raw bytes currently used for the pool. This
// factors in the replication factor (size) of the pool.
RawUsedBytes *prometheus.GaugeVec
// MaxAvail tracks the amount of bytes currently free for the pool,
// which depends on the replication settings for the pool in question.
MaxAvail *prometheus.GaugeVec
// Objects shows the no. of RADOS objects created within the pool.
Objects *prometheus.GaugeVec
// DirtyObjects shows the no. of RADOS dirty objects in a cache-tier pool,
// this doesn't make sense in a regular pool, see:
// http://lists.ceph.com/pipermail/ceph-users-ceph.com/2015-April/000557.html
DirtyObjects *prometheus.GaugeVec
// ReadIO tracks the read IO calls made for the images within each pool.
ReadIO *prometheus.GaugeVec
// Readbytes tracks the read throughput made for the images within each pool.
ReadBytes *prometheus.GaugeVec
// WriteIO tracks the write IO calls made for the images within each pool.
WriteIO *prometheus.GaugeVec
// WriteBytes tracks the write throughput made for the images within each pool.
WriteBytes *prometheus.GaugeVec
}
// NewPoolUsageCollector creates a new instance of PoolUsageCollector and returns
// its reference.
func NewPoolUsageCollector(conn Conn) *PoolUsageCollector {
var (
subSystem = "pool"
poolLabel = []string{"pool"}
)
return &PoolUsageCollector{
conn: conn,
UsedBytes: prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: cephNamespace,
Subsystem: subSystem,
Name: "used_bytes",
Help: "Capacity of the pool that is currently under use",
},
poolLabel,
),
RawUsedBytes: prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: cephNamespace,
Subsystem: subSystem,
Name: "raw_used_bytes",
Help: "Raw capacity of the pool that is currently under use, this factors in the size",
},
poolLabel,
),
MaxAvail: prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: cephNamespace,
Subsystem: subSystem,
Name: "available_bytes",
Help: "Free space for this ceph pool",
},
poolLabel,
),
Objects: prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: cephNamespace,
Subsystem: subSystem,
Name: "objects_total",
Help: "Total no. of objects allocated within the pool",
},
poolLabel,
),
DirtyObjects: prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: cephNamespace,
Subsystem: subSystem,
Name: "dirty_objects_total",
Help: "Total no. of dirty objects in a cache-tier pool",
},
poolLabel,
),
ReadIO: prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: cephNamespace,
Subsystem: subSystem,
Name: "read_total",
Help: "Total read i/o calls for the pool",
},
poolLabel,
),
ReadBytes: prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: cephNamespace,
Subsystem: subSystem,
Name: "read_bytes_total",
Help: "Total read throughput for the pool",
},
poolLabel,
),
WriteIO: prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: cephNamespace,
Subsystem: subSystem,
Name: "write_total",
Help: "Total write i/o calls for the pool",
},
poolLabel,
),
WriteBytes: prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: cephNamespace,
Subsystem: subSystem,
Name: "write_bytes_total",
Help: "Total write throughput for the pool",
},
poolLabel,
),
}
}
func (p *PoolUsageCollector) collectorList() []prometheus.Collector {
return []prometheus.Collector{
p.UsedBytes,
p.RawUsedBytes,
p.MaxAvail,
p.Objects,
p.DirtyObjects,
p.ReadIO,
p.ReadBytes,
p.WriteIO,
p.WriteBytes,
}
}
type cephPoolStats struct {
Pools []struct {
Name string `json:"name"`
ID int `json:"id"`
Stats struct {
BytesUsed float64 `json:"bytes_used"`
RawBytesUsed float64 `json:"raw_bytes_used"`
MaxAvail float64 `json:"max_avail"`
Objects float64 `json:"objects"`
DirtyObjects float64 `json:"dirty"`
ReadIO float64 `json:"rd"`
ReadBytes float64 `json:"rd_bytes"`
WriteIO float64 `json:"wr"`
WriteBytes float64 `json:"wr_bytes"`
} `json:"stats"`
} `json:"pools"`
}
func (p *PoolUsageCollector) collect() error {
cmd := p.cephUsageCommand()
buf, _, err := p.conn.MonCommand(cmd)
if err != nil {
return err
}
stats := &cephPoolStats{}
if err := json.Unmarshal(buf, stats); err != nil {
return err
}
if len(stats.Pools) < 1 {
return errors.New("no pools found in the cluster to report stats on")
}
for _, pool := range stats.Pools {
p.UsedBytes.WithLabelValues(pool.Name).Set(pool.Stats.BytesUsed)
p.RawUsedBytes.WithLabelValues(pool.Name).Set(pool.Stats.RawBytesUsed)
p.MaxAvail.WithLabelValues(pool.Name).Set(pool.Stats.MaxAvail)
p.Objects.WithLabelValues(pool.Name).Set(pool.Stats.Objects)
p.DirtyObjects.WithLabelValues(pool.Name).Set(pool.Stats.DirtyObjects)
p.ReadIO.WithLabelValues(pool.Name).Set(pool.Stats.ReadIO)
p.ReadBytes.WithLabelValues(pool.Name).Set(pool.Stats.ReadBytes)
p.WriteIO.WithLabelValues(pool.Name).Set(pool.Stats.WriteIO)
p.WriteBytes.WithLabelValues(pool.Name).Set(pool.Stats.WriteBytes)
}
return nil
}
func (p *PoolUsageCollector) cephUsageCommand() []byte {
cmd, err := json.Marshal(map[string]interface{}{
"prefix": "df",
"detail": "detail",
"format": "json",
})
if err != nil {
// panic! because ideally in no world this hard-coded input
// should fail.
panic(err)
}
return cmd
}
// Describe fulfills the prometheus.Collector's interface and sends the descriptors
// of pool's metrics to the given channel.
func (p *PoolUsageCollector) Describe(ch chan<- *prometheus.Desc) {
for _, metric := range p.collectorList() {
metric.Describe(ch)
}
}
// Collect extracts the current values of all the metrics and sends them to the
// prometheus channel.
func (p *PoolUsageCollector) Collect(ch chan<- prometheus.Metric) {
if err := p.collect(); err != nil {
log.Println("[ERROR] failed collecting pool usage metrics:", err)
return
}
for _, metric := range p.collectorList() {
metric.Collect(ch)
}
}