forked from prometheus/prometheus
-
Notifications
You must be signed in to change notification settings - Fork 0
/
targetmanager.go
172 lines (137 loc) · 4.34 KB
/
targetmanager.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
// Copyright 2013 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 retrieval
import (
"sync"
"github.com/go-kit/kit/log"
"github.com/go-kit/kit/log/level"
"golang.org/x/net/context"
"github.com/prometheus/prometheus/config"
"github.com/prometheus/prometheus/discovery"
"github.com/prometheus/prometheus/storage"
)
// TargetManager maintains a set of targets, starts and stops their scraping and
// creates the new targets based on the target groups it receives from various
// target providers.
type TargetManager struct {
append Appendable
scrapeConfigs []*config.ScrapeConfig
mtx sync.RWMutex
ctx context.Context
cancel func()
wg sync.WaitGroup
// Set of unqiue targets by scrape configuration.
targetSets map[string]*targetSet
logger log.Logger
}
type targetSet struct {
ctx context.Context
cancel func()
ts *discovery.TargetSet
sp *scrapePool
}
type Appendable interface {
Appender() (storage.Appender, error)
}
// NewTargetManager creates a new TargetManager.
func NewTargetManager(app Appendable, logger log.Logger) *TargetManager {
return &TargetManager{
append: app,
targetSets: map[string]*targetSet{},
logger: logger,
}
}
// Run starts background processing to handle target updates.
func (tm *TargetManager) Run() {
level.Info(tm.logger).Log("msg", "Starting target manager...")
tm.mtx.Lock()
tm.ctx, tm.cancel = context.WithCancel(context.Background())
tm.reload()
tm.mtx.Unlock()
tm.wg.Wait()
}
// Stop all background processing.
func (tm *TargetManager) Stop() {
level.Info(tm.logger).Log("msg", "Stopping target manager...")
tm.mtx.Lock()
// Cancel the base context, this will cause all target providers to shut down
// and all in-flight scrapes to abort immmediately.
// Started inserts will be finished before terminating.
tm.cancel()
tm.mtx.Unlock()
// Wait for all scrape inserts to complete.
tm.wg.Wait()
level.Info(tm.logger).Log("msg", "Target manager stopped")
}
func (tm *TargetManager) reload() {
jobs := map[string]struct{}{}
// Start new target sets and update existing ones.
for _, scfg := range tm.scrapeConfigs {
jobs[scfg.JobName] = struct{}{}
ts, ok := tm.targetSets[scfg.JobName]
if !ok {
ctx, cancel := context.WithCancel(tm.ctx)
ts = &targetSet{
ctx: ctx,
cancel: cancel,
sp: newScrapePool(ctx, scfg, tm.append, log.With(tm.logger, "scrape_pool", scfg.JobName)),
}
ts.ts = discovery.NewTargetSet(ts.sp)
tm.targetSets[scfg.JobName] = ts
tm.wg.Add(1)
go func(ts *targetSet) {
// Run target set, which blocks until its context is canceled.
// Gracefully shut down pending scrapes in the scrape pool afterwards.
ts.ts.Run(ctx)
ts.sp.stop()
tm.wg.Done()
}(ts)
} else {
ts.sp.reload(scfg)
}
ts.ts.UpdateProviders(discovery.ProvidersFromConfig(scfg.ServiceDiscoveryConfig, tm.logger))
}
// Remove old target sets. Waiting for scrape pools to complete pending
// scrape inserts is already guaranteed by the goroutine that started the target set.
for name, ts := range tm.targetSets {
if _, ok := jobs[name]; !ok {
ts.cancel()
delete(tm.targetSets, name)
}
}
}
// Targets returns the targets currently being scraped.
func (tm *TargetManager) Targets() []*Target {
tm.mtx.RLock()
defer tm.mtx.RUnlock()
targets := []*Target{}
for _, ps := range tm.targetSets {
ps.sp.mtx.RLock()
for _, t := range ps.sp.targets {
targets = append(targets, t)
}
ps.sp.mtx.RUnlock()
}
return targets
}
// ApplyConfig resets the manager's target providers and job configurations as defined
// by the new cfg. The state of targets that are valid in the new configuration remains unchanged.
func (tm *TargetManager) ApplyConfig(cfg *config.Config) error {
tm.mtx.Lock()
defer tm.mtx.Unlock()
tm.scrapeConfigs = cfg.ScrapeConfigs
if tm.ctx != nil {
tm.reload()
}
return nil
}