prometheus/retrieval/targetmanager.go
Julius Volz f1fc7d717a Allow replacing job targets via HTTP API.
This roughly comprises the following changes:

- index target pools by job instead of scrape interval
- make targets within a pool exchangable while preserving existing
  health state for targets
- allow exchanging targets via HTTP API (PUT)
- show target lists in /status (experimental, for own debug use)
2013-02-28 21:33:29 +01:00

110 lines
3.2 KiB
Go

// Copyright 2013 Prometheus Team
// 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 (
"github.com/prometheus/prometheus/config"
"github.com/prometheus/prometheus/model"
"github.com/prometheus/prometheus/retrieval/format"
"log"
"time"
)
type TargetManager interface {
acquire()
release()
AddTarget(job *config.JobConfig, t Target, defaultScrapeInterval time.Duration)
ReplaceTargets(job *config.JobConfig, newTargets []Target, defaultScrapeInterval time.Duration)
Remove(t Target)
AddTargetsFromConfig(config *config.Config)
Pools() map[string]*TargetPool
}
type targetManager struct {
requestAllowance chan bool
poolsByJob map[string]*TargetPool
results chan format.Result
}
func NewTargetManager(results chan format.Result, requestAllowance int) TargetManager {
return &targetManager{
requestAllowance: make(chan bool, requestAllowance),
results: results,
poolsByJob: make(map[string]*TargetPool),
}
}
func (m *targetManager) acquire() {
m.requestAllowance <- true
}
func (m *targetManager) release() {
<-m.requestAllowance
}
func (m *targetManager) TargetPoolForJob(job *config.JobConfig, defaultScrapeInterval time.Duration) (targetPool *TargetPool) {
targetPool, ok := m.poolsByJob[job.Name]
if !ok {
targetPool = NewTargetPool(m)
log.Printf("Pool for job %s does not exist; creating and starting...", job.Name)
interval := job.ScrapeInterval
if interval == 0 {
interval = defaultScrapeInterval
}
m.poolsByJob[job.Name] = targetPool
go targetPool.Run(m.results, interval)
}
return
}
func (m *targetManager) AddTarget(job *config.JobConfig, t Target, defaultScrapeInterval time.Duration) {
targetPool := m.TargetPoolForJob(job, defaultScrapeInterval)
targetPool.AddTarget(t)
m.poolsByJob[job.Name] = targetPool
}
func (m *targetManager) ReplaceTargets(job *config.JobConfig, newTargets []Target, defaultScrapeInterval time.Duration) {
targetPool := m.TargetPoolForJob(job, defaultScrapeInterval)
targetPool.replaceTargets(newTargets)
}
func (m targetManager) Remove(t Target) {
panic("not implemented")
}
func (m *targetManager) AddTargetsFromConfig(config *config.Config) {
for _, job := range config.Jobs {
for _, configTargets := range job.Targets {
baseLabels := model.LabelSet{
model.LabelName("job"): model.LabelValue(job.Name),
}
for label, value := range configTargets.Labels {
baseLabels[label] = value
}
for _, endpoint := range configTargets.Endpoints {
target := NewTarget(endpoint, time.Second*5, baseLabels)
m.AddTarget(&job, target, config.Global.ScrapeInterval)
}
}
}
}
// XXX: Not really thread-safe. Only used in /status page for now.
func (m *targetManager) Pools() map[string]*TargetPool {
return m.poolsByJob
}