statsd_exporter/pkg/mapper/mapper.go
Andy Paine 0135b40c08 Make mapper cache respect metric type
- Statsd allows users to provide a metric with the same name but
  differing types (counter, gauge, timer)
- The exporter allows this by letting users specify a
  "match_metric_type" in the mapping config
- However the mapper cache does not look at the metric type so it would
  return a MetricMapperCacheResult for the type of the first metric with
that name that the exporter saw
- Add MetricType to the signature for the cache and format the metric
  name with the type to provide unique keys for a metric with the same
name but differing type

Signed-off-by: Andy Paine <andy.paine@digital.cabinet-office.gov.uk>
2019-06-06 11:33:58 +01:00

301 lines
8.5 KiB
Go

// 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 mapper
import (
"fmt"
"io/ioutil"
"regexp"
"sync"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/log"
"github.com/prometheus/statsd_exporter/pkg/mapper/fsm"
yaml "gopkg.in/yaml.v2"
"time"
)
var (
statsdMetricRE = `[a-zA-Z_](-?[a-zA-Z0-9_])+`
templateReplaceRE = `(\$\{?\d+\}?)`
metricLineRE = regexp.MustCompile(`^(\*\.|` + statsdMetricRE + `\.)+(\*|` + statsdMetricRE + `)$`)
metricNameRE = regexp.MustCompile(`^([a-zA-Z_]|` + templateReplaceRE + `)([a-zA-Z0-9_]|` + templateReplaceRE + `)*$`)
labelNameRE = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_]+$`)
)
type mapperConfigDefaults struct {
TimerType TimerType `yaml:"timer_type"`
Buckets []float64 `yaml:"buckets"`
Quantiles []metricObjective `yaml:"quantiles"`
MatchType MatchType `yaml:"match_type"`
GlobDisableOrdering bool `yaml:"glob_disable_ordering"`
Ttl time.Duration `yaml:"ttl"`
}
type MetricMapper struct {
Defaults mapperConfigDefaults `yaml:"defaults"`
Mappings []MetricMapping `yaml:"mappings"`
FSM *fsm.FSM
doFSM bool
doRegex bool
cache MetricMapperCache
mutex sync.RWMutex
MappingsCount prometheus.Gauge
}
type MetricMapping struct {
Match string `yaml:"match"`
Name string `yaml:"name"`
nameFormatter *fsm.TemplateFormatter
regex *regexp.Regexp
Labels prometheus.Labels `yaml:"labels"`
labelKeys []string
labelFormatters []*fsm.TemplateFormatter
TimerType TimerType `yaml:"timer_type"`
Buckets []float64 `yaml:"buckets"`
Quantiles []metricObjective `yaml:"quantiles"`
MatchType MatchType `yaml:"match_type"`
HelpText string `yaml:"help"`
Action ActionType `yaml:"action"`
MatchMetricType MetricType `yaml:"match_metric_type"`
Ttl time.Duration `yaml:"ttl"`
}
type metricObjective struct {
Quantile float64 `yaml:"quantile"`
Error float64 `yaml:"error"`
}
var defaultQuantiles = []metricObjective{
{Quantile: 0.5, Error: 0.05},
{Quantile: 0.9, Error: 0.01},
{Quantile: 0.99, Error: 0.001},
}
func (m *MetricMapper) InitFromYAMLString(fileContents string, cacheSize int) error {
var n MetricMapper
if err := yaml.Unmarshal([]byte(fileContents), &n); err != nil {
return err
}
if n.Defaults.Buckets == nil || len(n.Defaults.Buckets) == 0 {
n.Defaults.Buckets = prometheus.DefBuckets
}
if n.Defaults.Quantiles == nil || len(n.Defaults.Quantiles) == 0 {
n.Defaults.Quantiles = defaultQuantiles
}
if n.Defaults.MatchType == MatchTypeDefault {
n.Defaults.MatchType = MatchTypeGlob
}
remainingMappingsCount := len(n.Mappings)
n.FSM = fsm.NewFSM([]string{string(MetricTypeCounter), string(MetricTypeGauge), string(MetricTypeTimer)},
remainingMappingsCount, n.Defaults.GlobDisableOrdering)
for i := range n.Mappings {
remainingMappingsCount--
currentMapping := &n.Mappings[i]
// check that label is correct
for k := range currentMapping.Labels {
if !labelNameRE.MatchString(k) {
return fmt.Errorf("invalid label key: %s", k)
}
}
if currentMapping.Name == "" {
return fmt.Errorf("line %d: metric mapping didn't set a metric name", i)
}
if !metricNameRE.MatchString(currentMapping.Name) {
return fmt.Errorf("metric name '%s' doesn't match regex '%s'", currentMapping.Name, metricNameRE)
}
if currentMapping.MatchType == "" {
currentMapping.MatchType = n.Defaults.MatchType
}
if currentMapping.Action == "" {
currentMapping.Action = ActionTypeMap
}
if currentMapping.MatchType == MatchTypeGlob {
n.doFSM = true
if !metricLineRE.MatchString(currentMapping.Match) {
return fmt.Errorf("invalid match: %s", currentMapping.Match)
}
captureCount := n.FSM.AddState(currentMapping.Match, string(currentMapping.MatchMetricType),
remainingMappingsCount, currentMapping)
currentMapping.nameFormatter = fsm.NewTemplateFormatter(currentMapping.Name, captureCount)
labelKeys := make([]string, len(currentMapping.Labels))
labelFormatters := make([]*fsm.TemplateFormatter, len(currentMapping.Labels))
labelIndex := 0
for label, valueExpr := range currentMapping.Labels {
labelKeys[labelIndex] = label
labelFormatters[labelIndex] = fsm.NewTemplateFormatter(valueExpr, captureCount)
labelIndex++
}
currentMapping.labelFormatters = labelFormatters
currentMapping.labelKeys = labelKeys
} else {
if regex, err := regexp.Compile(currentMapping.Match); err != nil {
return fmt.Errorf("invalid regex %s in mapping: %v", currentMapping.Match, err)
} else {
currentMapping.regex = regex
}
n.doRegex = true
}
if currentMapping.TimerType == "" {
currentMapping.TimerType = n.Defaults.TimerType
}
if currentMapping.Buckets == nil || len(currentMapping.Buckets) == 0 {
currentMapping.Buckets = n.Defaults.Buckets
}
if currentMapping.Quantiles == nil || len(currentMapping.Quantiles) == 0 {
currentMapping.Quantiles = n.Defaults.Quantiles
}
if currentMapping.Ttl == 0 && n.Defaults.Ttl > 0 {
currentMapping.Ttl = n.Defaults.Ttl
}
}
m.mutex.Lock()
defer m.mutex.Unlock()
m.Defaults = n.Defaults
m.Mappings = n.Mappings
m.InitCache(cacheSize)
if n.doFSM {
var mappings []string
for _, mapping := range n.Mappings {
if mapping.MatchType == MatchTypeGlob {
mappings = append(mappings, mapping.Match)
}
}
n.FSM.BacktrackingNeeded = fsm.TestIfNeedBacktracking(mappings, n.FSM.OrderingDisabled)
m.FSM = n.FSM
m.doRegex = n.doRegex
}
m.doFSM = n.doFSM
if m.MappingsCount != nil {
m.MappingsCount.Set(float64(len(n.Mappings)))
}
return nil
}
func (m *MetricMapper) InitFromFile(fileName string, cacheSize int) error {
mappingStr, err := ioutil.ReadFile(fileName)
if err != nil {
return err
}
return m.InitFromYAMLString(string(mappingStr), cacheSize)
}
func (m *MetricMapper) InitCache(cacheSize int) {
if cacheSize == 0 {
m.cache = NewMetricMapperNoopCache()
} else {
cache, err := NewMetricMapperCache(cacheSize)
if err != nil {
log.Fatalf("Unable to setup metric cache. Caused by: %s", err)
}
m.cache = cache
}
}
func (m *MetricMapper) GetMapping(statsdMetric string, statsdMetricType MetricType) (*MetricMapping, prometheus.Labels, bool) {
m.mutex.RLock()
defer m.mutex.RUnlock()
result, cached := m.cache.Get(statsdMetric, statsdMetricType)
if cached {
return result.Mapping, result.Labels, result.Matched
}
// glob matching
if m.doFSM {
finalState, captures := m.FSM.GetMapping(statsdMetric, string(statsdMetricType))
if finalState != nil && finalState.Result != nil {
result := finalState.Result.(*MetricMapping)
result.Name = result.nameFormatter.Format(captures)
labels := prometheus.Labels{}
for index, formatter := range result.labelFormatters {
labels[result.labelKeys[index]] = formatter.Format(captures)
}
m.cache.AddMatch(statsdMetric, statsdMetricType, result, labels)
return result, labels, true
} else if !m.doRegex {
// if there's no regex match type, return immediately
m.cache.AddMiss(statsdMetric, statsdMetricType)
return nil, nil, false
}
}
// regex matching
for _, mapping := range m.Mappings {
// if a rule don't have regex matching type, the regex field is unset
if mapping.regex == nil {
continue
}
matches := mapping.regex.FindStringSubmatchIndex(statsdMetric)
if len(matches) == 0 {
continue
}
mapping.Name = string(mapping.regex.ExpandString(
[]byte{},
mapping.Name,
statsdMetric,
matches,
))
if mt := mapping.MatchMetricType; mt != "" && mt != statsdMetricType {
continue
}
labels := prometheus.Labels{}
for label, valueExpr := range mapping.Labels {
value := mapping.regex.ExpandString([]byte{}, valueExpr, statsdMetric, matches)
labels[label] = string(value)
}
m.cache.AddMatch(statsdMetric, statsdMetricType, &mapping, labels)
return &mapping, labels, true
}
m.cache.AddMiss(statsdMetric, statsdMetricType)
return nil, nil, false
}