prometheus/rules/ast/query_analyzer.go

212 lines
6.6 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 ast
import (
"time"
clientmodel "github.com/prometheus/client_golang/model"
"github.com/prometheus/prometheus/stats"
"github.com/prometheus/prometheus/storage/local"
)
// FullRangeMap maps the fingerprint of a full range to the duration
// of the matrix selector it resulted from.
type FullRangeMap map[clientmodel.Fingerprint]time.Duration
// IntervalRangeMap is a set of fingerprints of interval ranges.
type IntervalRangeMap map[clientmodel.Fingerprint]bool
// A QueryAnalyzer recursively traverses the AST to look for any nodes
// which will need data from the datastore. Instantiate with
// NewQueryAnalyzer.
type QueryAnalyzer struct {
// Values collected by query analysis.
//
// Full ranges always implicitly span a time range of:
// - start: query interval start - duration
// - end: query interval end
//
// This is because full ranges can only result from matrix selectors (like
// "foo[5m]"), which have said time-spanning behavior during a ranged query.
FullRanges FullRangeMap
// Interval ranges always implicitly span the whole query range.
IntervalRanges IntervalRangeMap
// The underlying storage to which the query will be applied. Needed for
// extracting timeseries fingerprint information during query analysis.
storage local.Storage
}
// NewQueryAnalyzer returns a pointer to a newly instantiated
// QueryAnalyzer. The storage is needed to extract timeseries
// fingerprint information during query analysis.
func NewQueryAnalyzer(storage local.Storage) *QueryAnalyzer {
return &QueryAnalyzer{
FullRanges: FullRangeMap{},
IntervalRanges: IntervalRangeMap{},
storage: storage,
}
}
// Visit implements the Visitor interface.
func (analyzer *QueryAnalyzer) Visit(node Node) {
switch n := node.(type) {
case *VectorSelector:
fingerprints := analyzer.storage.GetFingerprintsForLabelMatchers(n.labelMatchers)
n.fingerprints = fingerprints
for _, fp := range fingerprints {
// Only add the fingerprint to IntervalRanges if not yet present in FullRanges.
// Full ranges always contain more points and span more time than interval ranges.
if _, alreadyInFullRanges := analyzer.FullRanges[fp]; !alreadyInFullRanges {
analyzer.IntervalRanges[fp] = true
}
n.metrics[fp] = analyzer.storage.GetMetricForFingerprint(fp)
}
case *MatrixSelector:
fingerprints := analyzer.storage.GetFingerprintsForLabelMatchers(n.labelMatchers)
n.fingerprints = fingerprints
for _, fp := range fingerprints {
if analyzer.FullRanges[fp] < n.interval {
analyzer.FullRanges[fp] = n.interval
// Delete the fingerprint from IntervalRanges. Full ranges always contain
// more points and span more time than interval ranges, so we don't need
// an interval range for the same fingerprint, should we have one.
delete(analyzer.IntervalRanges, fp)
}
n.metrics[fp] = analyzer.storage.GetMetricForFingerprint(fp)
}
}
}
type iteratorInitializer struct {
storage local.Storage
}
func (i *iteratorInitializer) Visit(node Node) {
switch n := node.(type) {
case *VectorSelector:
for _, fp := range n.fingerprints {
n.iterators[fp] = i.storage.NewIterator(fp)
}
case *MatrixSelector:
for _, fp := range n.fingerprints {
n.iterators[fp] = i.storage.NewIterator(fp)
}
}
}
func prepareInstantQuery(node Node, timestamp clientmodel.Timestamp, storage local.Storage, queryStats *stats.TimerGroup) (local.Preloader, error) {
totalTimer := queryStats.GetTimer(stats.TotalEvalTime)
analyzeTimer := queryStats.GetTimer(stats.QueryAnalysisTime).Start()
analyzer := NewQueryAnalyzer(storage)
Walk(analyzer, node)
analyzeTimer.Stop()
preloadTimer := queryStats.GetTimer(stats.PreloadTime).Start()
p := storage.NewPreloader()
for fp, rangeDuration := range analyzer.FullRanges {
if et := totalTimer.ElapsedTime(); et > *queryTimeout {
preloadTimer.Stop()
p.Close()
return nil, queryTimeoutError{et}
}
if err := p.PreloadRange(fp, timestamp.Add(-rangeDuration), timestamp, *stalenessDelta); err != nil {
preloadTimer.Stop()
p.Close()
return nil, err
}
}
for fp := range analyzer.IntervalRanges {
if et := totalTimer.ElapsedTime(); et > *queryTimeout {
preloadTimer.Stop()
p.Close()
return nil, queryTimeoutError{et}
}
if err := p.PreloadRange(fp, timestamp, timestamp, *stalenessDelta); err != nil {
preloadTimer.Stop()
p.Close()
return nil, err
}
}
preloadTimer.Stop()
ii := &iteratorInitializer{
storage: storage,
}
Walk(ii, node)
return p, nil
}
func prepareRangeQuery(node Node, start clientmodel.Timestamp, end clientmodel.Timestamp, interval time.Duration, storage local.Storage, queryStats *stats.TimerGroup) (local.Preloader, error) {
totalTimer := queryStats.GetTimer(stats.TotalEvalTime)
analyzeTimer := queryStats.GetTimer(stats.QueryAnalysisTime).Start()
analyzer := NewQueryAnalyzer(storage)
Walk(analyzer, node)
analyzeTimer.Stop()
preloadTimer := queryStats.GetTimer(stats.PreloadTime).Start()
p := storage.NewPreloader()
for fp, rangeDuration := range analyzer.FullRanges {
if et := totalTimer.ElapsedTime(); et > *queryTimeout {
preloadTimer.Stop()
p.Close()
return nil, queryTimeoutError{et}
}
if err := p.PreloadRange(fp, start.Add(-rangeDuration), end, *stalenessDelta); err != nil {
preloadTimer.Stop()
p.Close()
return nil, err
}
/*
if interval < rangeDuration {
if err := p.GetMetricRange(fp, end, end.Sub(start)+rangeDuration); err != nil {
p.Close()
return nil, err
}
} else {
if err := p.GetMetricRangeAtInterval(fp, start, end, interval, rangeDuration); err != nil {
p.Close()
return nil, err
}
}
*/
}
for fp := range analyzer.IntervalRanges {
if et := totalTimer.ElapsedTime(); et > *queryTimeout {
preloadTimer.Stop()
p.Close()
return nil, queryTimeoutError{et}
}
if err := p.PreloadRange(fp, start, end, *stalenessDelta); err != nil {
preloadTimer.Stop()
p.Close()
return nil, err
}
}
preloadTimer.Stop()
ii := &iteratorInitializer{
storage: storage,
}
Walk(ii, node)
return p, nil
}