prometheus/promql/test.go
Callum Styan 289ba11b79
Add circular in-memory exemplars storage (#6635)
* Add circular in-memory exemplars storage

Signed-off-by: Callum Styan <callumstyan@gmail.com>
Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
Signed-off-by: Martin Disibio <mdisibio@gmail.com>

Co-authored-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
Co-authored-by: Tom Wilkie <tom.wilkie@gmail.com>
Co-authored-by: Martin Disibio <mdisibio@gmail.com>

* Fix some comments, clean up exemplar metrics struct and exemplar tests.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

* Fix exemplar query api null vs empty array issue.

Signed-off-by: Callum Styan <callumstyan@gmail.com>

Co-authored-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
Co-authored-by: Tom Wilkie <tom.wilkie@gmail.com>
Co-authored-by: Martin Disibio <mdisibio@gmail.com>
2021-03-16 15:17:45 +05:30

793 lines
20 KiB
Go

// Copyright 2015 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 promql
import (
"context"
"fmt"
"io/ioutil"
"math"
"regexp"
"strconv"
"strings"
"time"
"github.com/pkg/errors"
"github.com/prometheus/common/model"
"github.com/prometheus/prometheus/pkg/labels"
"github.com/prometheus/prometheus/pkg/timestamp"
"github.com/prometheus/prometheus/promql/parser"
"github.com/prometheus/prometheus/storage"
"github.com/prometheus/prometheus/tsdb"
"github.com/prometheus/prometheus/util/teststorage"
"github.com/prometheus/prometheus/util/testutil"
)
var (
minNormal = math.Float64frombits(0x0010000000000000) // The smallest positive normal value of type float64.
patSpace = regexp.MustCompile("[\t ]+")
patLoad = regexp.MustCompile(`^load\s+(.+?)$`)
patEvalInstant = regexp.MustCompile(`^eval(?:_(fail|ordered))?\s+instant\s+(?:at\s+(.+?))?\s+(.+)$`)
)
const (
epsilon = 0.000001 // Relative error allowed for sample values.
)
var testStartTime = time.Unix(0, 0).UTC()
// Test is a sequence of read and write commands that are run
// against a test storage.
type Test struct {
testutil.T
cmds []testCommand
storage *teststorage.TestStorage
queryEngine *Engine
context context.Context
cancelCtx context.CancelFunc
}
// NewTest returns an initialized empty Test.
func NewTest(t testutil.T, input string) (*Test, error) {
test := &Test{
T: t,
cmds: []testCommand{},
}
err := test.parse(input)
test.clear()
return test, err
}
func newTestFromFile(t testutil.T, filename string) (*Test, error) {
content, err := ioutil.ReadFile(filename)
if err != nil {
return nil, err
}
return NewTest(t, string(content))
}
// QueryEngine returns the test's query engine.
func (t *Test) QueryEngine() *Engine {
return t.queryEngine
}
// Queryable allows querying the test data.
func (t *Test) Queryable() storage.Queryable {
return t.storage
}
// Context returns the test's context.
func (t *Test) Context() context.Context {
return t.context
}
// Storage returns the test's storage.
func (t *Test) Storage() storage.Storage {
return t.storage
}
// TSDB returns test's TSDB.
func (t *Test) TSDB() *tsdb.DB {
return t.storage.DB
}
// ExemplarStorage returns the test's exemplar storage.
func (t *Test) ExemplarStorage() storage.ExemplarStorage {
return t.storage
}
func (t *Test) ExemplarQueryable() storage.ExemplarQueryable {
return t.storage.ExemplarQueryable()
}
func raise(line int, format string, v ...interface{}) error {
return &parser.ParseErr{
LineOffset: line,
Err: errors.Errorf(format, v...),
}
}
func parseLoad(lines []string, i int) (int, *loadCmd, error) {
if !patLoad.MatchString(lines[i]) {
return i, nil, raise(i, "invalid load command. (load <step:duration>)")
}
parts := patLoad.FindStringSubmatch(lines[i])
gap, err := model.ParseDuration(parts[1])
if err != nil {
return i, nil, raise(i, "invalid step definition %q: %s", parts[1], err)
}
cmd := newLoadCmd(time.Duration(gap))
for i+1 < len(lines) {
i++
defLine := lines[i]
if len(defLine) == 0 {
i--
break
}
metric, vals, err := parser.ParseSeriesDesc(defLine)
if err != nil {
if perr, ok := err.(*parser.ParseErr); ok {
perr.LineOffset = i
}
return i, nil, err
}
cmd.set(metric, vals...)
}
return i, cmd, nil
}
func (t *Test) parseEval(lines []string, i int) (int, *evalCmd, error) {
if !patEvalInstant.MatchString(lines[i]) {
return i, nil, raise(i, "invalid evaluation command. (eval[_fail|_ordered] instant [at <offset:duration>] <query>")
}
parts := patEvalInstant.FindStringSubmatch(lines[i])
var (
mod = parts[1]
at = parts[2]
expr = parts[3]
)
_, err := parser.ParseExpr(expr)
if err != nil {
if perr, ok := err.(*parser.ParseErr); ok {
perr.LineOffset = i
posOffset := parser.Pos(strings.Index(lines[i], expr))
perr.PositionRange.Start += posOffset
perr.PositionRange.End += posOffset
perr.Query = lines[i]
}
return i, nil, err
}
offset, err := model.ParseDuration(at)
if err != nil {
return i, nil, raise(i, "invalid step definition %q: %s", parts[1], err)
}
ts := testStartTime.Add(time.Duration(offset))
cmd := newEvalCmd(expr, ts, i+1)
switch mod {
case "ordered":
cmd.ordered = true
case "fail":
cmd.fail = true
}
for j := 1; i+1 < len(lines); j++ {
i++
defLine := lines[i]
if len(defLine) == 0 {
i--
break
}
if f, err := parseNumber(defLine); err == nil {
cmd.expect(0, nil, parser.SequenceValue{Value: f})
break
}
metric, vals, err := parser.ParseSeriesDesc(defLine)
if err != nil {
if perr, ok := err.(*parser.ParseErr); ok {
perr.LineOffset = i
}
return i, nil, err
}
// Currently, we are not expecting any matrices.
if len(vals) > 1 {
return i, nil, raise(i, "expecting multiple values in instant evaluation not allowed")
}
cmd.expect(j, metric, vals...)
}
return i, cmd, nil
}
// getLines returns trimmed lines after removing the comments.
func getLines(input string) []string {
lines := strings.Split(input, "\n")
for i, l := range lines {
l = strings.TrimSpace(l)
if strings.HasPrefix(l, "#") {
l = ""
}
lines[i] = l
}
return lines
}
// parse the given command sequence and appends it to the test.
func (t *Test) parse(input string) error {
lines := getLines(input)
var err error
// Scan for steps line by line.
for i := 0; i < len(lines); i++ {
l := lines[i]
if len(l) == 0 {
continue
}
var cmd testCommand
switch c := strings.ToLower(patSpace.Split(l, 2)[0]); {
case c == "clear":
cmd = &clearCmd{}
case c == "load":
i, cmd, err = parseLoad(lines, i)
case strings.HasPrefix(c, "eval"):
i, cmd, err = t.parseEval(lines, i)
default:
return raise(i, "invalid command %q", l)
}
if err != nil {
return err
}
t.cmds = append(t.cmds, cmd)
}
return nil
}
// testCommand is an interface that ensures that only the package internal
// types can be a valid command for a test.
type testCommand interface {
testCmd()
}
func (*clearCmd) testCmd() {}
func (*loadCmd) testCmd() {}
func (*evalCmd) testCmd() {}
// loadCmd is a command that loads sequences of sample values for specific
// metrics into the storage.
type loadCmd struct {
gap time.Duration
metrics map[uint64]labels.Labels
defs map[uint64][]Point
}
func newLoadCmd(gap time.Duration) *loadCmd {
return &loadCmd{
gap: gap,
metrics: map[uint64]labels.Labels{},
defs: map[uint64][]Point{},
}
}
func (cmd loadCmd) String() string {
return "load"
}
// set a sequence of sample values for the given metric.
func (cmd *loadCmd) set(m labels.Labels, vals ...parser.SequenceValue) {
h := m.Hash()
samples := make([]Point, 0, len(vals))
ts := testStartTime
for _, v := range vals {
if !v.Omitted {
samples = append(samples, Point{
T: ts.UnixNano() / int64(time.Millisecond/time.Nanosecond),
V: v.Value,
})
}
ts = ts.Add(cmd.gap)
}
cmd.defs[h] = samples
cmd.metrics[h] = m
}
// append the defined time series to the storage.
func (cmd *loadCmd) append(a storage.Appender) error {
for h, smpls := range cmd.defs {
m := cmd.metrics[h]
for _, s := range smpls {
if _, err := a.Append(0, m, s.T, s.V); err != nil {
return err
}
}
}
return nil
}
// evalCmd is a command that evaluates an expression for the given time (range)
// and expects a specific result.
type evalCmd struct {
expr string
start time.Time
line int
fail, ordered bool
metrics map[uint64]labels.Labels
expected map[uint64]entry
}
type entry struct {
pos int
vals []parser.SequenceValue
}
func (e entry) String() string {
return fmt.Sprintf("%d: %s", e.pos, e.vals)
}
func newEvalCmd(expr string, start time.Time, line int) *evalCmd {
return &evalCmd{
expr: expr,
start: start,
line: line,
metrics: map[uint64]labels.Labels{},
expected: map[uint64]entry{},
}
}
func (ev *evalCmd) String() string {
return "eval"
}
// expect adds a new metric with a sequence of values to the set of expected
// results for the query.
func (ev *evalCmd) expect(pos int, m labels.Labels, vals ...parser.SequenceValue) {
if m == nil {
ev.expected[0] = entry{pos: pos, vals: vals}
return
}
h := m.Hash()
ev.metrics[h] = m
ev.expected[h] = entry{pos: pos, vals: vals}
}
// compareResult compares the result value with the defined expectation.
func (ev *evalCmd) compareResult(result parser.Value) error {
switch val := result.(type) {
case Matrix:
return errors.New("received range result on instant evaluation")
case Vector:
seen := map[uint64]bool{}
for pos, v := range val {
fp := v.Metric.Hash()
if _, ok := ev.metrics[fp]; !ok {
return errors.Errorf("unexpected metric %s in result", v.Metric)
}
exp := ev.expected[fp]
if ev.ordered && exp.pos != pos+1 {
return errors.Errorf("expected metric %s with %v at position %d but was at %d", v.Metric, exp.vals, exp.pos, pos+1)
}
if !almostEqual(exp.vals[0].Value, v.V) {
return errors.Errorf("expected %v for %s but got %v", exp.vals[0].Value, v.Metric, v.V)
}
seen[fp] = true
}
for fp, expVals := range ev.expected {
if !seen[fp] {
fmt.Println("vector result", len(val), ev.expr)
for _, ss := range val {
fmt.Println(" ", ss.Metric, ss.Point)
}
return errors.Errorf("expected metric %s with %v not found", ev.metrics[fp], expVals)
}
}
case Scalar:
if !almostEqual(ev.expected[0].vals[0].Value, val.V) {
return errors.Errorf("expected Scalar %v but got %v", val.V, ev.expected[0].vals[0].Value)
}
default:
panic(errors.Errorf("promql.Test.compareResult: unexpected result type %T", result))
}
return nil
}
// clearCmd is a command that wipes the test's storage state.
type clearCmd struct{}
func (cmd clearCmd) String() string {
return "clear"
}
// Run executes the command sequence of the test. Until the maximum error number
// is reached, evaluation errors do not terminate execution.
func (t *Test) Run() error {
for _, cmd := range t.cmds {
// TODO(fabxc): aggregate command errors, yield diffs for result
// comparison errors.
if err := t.exec(cmd); err != nil {
return err
}
}
return nil
}
type atModifierTestCase struct {
expr string
evalTime time.Time
}
func atModifierTestCases(exprStr string, evalTime time.Time) ([]atModifierTestCase, error) {
expr, err := parser.ParseExpr(exprStr)
if err != nil {
return nil, err
}
ts := timestamp.FromTime(evalTime)
containsNonStepInvariant := false
// Setting the @ timestamp for all selectors to be evalTime.
// If there is a subquery, then the selectors inside it don't get the @ timestamp.
// If any selector already has the @ timestamp set, then it is untouched.
parser.Inspect(expr, func(node parser.Node, path []parser.Node) error {
_, _, subqTs := subqueryTimes(path)
if subqTs != nil {
// There is a subquery with timestamp in the path,
// hence don't change any timestamps further.
return nil
}
switch n := node.(type) {
case *parser.VectorSelector:
if n.Timestamp == nil {
n.Timestamp = makeInt64Pointer(ts)
}
case *parser.MatrixSelector:
if vs := n.VectorSelector.(*parser.VectorSelector); vs.Timestamp == nil {
vs.Timestamp = makeInt64Pointer(ts)
}
case *parser.SubqueryExpr:
if n.Timestamp == nil {
n.Timestamp = makeInt64Pointer(ts)
}
case *parser.Call:
_, ok := AtModifierUnsafeFunctions[n.Func.Name]
containsNonStepInvariant = containsNonStepInvariant || ok
}
return nil
})
if containsNonStepInvariant {
// Since there is a step invariant function, we cannot automatically
// generate step invariant test cases for it sanely.
return nil, nil
}
newExpr := expr.String() // With all the @ evalTime set.
additionalEvalTimes := []int64{-10 * ts, 0, ts / 5, ts, 10 * ts}
if ts == 0 {
additionalEvalTimes = []int64{-1000, -ts, 1000}
}
testCases := make([]atModifierTestCase, 0, len(additionalEvalTimes))
for _, et := range additionalEvalTimes {
testCases = append(testCases, atModifierTestCase{
expr: newExpr,
evalTime: timestamp.Time(et),
})
}
return testCases, nil
}
// exec processes a single step of the test.
func (t *Test) exec(tc testCommand) error {
switch cmd := tc.(type) {
case *clearCmd:
t.clear()
case *loadCmd:
app := t.storage.Appender(t.context)
if err := cmd.append(app); err != nil {
app.Rollback()
return err
}
if err := app.Commit(); err != nil {
return err
}
case *evalCmd:
queries, err := atModifierTestCases(cmd.expr, cmd.start)
if err != nil {
return err
}
queries = append([]atModifierTestCase{{expr: cmd.expr, evalTime: cmd.start}}, queries...)
for _, iq := range queries {
q, err := t.QueryEngine().NewInstantQuery(t.storage, iq.expr, iq.evalTime)
if err != nil {
return err
}
defer q.Close()
res := q.Exec(t.context)
if res.Err != nil {
if cmd.fail {
continue
}
return errors.Wrapf(res.Err, "error evaluating query %q (line %d)", iq.expr, cmd.line)
}
if res.Err == nil && cmd.fail {
return errors.Errorf("expected error evaluating query %q (line %d) but got none", iq.expr, cmd.line)
}
err = cmd.compareResult(res.Value)
if err != nil {
return errors.Wrapf(err, "error in %s %s", cmd, iq.expr)
}
// Check query returns same result in range mode,
// by checking against the middle step.
q, err = t.queryEngine.NewRangeQuery(t.storage, iq.expr, iq.evalTime.Add(-time.Minute), iq.evalTime.Add(time.Minute), time.Minute)
if err != nil {
return err
}
rangeRes := q.Exec(t.context)
if rangeRes.Err != nil {
return errors.Wrapf(rangeRes.Err, "error evaluating query %q (line %d) in range mode", iq.expr, cmd.line)
}
defer q.Close()
if cmd.ordered {
// Ordering isn't defined for range queries.
continue
}
mat := rangeRes.Value.(Matrix)
vec := make(Vector, 0, len(mat))
for _, series := range mat {
for _, point := range series.Points {
if point.T == timeMilliseconds(iq.evalTime) {
vec = append(vec, Sample{Metric: series.Metric, Point: point})
break
}
}
}
if _, ok := res.Value.(Scalar); ok {
err = cmd.compareResult(Scalar{V: vec[0].Point.V})
} else {
err = cmd.compareResult(vec)
}
if err != nil {
return errors.Wrapf(err, "error in %s %s (line %d) rande mode", cmd, iq.expr, cmd.line)
}
}
default:
panic("promql.Test.exec: unknown test command type")
}
return nil
}
// clear the current test storage of all inserted samples.
func (t *Test) clear() {
if t.storage != nil {
if err := t.storage.Close(); err != nil {
t.T.Fatalf("closing test storage: %s", err)
}
}
if t.cancelCtx != nil {
t.cancelCtx()
}
t.storage = teststorage.New(t)
opts := EngineOpts{
Logger: nil,
Reg: nil,
MaxSamples: 10000,
Timeout: 100 * time.Second,
NoStepSubqueryIntervalFn: func(int64) int64 { return durationMilliseconds(1 * time.Minute) },
EnableAtModifier: true,
}
t.queryEngine = NewEngine(opts)
t.context, t.cancelCtx = context.WithCancel(context.Background())
}
// Close closes resources associated with the Test.
func (t *Test) Close() {
t.cancelCtx()
if err := t.storage.Close(); err != nil {
t.T.Fatalf("closing test storage: %s", err)
}
}
// samplesAlmostEqual returns true if the two sample lines only differ by a
// small relative error in their sample value.
func almostEqual(a, b float64) bool {
// NaN has no equality but for testing we still want to know whether both values
// are NaN.
if math.IsNaN(a) && math.IsNaN(b) {
return true
}
// Cf. http://floating-point-gui.de/errors/comparison/
if a == b {
return true
}
diff := math.Abs(a - b)
if a == 0 || b == 0 || diff < minNormal {
return diff < epsilon*minNormal
}
return diff/(math.Abs(a)+math.Abs(b)) < epsilon
}
func parseNumber(s string) (float64, error) {
n, err := strconv.ParseInt(s, 0, 64)
f := float64(n)
if err != nil {
f, err = strconv.ParseFloat(s, 64)
}
if err != nil {
return 0, errors.Wrap(err, "error parsing number")
}
return f, nil
}
// LazyLoader lazily loads samples into storage.
// This is specifically implemented for unit testing of rules.
type LazyLoader struct {
testutil.T
loadCmd *loadCmd
storage storage.Storage
SubqueryInterval time.Duration
queryEngine *Engine
context context.Context
cancelCtx context.CancelFunc
}
// NewLazyLoader returns an initialized empty LazyLoader.
func NewLazyLoader(t testutil.T, input string) (*LazyLoader, error) {
ll := &LazyLoader{
T: t,
}
err := ll.parse(input)
ll.clear()
return ll, err
}
// parse the given load command.
func (ll *LazyLoader) parse(input string) error {
lines := getLines(input)
// Accepts only 'load' command.
for i := 0; i < len(lines); i++ {
l := lines[i]
if len(l) == 0 {
continue
}
if strings.ToLower(patSpace.Split(l, 2)[0]) == "load" {
_, cmd, err := parseLoad(lines, i)
if err != nil {
return err
}
ll.loadCmd = cmd
return nil
}
return raise(i, "invalid command %q", l)
}
return errors.New("no \"load\" command found")
}
// clear the current test storage of all inserted samples.
func (ll *LazyLoader) clear() {
if ll.storage != nil {
if err := ll.storage.Close(); err != nil {
ll.T.Fatalf("closing test storage: %s", err)
}
}
if ll.cancelCtx != nil {
ll.cancelCtx()
}
ll.storage = teststorage.New(ll)
opts := EngineOpts{
Logger: nil,
Reg: nil,
MaxSamples: 10000,
Timeout: 100 * time.Second,
NoStepSubqueryIntervalFn: func(int64) int64 { return durationMilliseconds(ll.SubqueryInterval) },
EnableAtModifier: true,
}
ll.queryEngine = NewEngine(opts)
ll.context, ll.cancelCtx = context.WithCancel(context.Background())
}
// appendTill appends the defined time series to the storage till the given timestamp (in milliseconds).
func (ll *LazyLoader) appendTill(ts int64) error {
app := ll.storage.Appender(ll.Context())
for h, smpls := range ll.loadCmd.defs {
m := ll.loadCmd.metrics[h]
for i, s := range smpls {
if s.T > ts {
// Removing the already added samples.
ll.loadCmd.defs[h] = smpls[i:]
break
}
if _, err := app.Append(0, m, s.T, s.V); err != nil {
return err
}
if i == len(smpls)-1 {
ll.loadCmd.defs[h] = nil
}
}
}
return app.Commit()
}
// WithSamplesTill loads the samples till given timestamp and executes the given function.
func (ll *LazyLoader) WithSamplesTill(ts time.Time, fn func(error)) {
tsMilli := ts.Sub(time.Unix(0, 0).UTC()) / time.Millisecond
fn(ll.appendTill(int64(tsMilli)))
}
// QueryEngine returns the LazyLoader's query engine.
func (ll *LazyLoader) QueryEngine() *Engine {
return ll.queryEngine
}
// Queryable allows querying the LazyLoader's data.
// Note: only the samples till the max timestamp used
// in `WithSamplesTill` can be queried.
func (ll *LazyLoader) Queryable() storage.Queryable {
return ll.storage
}
// Context returns the LazyLoader's context.
func (ll *LazyLoader) Context() context.Context {
return ll.context
}
// Storage returns the LazyLoader's storage.
func (ll *LazyLoader) Storage() storage.Storage {
return ll.storage
}
// Close closes resources associated with the LazyLoader.
func (ll *LazyLoader) Close() {
ll.cancelCtx()
if err := ll.storage.Close(); err != nil {
ll.T.Fatalf("closing test storage: %s", err)
}
}