Marek Siarkowicz c2655b4112 Fix watch validation assuming that client requesting older watch revision
Signed-off-by: Marek Siarkowicz <siarkowicz@google.com>
2023-10-05 14:09:43 +02:00

224 lines
8.0 KiB
Go

// Copyright 2023 The etcd 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 validate
import (
"sort"
"testing"
"github.com/google/go-cmp/cmp"
"go.etcd.io/etcd/tests/v3/robustness/model"
"go.etcd.io/etcd/tests/v3/robustness/report"
)
func validateWatch(t *testing.T, cfg Config, reports []report.ClientReport) []model.WatchEvent {
// Validate etcd watch properties defined in https://etcd.io/docs/v3.6/learning/api_guarantees/#watch-apis
for _, r := range reports {
validateOrdered(t, r)
validateUnique(t, cfg.ExpectRevisionUnique, r)
validateAtomic(t, r)
validateBookmarkable(t, r)
}
// TODO: Use linearization result instead of event history to get order of events
// This is currently impossible as porcupine doesn't expose operation order created during linearization.
eventHistory := mergeWatchEventHistory(t, reports)
for _, r := range reports {
validateReliable(t, eventHistory, r)
validateResumable(t, eventHistory, r)
}
return eventHistory
}
func validateBookmarkable(t *testing.T, report report.ClientReport) {
for _, op := range report.Watch {
var lastProgressNotifyRevision int64
for _, resp := range op.Responses {
for _, event := range resp.Events {
if event.Revision <= lastProgressNotifyRevision {
t.Errorf("Broke watch guarantee: Bookmarkable - Progress notification events guarantee that all events up to a revision have been already delivered, eventRevision: %d, progressNotifyRevision: %d", event.Revision, lastProgressNotifyRevision)
}
}
if resp.IsProgressNotify {
lastProgressNotifyRevision = resp.Revision
}
}
}
}
func validateOrdered(t *testing.T, report report.ClientReport) {
for _, op := range report.Watch {
var lastEventRevision int64 = 1
for _, resp := range op.Responses {
for _, event := range resp.Events {
if event.Revision < lastEventRevision {
t.Errorf("Broke watch guarantee: Ordered - events are ordered by revision; an event will never appear on a watch if it precedes an event in time that has already been posted, lastRevision: %d, currentRevision: %d, client: %d", lastEventRevision, event.Revision, report.ClientId)
}
lastEventRevision = event.Revision
}
}
}
}
func validateUnique(t *testing.T, expectUniqueRevision bool, report report.ClientReport) {
for _, op := range report.Watch {
uniqueOperations := map[any]struct{}{}
for _, resp := range op.Responses {
for _, event := range resp.Events {
var key any
if expectUniqueRevision {
key = event.Revision
} else {
key = struct {
revision int64
key string
}{event.Revision, event.Key}
}
if _, found := uniqueOperations[key]; found {
t.Errorf("Broke watch guarantee: Unique - an event will never appear on a watch twice, key: %q, revision: %d, client: %d", event.Key, event.Revision, report.ClientId)
}
uniqueOperations[key] = struct{}{}
}
}
}
}
func validateAtomic(t *testing.T, report report.ClientReport) {
for _, op := range report.Watch {
var lastEventRevision int64 = 1
for _, resp := range op.Responses {
if len(resp.Events) > 0 {
if resp.Events[0].Revision == lastEventRevision {
t.Errorf("Broke watch guarantee: Atomic - a list of events is guaranteed to encompass complete revisions; updates in the same revision over multiple keys will not be split over several lists of events, previousListEventRevision: %d, currentListEventRevision: %d, client: %d", lastEventRevision, resp.Events[0].Revision, report.ClientId)
}
lastEventRevision = resp.Events[len(resp.Events)-1].Revision
}
}
}
}
func validateReliable(t *testing.T, events []model.WatchEvent, report report.ClientReport) {
for _, op := range report.Watch {
index := 0
revision := firstRevision(op)
for index < len(events) && events[index].Revision < revision {
index++
}
if index == len(events) {
continue
}
for _, resp := range op.Responses {
for _, event := range resp.Events {
if events[index].Match(op.Request) && events[index] != event {
t.Errorf("Broke watch guarantee: Reliable - a sequence of events will never drop any subsequence of events; if there are events ordered in time as a < b < c, then if the watch receives events a and c, it is guaranteed to receive b, event missing: %+v", events[index])
}
index++
}
}
}
}
func validateResumable(t *testing.T, events []model.WatchEvent, report report.ClientReport) {
for _, op := range report.Watch {
index := 0
revision := op.Request.Revision
for index < len(events) && (events[index].Revision < revision || !events[index].Match(op.Request)) {
index++
}
if index == len(events) {
continue
}
firstEvent := firstWatchEvent(op)
// If watch is resumable, first event it gets should the first event that happened after the requested revision.
if firstEvent != nil && events[index] != *firstEvent {
t.Errorf("Resumable - A broken watch can be resumed by establishing a new watch starting after the last revision received in a watch event before the break, so long as the revision is in the history window, watch request: %+v, event missing: %+v", op.Request, events[index])
}
}
}
func firstRevision(op model.WatchOperation) int64 {
for _, resp := range op.Responses {
for _, event := range resp.Events {
return event.Revision
}
}
return 0
}
func firstWatchEvent(op model.WatchOperation) *model.WatchEvent {
for _, resp := range op.Responses {
for _, event := range resp.Events {
return &event
}
}
return nil
}
func mergeWatchEventHistory(t *testing.T, reports []report.ClientReport) []model.WatchEvent {
type revisionEvents struct {
events []model.WatchEvent
revision int64
clientId int
}
revisionToEvents := map[int64]revisionEvents{}
var lastClientId = 0
var lastRevision int64
events := []model.WatchEvent{}
for _, r := range reports {
for _, op := range r.Watch {
for _, resp := range op.Responses {
for _, event := range resp.Events {
if event.Revision == lastRevision && lastClientId == r.ClientId {
events = append(events, event)
} else {
if prev, found := revisionToEvents[lastRevision]; found {
// This assumes that there are txn that would be observed differently by two watches.
// TODO: Implement merging events from multiple watches about single revision based on operations.
if diff := cmp.Diff(prev.events, events); diff != "" {
t.Errorf("Events between clients %d and %d don't match, revision: %d, diff: %s", prev.clientId, lastClientId, lastRevision, diff)
}
} else {
revisionToEvents[lastRevision] = revisionEvents{clientId: lastClientId, events: events, revision: lastRevision}
}
lastClientId = r.ClientId
lastRevision = event.Revision
events = []model.WatchEvent{event}
}
}
}
}
}
if prev, found := revisionToEvents[lastRevision]; found {
if diff := cmp.Diff(prev.events, events); diff != "" {
t.Errorf("Events between clients %d and %d don't match, revision: %d, diff: %s", prev.clientId, lastClientId, lastRevision, diff)
}
} else {
revisionToEvents[lastRevision] = revisionEvents{clientId: lastClientId, events: events, revision: lastRevision}
}
var allRevisionEvents []revisionEvents
for _, revEvents := range revisionToEvents {
allRevisionEvents = append(allRevisionEvents, revEvents)
}
sort.Slice(allRevisionEvents, func(i, j int) bool {
return allRevisionEvents[i].revision < allRevisionEvents[j].revision
})
var eventHistory []model.WatchEvent
for _, revEvents := range allRevisionEvents {
eventHistory = append(eventHistory, revEvents.events...)
}
return eventHistory
}