tasks/service/history/nDCStandbyTaskUtil.go

// The MIT License
//
// Copyright (c) 2020 Temporal Technologies Inc.  All rights reserved.
//
// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package history

import (
	"context"
	"errors"
	"time"

	taskqueuepb "go.temporal.io/api/taskqueue/v1"
	taskqueuespb "go.temporal.io/server/api/taskqueue/v1"

	"go.temporal.io/server/common"
	"go.temporal.io/server/common/log"
	"go.temporal.io/server/common/log/tag"
	"go.temporal.io/server/common/namespace"
	"go.temporal.io/server/common/persistence/versionhistory"
	"go.temporal.io/server/service/history/consts"
	"go.temporal.io/server/service/history/tasks"
	"go.temporal.io/server/service/history/workflow"
)

type (
	standbyActionFn     func(context.Context, workflow.Context, workflow.MutableState) (interface{}, error)
	standbyPostActionFn func(context.Context, tasks.Task, interface{}, log.Logger) error

	standbyCurrentTimeFn func() time.Time
)

func standbyTaskPostActionNoOp(
	_ context.Context,
	_ tasks.Task,
	postActionInfo interface{},
	_ log.Logger,
) error {

	if postActionInfo == nil {
		return nil
	}

	// return error so task processing logic will retry
	return consts.ErrTaskRetry
}

func standbyTransferTaskPostActionTaskDiscarded(
	_ context.Context,
	taskInfo tasks.Task,
	postActionInfo interface{},
	logger log.Logger,
) error {

	if postActionInfo == nil {
		return nil
	}

	logger.Warn("Discarding standby transfer task due to task being pending for too long.", tag.Task(taskInfo))
	return consts.ErrTaskDiscarded
}

func standbyTimerTaskPostActionTaskDiscarded(
	_ context.Context,
	taskInfo tasks.Task,
	postActionInfo interface{},
	logger log.Logger,
) error {

	if postActionInfo == nil {
		return nil
	}

	logger.Warn("Discarding standby timer task due to task being pending for too long.", tag.Task(taskInfo))
	return consts.ErrTaskDiscarded
}

type (
	historyResendInfo struct {

		// used by NDC
		lastEventID      int64
		lastEventVersion int64
	}

	activityTaskPostActionInfo struct {
		*historyResendInfo

		taskQueue                          string
		activityTaskScheduleToStartTimeout time.Duration
		versionDirective                   *taskqueuespb.TaskVersionDirective
	}

	workflowTaskPostActionInfo struct {
		*historyResendInfo

		workflowTaskScheduleToStartTimeout *time.Duration
		taskqueue                          taskqueuepb.TaskQueue
		versionDirective                   *taskqueuespb.TaskVersionDirective
	}

	startChildExecutionPostActionInfo struct {
		*historyResendInfo
	}
)

var (
	// verifyChildCompletionRecordedInfo is the post action info returned by
	// standby close execution task action func. The actual content of the
	// struct doesn't matter. We just need a non-nil pointer to to indicate
	// that the verification has failed.
	verifyChildCompletionRecordedInfo = &struct{}{}
)

func newHistoryResendInfo(
	lastEventID int64,
	lastEventVersion int64,
) *historyResendInfo {
	return &historyResendInfo{
		lastEventID:      lastEventID,
		lastEventVersion: lastEventVersion,
	}
}

func newActivityTaskPostActionInfo(
	mutableState workflow.MutableState,
	activityScheduleToStartTimeout time.Duration,
	useCompatibleVersion bool,
) (*activityTaskPostActionInfo, error) {
	resendInfo, err := getHistoryResendInfo(mutableState)
	if err != nil {
		return nil, err
	}

	directive := common.MakeVersionDirectiveForActivityTask(mutableState.GetWorkerVersionStamp(), useCompatibleVersion)

	return &activityTaskPostActionInfo{
		historyResendInfo:                  resendInfo,
		activityTaskScheduleToStartTimeout: activityScheduleToStartTimeout,
		versionDirective:                   directive,
	}, nil
}

func newActivityRetryTimePostActionInfo(
	mutableState workflow.MutableState,
	taskQueue string,
	activityScheduleToStartTimeout time.Duration,
	useCompatibleVersion bool,
) (*activityTaskPostActionInfo, error) {
	resendInfo, err := getHistoryResendInfo(mutableState)
	if err != nil {
		return nil, err
	}

	directive := common.MakeVersionDirectiveForActivityTask(mutableState.GetWorkerVersionStamp(), useCompatibleVersion)

	return &activityTaskPostActionInfo{
		historyResendInfo:                  resendInfo,
		taskQueue:                          taskQueue,
		activityTaskScheduleToStartTimeout: activityScheduleToStartTimeout,
		versionDirective:                   directive,
	}, nil
}

func newWorkflowTaskPostActionInfo(
	mutableState workflow.MutableState,
	workflowTaskScheduleToStartTimeout *time.Duration,
	taskqueue taskqueuepb.TaskQueue,
) (*workflowTaskPostActionInfo, error) {
	resendInfo, err := getHistoryResendInfo(mutableState)
	if err != nil {
		return nil, err
	}

	directive := common.MakeVersionDirectiveForWorkflowTask(
		mutableState.GetWorkerVersionStamp(),
		mutableState.GetLastWorkflowTaskStartedEventID(),
	)

	return &workflowTaskPostActionInfo{
		historyResendInfo:                  resendInfo,
		workflowTaskScheduleToStartTimeout: workflowTaskScheduleToStartTimeout,
		taskqueue:                          taskqueue,
		versionDirective:                   directive,
	}, nil
}

func getHistoryResendInfo(
	mutableState workflow.MutableState,
) (*historyResendInfo, error) {

	currentBranch, err := versionhistory.GetCurrentVersionHistory(mutableState.GetExecutionInfo().GetVersionHistories())
	if err != nil {
		return nil, err
	}
	lastItem, err := versionhistory.GetLastVersionHistoryItem(currentBranch)
	if err != nil {
		return nil, err
	}
	return newHistoryResendInfo(lastItem.GetEventId(), lastItem.GetVersion()), nil
}

func getStandbyPostActionFn(
	taskInfo tasks.Task,
	standbyNow standbyCurrentTimeFn,
	standbyTaskMissingEventsResendDelay time.Duration,
	standbyTaskMissingEventsDiscardDelay time.Duration,
	fetchHistoryStandbyPostActionFn standbyPostActionFn,
	discardTaskStandbyPostActionFn standbyPostActionFn,
) standbyPostActionFn {

	// this is for task retry, use machine time
	now := standbyNow()
	taskTime := taskInfo.GetVisibilityTime()
	resendTime := taskTime.Add(standbyTaskMissingEventsResendDelay)
	discardTime := taskTime.Add(standbyTaskMissingEventsDiscardDelay)

	// now < task start time + StandbyTaskMissingEventsResendDelay
	if now.Before(resendTime) {
		return standbyTaskPostActionNoOp
	}

	// task start time + StandbyTaskMissingEventsResendDelay <= now < task start time + StandbyTaskMissingEventsResendDelay
	if now.Before(discardTime) {
		return fetchHistoryStandbyPostActionFn
	}

	// task start time + StandbyTaskMissingEventsResendDelay <= now
	return discardTaskStandbyPostActionFn
}

func getRemoteClusterName(
	currentCluster string,
	registry namespace.Registry,
	namespaceID string,
) (string, error) {
	namespaceEntry, err := registry.GetNamespaceByID(namespace.ID(namespaceID))
	if err != nil {
		return "", err
	}

	remoteClusterName := namespaceEntry.ActiveClusterName()
	if remoteClusterName == currentCluster {
		// namespace has turned active, retry the task
		return "", errors.New("namespace becomes active when processing task as standby")
	}
	return remoteClusterName, nil
}