Add support for providing custom checkpointer (#17)

* Add credential configuration for resources Add credentials for Kinesis, DynamoDB and Cloudwatch. See the worker_test.go to see how to use it. Signed-off-by: Tao Jiang <taoj@vmware.com> * Add support for providing custom checkpointer Provide a new constructor for adding checkpointer instead of alway using default dynamodb checkpointer. The next step is to abstract out the Kinesis into a generic stream API and this will be bigger change and will be addressed in different PR. Test: Use the new construtor to inject dynamodb checkpointer and run the existing tests. Signed-off-by: Tao Jiang <taoj@vmware.com> * Add support for providing custom checkpointer Provide a new constructor for adding checkpointer instead of alway using default dynamodb checkpointer. The next step is to abstract out the Kinesis into a generic stream API and this will be bigger change and will be addressed in different PR. Fix checkfmt error. Test: Use the new construtor to inject dynamodb checkpointer and run the existing tests. Signed-off-by: Tao Jiang <taoj@vmware.com>
2019-04-22 15:55:39 -05:00 · 2019-04-22 15:55:39 -05:00 · 2ca82c25ca
commit 2ca82c25ca
parent c634c75ebc
11 changed files with 321 additions and 93 deletions
--- a/2
+++ b/2
@ -88,5 +88,5 @@ settings:
  default-targets:
    - ci
  docker:
-    image: 'vmware/go-kcl-toolchain:latest'
+    image: 'vmware/go-kcl-toolchain:0.1.2'
    src-volume: /go/src/github.com/vmware/vmware-go-kcl
--- a/clientlibrary/checkpoint/checkpointer.go
+++ b/clientlibrary/checkpoint/checkpointer.go
@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2018 VMware, 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.
+ */
+// The implementation is derived from https://github.com/patrobinson/gokini
+//
+// Copyright 2018 Patrick robinson
+//
+// 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 checkpoint
+
+import (
+	"errors"
+	par "github.com/vmware/vmware-go-kcl/clientlibrary/partition"
+)
+
+const (
+	LEASE_KEY_KEY                  = "ShardID"
+	LEASE_OWNER_KEY                = "AssignedTo"
+	LEASE_TIMEOUT_KEY              = "LeaseTimeout"
+	CHECKPOINT_SEQUENCE_NUMBER_KEY = "Checkpoint"
+	PARENT_SHARD_ID_KEY            = "ParentShardId"
+
+	// We've completely processed all records in this shard.
+	SHARD_END = "SHARD_END"
+
+	// ErrLeaseNotAquired is returned when we failed to get a lock on the shard
+	ErrLeaseNotAquired = "Lease is already held by another node"
+)
+
+// Checkpointer handles checkpointing when a record has been processed
+type Checkpointer interface {
+	Init() error
+	GetLease(*par.ShardStatus, string) error
+	CheckpointSequence(*par.ShardStatus) error
+	FetchCheckpoint(*par.ShardStatus) error
+	RemoveLeaseInfo(string) error
+}
+
+// ErrSequenceIDNotFound is returned by FetchCheckpoint when no SequenceID is found
+var ErrSequenceIDNotFound = errors.New("SequenceIDNotFoundForShard")
--- a/clientlibrary/checkpoint/dynamodb-checkpointer.go
+++ b/clientlibrary/checkpoint/dynamodb-checkpointer.go
@ -25,7 +25,7 @@
 // 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 worker
+package checkpoint

 import (
 	"errors"
@ -40,36 +40,14 @@ import (
 	log "github.com/sirupsen/logrus"

 	"github.com/vmware/vmware-go-kcl/clientlibrary/config"
+	par "github.com/vmware/vmware-go-kcl/clientlibrary/partition"
 )

 const (
-	LEASE_KEY_KEY                  = "ShardID"
-	LEASE_OWNER_KEY                = "AssignedTo"
-	LEASE_TIMEOUT_KEY              = "LeaseTimeout"
-	CHECKPOINT_SEQUENCE_NUMBER_KEY = "Checkpoint"
-	PARENT_SHARD_ID_KEY            = "ParentShardId"
-
-	// We've completely processed all records in this shard.
-	SHARD_END = "SHARD_END"
-
-	// ErrLeaseNotAquired is returned when we failed to get a lock on the shard
-	ErrLeaseNotAquired = "Lease is already held by another node"
 	// ErrInvalidDynamoDBSchema is returned when there are one or more fields missing from the table
 	ErrInvalidDynamoDBSchema = "The DynamoDB schema is invalid and may need to be re-created"
 )

-// Checkpointer handles checkpointing when a record has been processed
-type Checkpointer interface {
-	Init() error
-	GetLease(*shardStatus, string) error
-	CheckpointSequence(*shardStatus) error
-	FetchCheckpoint(*shardStatus) error
-	RemoveLeaseInfo(string) error
-}
-
-// ErrSequenceIDNotFound is returned by FetchCheckpoint when no SequenceID is found
-var ErrSequenceIDNotFound = errors.New("SequenceIDNotFoundForShard")
-
 // DynamoCheckpoint implements the Checkpoint interface using DynamoDB as a backend
 type DynamoCheckpoint struct {
 	TableName               string
@ -104,7 +82,7 @@ func (checkpointer *DynamoCheckpoint) Init() error {
 }

 // GetLease attempts to gain a lock on the given shard
-func (checkpointer *DynamoCheckpoint) GetLease(shard *shardStatus, newAssignTo string) error {
+func (checkpointer *DynamoCheckpoint) GetLease(shard *par.ShardStatus, newAssignTo string) error {
 	newLeaseTimeout := time.Now().Add(time.Duration(checkpointer.LeaseDuration) * time.Millisecond).UTC()
 	newLeaseTimeoutString := newLeaseTimeout.Format(time.RFC3339)
 	currentCheckpoint, err := checkpointer.getItem(shard.ID)
@ -177,16 +155,16 @@ func (checkpointer *DynamoCheckpoint) GetLease(shard *shardStatus, newAssignTo s
 		return err
 	}

-	shard.mux.Lock()
+	shard.Mux.Lock()
 	shard.AssignedTo = newAssignTo
 	shard.LeaseTimeout = newLeaseTimeout
-	shard.mux.Unlock()
+	shard.Mux.Unlock()

 	return nil
 }

 // CheckpointSequence writes a checkpoint at the designated sequence ID
-func (checkpointer *DynamoCheckpoint) CheckpointSequence(shard *shardStatus) error {
+func (checkpointer *DynamoCheckpoint) CheckpointSequence(shard *par.ShardStatus) error {
 	leaseTimeout := shard.LeaseTimeout.UTC().Format(time.RFC3339)
 	marshalledCheckpoint := map[string]*dynamodb.AttributeValue{
 		LEASE_KEY_KEY: {
@ -211,7 +189,7 @@ func (checkpointer *DynamoCheckpoint) CheckpointSequence(shard *shardStatus) err
 }

 // FetchCheckpoint retrieves the checkpoint for the given shard
-func (checkpointer *DynamoCheckpoint) FetchCheckpoint(shard *shardStatus) error {
+func (checkpointer *DynamoCheckpoint) FetchCheckpoint(shard *par.ShardStatus) error {
 	checkpoint, err := checkpointer.getItem(shard.ID)
 	if err != nil {
 		return err
@ -222,8 +200,8 @@ func (checkpointer *DynamoCheckpoint) FetchCheckpoint(shard *shardStatus) error
 		return ErrSequenceIDNotFound
 	}
 	log.Debugf("Retrieved Shard Iterator %s", *sequenceID.S)
-	shard.mux.Lock()
-	defer shard.mux.Unlock()
+	shard.Mux.Lock()
+	defer shard.Mux.Unlock()
 	shard.Checkpoint = *sequenceID.S

 	if assignedTo, ok := checkpoint[LEASE_OWNER_KEY]; ok {
--- a/clientlibrary/partition/partition.go
+++ b/clientlibrary/partition/partition.go
@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2018 VMware, 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.
+ */
+// The implementation is derived from https://github.com/patrobinson/gokini
+//
+// Copyright 2018 Patrick robinson
+//
+// 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 worker
+
+import (
+	"sync"
+	"time"
+)
+
+type ShardStatus struct {
+	ID            string
+	ParentShardId string
+	Checkpoint    string
+	AssignedTo    string
+	Mux           *sync.Mutex
+	LeaseTimeout  time.Time
+	// Shard Range
+	StartingSequenceNumber string
+	// child shard doesn't have end sequence number
+	EndingSequenceNumber string
+}
+
+func (ss *ShardStatus) GetLeaseOwner() string {
+	ss.Mux.Lock()
+	defer ss.Mux.Unlock()
+	return ss.AssignedTo
+}
+
+func (ss *ShardStatus) SetLeaseOwner(owner string) {
+	ss.Mux.Lock()
+	defer ss.Mux.Unlock()
+	ss.AssignedTo = owner
+}
--- a/clientlibrary/worker/record-processor-checkpointer.go
+++ b/clientlibrary/worker/record-processor-checkpointer.go
@ -21,7 +21,9 @@ package worker
 import (
 	"github.com/aws/aws-sdk-go/aws"

+	chk "github.com/vmware/vmware-go-kcl/clientlibrary/checkpoint"
 	kcl "github.com/vmware/vmware-go-kcl/clientlibrary/interfaces"
+	par "github.com/vmware/vmware-go-kcl/clientlibrary/partition"
 )

 type (
@ -41,12 +43,12 @@ type (
 	 * RecordProcessor instance. Amazon Kinesis Client Library will create one instance per shard assignment.
 	 */
 	RecordProcessorCheckpointer struct {
-		shard      *shardStatus
-		checkpoint Checkpointer
+		shard      *par.ShardStatus
+		checkpoint chk.Checkpointer
 	}
 )

-func NewRecordProcessorCheckpoint(shard *shardStatus, checkpoint Checkpointer) kcl.IRecordProcessorCheckpointer {
+func NewRecordProcessorCheckpoint(shard *par.ShardStatus, checkpoint chk.Checkpointer) kcl.IRecordProcessorCheckpointer {
 	return &RecordProcessorCheckpointer{
 		shard:      shard,
 		checkpoint: checkpoint,
@ -62,16 +64,16 @@ func (pc *PreparedCheckpointer) Checkpoint() error {
 }

 func (rc *RecordProcessorCheckpointer) Checkpoint(sequenceNumber *string) error {
-	rc.shard.mux.Lock()
+	rc.shard.Mux.Lock()

 	// checkpoint the last sequence of a closed shard
 	if sequenceNumber == nil {
-		rc.shard.Checkpoint = SHARD_END
+		rc.shard.Checkpoint = chk.SHARD_END
 	} else {
 		rc.shard.Checkpoint = aws.StringValue(sequenceNumber)
 	}

-	rc.shard.mux.Unlock()
+	rc.shard.Mux.Unlock()
 	return rc.checkpoint.CheckpointSequence(rc.shard)
 }

--- a/clientlibrary/worker/shard-consumer.go
+++ b/clientlibrary/worker/shard-consumer.go
@ -38,9 +38,11 @@ import (
 	"github.com/aws/aws-sdk-go/service/kinesis"
 	"github.com/aws/aws-sdk-go/service/kinesis/kinesisiface"

+	chk "github.com/vmware/vmware-go-kcl/clientlibrary/checkpoint"
 	"github.com/vmware/vmware-go-kcl/clientlibrary/config"
 	kcl "github.com/vmware/vmware-go-kcl/clientlibrary/interfaces"
 	"github.com/vmware/vmware-go-kcl/clientlibrary/metrics"
+	par "github.com/vmware/vmware-go-kcl/clientlibrary/partition"
 )

 const (
@ -71,9 +73,9 @@ type ShardConsumerState int
 // Note: ShardConsumer only deal with one shard.
 type ShardConsumer struct {
 	streamName      string
-	shard           *shardStatus
+	shard           *par.ShardStatus
 	kc              kinesisiface.KinesisAPI
-	checkpointer    Checkpointer
+	checkpointer    chk.Checkpointer
 	recordProcessor kcl.IRecordProcessor
 	kclConfig       *config.KinesisClientLibConfiguration
 	stop            *chan struct{}
@ -83,10 +85,10 @@ type ShardConsumer struct {
 	state           ShardConsumerState
 }

-func (sc *ShardConsumer) getShardIterator(shard *shardStatus) (*string, error) {
+func (sc *ShardConsumer) getShardIterator(shard *par.ShardStatus) (*string, error) {
 	// Get checkpoint of the shard from dynamoDB
 	err := sc.checkpointer.FetchCheckpoint(shard)
-	if err != nil && err != ErrSequenceIDNotFound {
+	if err != nil && err != chk.ErrSequenceIDNotFound {
 		return nil, err
 	}

@ -123,14 +125,14 @@ func (sc *ShardConsumer) getShardIterator(shard *shardStatus) (*string, error) {

 // getRecords continously poll one shard for data record
 // Precondition: it currently has the lease on the shard.
-func (sc *ShardConsumer) getRecords(shard *shardStatus) error {
+func (sc *ShardConsumer) getRecords(shard *par.ShardStatus) error {
 	defer sc.waitGroup.Done()
 	defer sc.releaseLease(shard)

 	// If the shard is child shard, need to wait until the parent finished.
 	if err := sc.waitOnParentShard(shard); err != nil {
 		// If parent shard has been deleted by Kinesis system already, just ignore the error.
-		if err != ErrSequenceIDNotFound {
+		if err != chk.ErrSequenceIDNotFound {
 			log.Errorf("Error in waiting for parent shard: %v to finish. Error: %+v", shard.ParentShardId, err)
 			return err
 		}
@ -158,7 +160,7 @@ func (sc *ShardConsumer) getRecords(shard *shardStatus) error {
 			log.Debugf("Refreshing lease on shard: %s for worker: %s", shard.ID, sc.consumerID)
 			err = sc.checkpointer.GetLease(shard, sc.consumerID)
 			if err != nil {
-				if err.Error() == ErrLeaseNotAquired {
+				if err.Error() == chk.ErrLeaseNotAquired {
 					log.Warnf("Failed in acquiring lease on shard: %s for worker: %s", shard.ID, sc.consumerID)
 					return nil
 				}
@ -255,14 +257,14 @@ func (sc *ShardConsumer) getRecords(shard *shardStatus) error {
 }

 // Need to wait until the parent shard finished
-func (sc *ShardConsumer) waitOnParentShard(shard *shardStatus) error {
+func (sc *ShardConsumer) waitOnParentShard(shard *par.ShardStatus) error {
 	if len(shard.ParentShardId) == 0 {
 		return nil
 	}

-	pshard := &shardStatus{
+	pshard := &par.ShardStatus{
 		ID:  shard.ParentShardId,
-		mux: &sync.Mutex{},
+		Mux: &sync.Mutex{},
 	}

 	for {
@ -271,7 +273,7 @@ func (sc *ShardConsumer) waitOnParentShard(shard *shardStatus) error {
 		}

 		// Parent shard is finished.
-		if pshard.Checkpoint == SHARD_END {
+		if pshard.Checkpoint == chk.SHARD_END {
 			return nil
 		}

@ -280,9 +282,9 @@ func (sc *ShardConsumer) waitOnParentShard(shard *shardStatus) error {
 }

 // Cleanup the internal lease cache
-func (sc *ShardConsumer) releaseLease(shard *shardStatus) {
+func (sc *ShardConsumer) releaseLease(shard *par.ShardStatus) {
 	log.Infof("Release lease for shard %s", shard.ID)
-	shard.setLeaseOwner("")
+	shard.SetLeaseOwner("")
 	// reporting lease lose metrics
 	sc.mService.LeaseLost(shard.ID)
 }
--- a/clientlibrary/worker/worker-custom.go
+++ b/clientlibrary/worker/worker-custom.go
@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2019 VMware, 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 worker
+
+import (
+	log "github.com/sirupsen/logrus"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/kinesis"
+	chk "github.com/vmware/vmware-go-kcl/clientlibrary/checkpoint"
+	"github.com/vmware/vmware-go-kcl/clientlibrary/config"
+	kcl "github.com/vmware/vmware-go-kcl/clientlibrary/interfaces"
+	"github.com/vmware/vmware-go-kcl/clientlibrary/metrics"
+)
+
+// NewCustomWorker constructs a Worker instance for processing Kinesis stream data by directly inject custom cjheckpointer.
+func NewCustomWorker(factory kcl.IRecordProcessorFactory, kclConfig *config.KinesisClientLibConfiguration,
+	checkpointer chk.Checkpointer, metricsConfig *metrics.MonitoringConfiguration) *Worker {
+	w := &Worker{
+		streamName:       kclConfig.StreamName,
+		regionName:       kclConfig.RegionName,
+		workerID:         kclConfig.WorkerID,
+		processorFactory: factory,
+		kclConfig:        kclConfig,
+		checkpointer:     checkpointer,
+		metricsConfig:    metricsConfig,
+	}
+
+	// create session for Kinesis
+	log.Info("Creating Kinesis session")
+
+	s, err := session.NewSession(&aws.Config{
+		Region:      aws.String(w.regionName),
+		Endpoint:    &kclConfig.KinesisEndpoint,
+		Credentials: kclConfig.KinesisCredentials,
+	})
+
+	if err != nil {
+		// no need to move forward
+		log.Fatalf("Failed in getting Kinesis session for creating Worker: %+v", err)
+	}
+	w.kc = kinesis.New(s)
+
+	if w.metricsConfig == nil {
+		// "" means noop monitor service. i.e. not emitting any metrics.
+		w.metricsConfig = &metrics.MonitoringConfiguration{MonitoringService: ""}
+	}
+	return w
+}
--- a/clientlibrary/worker/worker.go
+++ b/clientlibrary/worker/worker.go
@ -40,40 +40,16 @@ import (
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/dynamodb"
-	"github.com/aws/aws-sdk-go/service/dynamodb/dynamodbiface"
 	"github.com/aws/aws-sdk-go/service/kinesis"
 	"github.com/aws/aws-sdk-go/service/kinesis/kinesisiface"

+	chk "github.com/vmware/vmware-go-kcl/clientlibrary/checkpoint"
 	"github.com/vmware/vmware-go-kcl/clientlibrary/config"
 	kcl "github.com/vmware/vmware-go-kcl/clientlibrary/interfaces"
 	"github.com/vmware/vmware-go-kcl/clientlibrary/metrics"
+	par "github.com/vmware/vmware-go-kcl/clientlibrary/partition"
 )

-type shardStatus struct {
-	ID            string
-	ParentShardId string
-	Checkpoint    string
-	AssignedTo    string
-	mux           *sync.Mutex
-	LeaseTimeout  time.Time
-	// Shard Range
-	StartingSequenceNumber string
-	// child shard doesn't have end sequence number
-	EndingSequenceNumber string
-}
-
-func (ss *shardStatus) getLeaseOwner() string {
-	ss.mux.Lock()
-	defer ss.mux.Unlock()
-	return ss.AssignedTo
-}
-
-func (ss *shardStatus) setLeaseOwner(owner string) {
-	ss.mux.Lock()
-	defer ss.mux.Unlock()
-	ss.AssignedTo = owner
-}
-
 /**
 * Worker is the high level class that Kinesis applications use to start processing data. It initializes and oversees
 * different components (e.g. syncing shard and lease information, tracking shard assignments, and processing data from
@ -87,14 +63,13 @@ type Worker struct {
 	processorFactory kcl.IRecordProcessorFactory
 	kclConfig        *config.KinesisClientLibConfiguration
 	kc               kinesisiface.KinesisAPI
-	dynamo           dynamodbiface.DynamoDBAPI
-	checkpointer     Checkpointer
+	checkpointer     chk.Checkpointer

 	stop      *chan struct{}
 	waitGroup *sync.WaitGroup
 	sigs      *chan os.Signal

-	shardStatus map[string]*shardStatus
+	shardStatus map[string]*par.ShardStatus

 	metricsConfig *metrics.MonitoringConfiguration
 	mService      metrics.MonitoringService
@ -139,8 +114,7 @@ func NewWorker(factory kcl.IRecordProcessorFactory, kclConfig *config.KinesisCli
 		log.Fatalf("Failed in getting DynamoDB session for creating Worker: %+v", err)
 	}

-	w.dynamo = dynamodb.New(s)
-	w.checkpointer = NewDynamoCheckpoint(w.dynamo, kclConfig)
+	w.checkpointer = chk.NewDynamoCheckpoint(dynamodb.New(s), kclConfig)

 	if w.metricsConfig == nil {
 		// "" means noop monitor service. i.e. not emitting any metrics.
@ -209,7 +183,7 @@ func (w *Worker) initialize() error {
 		return err
 	}

-	w.shardStatus = make(map[string]*shardStatus)
+	w.shardStatus = make(map[string]*par.ShardStatus)

 	sigs := make(chan os.Signal, 1)
 	w.sigs = &sigs
@ -227,7 +201,7 @@ func (w *Worker) initialize() error {
 }

 // newShardConsumer to create a shard consumer instance
-func (w *Worker) newShardConsumer(shard *shardStatus) *ShardConsumer {
+func (w *Worker) newShardConsumer(shard *par.ShardStatus) *ShardConsumer {
 	return &ShardConsumer{
 		streamName:      w.streamName,
 		shard:           shard,
@ -258,7 +232,7 @@ func (w *Worker) eventLoop() {
 		// Count the number of leases hold by this worker excluding the processed shard
 		counter := 0
 		for _, shard := range w.shardStatus {
-			if shard.getLeaseOwner() == w.workerID && shard.Checkpoint != SHARD_END {
+			if shard.GetLeaseOwner() == w.workerID && shard.Checkpoint != chk.SHARD_END {
 				counter++
 			}
 		}
@ -267,14 +241,14 @@ func (w *Worker) eventLoop() {
 		if counter < w.kclConfig.MaxLeasesForWorker {
 			for _, shard := range w.shardStatus {
 				// already owner of the shard
-				if shard.getLeaseOwner() == w.workerID {
+				if shard.GetLeaseOwner() == w.workerID {
 					continue
 				}

 				err := w.checkpointer.FetchCheckpoint(shard)
 				if err != nil {
 					// checkpoint may not existed yet is not an error condition.
-					if err != ErrSequenceIDNotFound {
+					if err != chk.ErrSequenceIDNotFound {
 						log.Errorf(" Error: %+v", err)
 						// move on to next shard
 						continue
@ -282,14 +256,14 @@ func (w *Worker) eventLoop() {
 				}

 				// The shard is closed and we have processed all records
-				if shard.Checkpoint == SHARD_END {
+				if shard.Checkpoint == chk.SHARD_END {
 					continue
 				}

 				err = w.checkpointer.GetLease(shard, w.workerID)
 				if err != nil {
 					// cannot get lease on the shard
-					if err.Error() != ErrLeaseNotAquired {
+					if err.Error() != chk.ErrLeaseNotAquired {
 						log.Error(err)
 					}
 					continue
@ -351,10 +325,10 @@ func (w *Worker) getShardIDs(startShardID string, shardInfo map[string]bool) err
 		// found new shard
 		if _, ok := w.shardStatus[*s.ShardId]; !ok {
 			log.Infof("Found new shard with id %s", *s.ShardId)
-			w.shardStatus[*s.ShardId] = &shardStatus{
+			w.shardStatus[*s.ShardId] = &par.ShardStatus{
 				ID:                     *s.ShardId,
 				ParentShardId:          aws.StringValue(s.ParentShardId),
-				mux:                    &sync.Mutex{},
+				Mux:                    &sync.Mutex{},
 				StartingSequenceNumber: aws.StringValue(s.SequenceNumberRange.StartingSequenceNumber),
 				EndingSequenceNumber:   aws.StringValue(s.SequenceNumberRange.EndingSequenceNumber),
 			}
--- a/clientlibrary/worker/worker_custom_test.go
+++ b/clientlibrary/worker/worker_custom_test.go
@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2018 VMware, 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 worker
+
+import (
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/dynamodb"
+	"os"
+	"testing"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/stretchr/testify/assert"
+	chk "github.com/vmware/vmware-go-kcl/clientlibrary/checkpoint"
+	cfg "github.com/vmware/vmware-go-kcl/clientlibrary/config"
+	"github.com/vmware/vmware-go-kcl/clientlibrary/utils"
+)
+
+func TestCustomWorker(t *testing.T) {
+	kclConfig := cfg.NewKinesisClientLibConfig("appName", streamName, regionName, workerID).
+		WithInitialPositionInStream(cfg.LATEST).
+		WithMaxRecords(10).
+		WithMaxLeasesForWorker(1).
+		WithShardSyncIntervalMillis(5000).
+		WithFailoverTimeMillis(300000).
+		WithMetricsBufferTimeMillis(10000).
+		WithMetricsMaxQueueSize(20)
+
+	log.SetOutput(os.Stdout)
+	log.SetLevel(log.DebugLevel)
+
+	assert.Equal(t, regionName, kclConfig.RegionName)
+	assert.Equal(t, streamName, kclConfig.StreamName)
+
+	// configure cloudwatch as metrics system
+	metricsConfig := getMetricsConfig(kclConfig, metricsSystem)
+
+	// create dynamodb checkpointer.
+	s, err := session.NewSession(&aws.Config{
+		Region:      aws.String(regionName),
+		Endpoint:    &kclConfig.DynamoDBEndpoint,
+		Credentials: kclConfig.DynamoDBCredentials,
+	})
+
+	if err != nil {
+		// no need to move forward
+		log.Fatalf("Failed in getting DynamoDB session for creating Worker: %+v", err)
+	}
+
+	checkpointer := chk.NewDynamoCheckpoint(dynamodb.New(s), kclConfig)
+
+	worker := NewCustomWorker(recordProcessorFactory(t), kclConfig, checkpointer, metricsConfig)
+	assert.Equal(t, regionName, worker.regionName)
+	assert.Equal(t, streamName, worker.streamName)
+
+	err = worker.Start()
+	assert.Nil(t, err)
+
+	// Put some data into stream.
+	for i := 0; i < 100; i++ {
+		// Use random string as partition key to ensure even distribution across shards
+		err := worker.Publish(streamName, utils.RandStringBytesMaskImpr(10), []byte(specstr))
+		if err != nil {
+			t.Errorf("Errorin Publish. %+v", err)
+		}
+	}
+
+	// wait a few seconds before shutdown processing
+	time.Sleep(10 * time.Second)
+	worker.Shutdown()
+}
--- a/support/toolchain/HyperMake
+++ b/support/toolchain/HyperMake
@ -25,4 +25,4 @@ settings:
  default-targets:
    - rebuild-toolchain
  docker:
-    image: 'vmware/go-kcl-toolchain:0.1.1'
+    image: 'vmware/go-kcl-toolchain:0.1.2'
--- a/support/toolchain/docker/Dockerfile
+++ b/support/toolchain/docker/Dockerfile
@ -1,4 +1,4 @@
-FROM golang:1.11
+FROM golang:1.12
 ENV PATH /go/bin:/src/bin:/root/go/bin:/usr/local/go/bin:$PATH
 ENV GOPATH /go:/src
 RUN go get -v github.com/alecthomas/gometalinter && \