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Merge pull request #21 from vmware/spentakota_callGetRecordsAPI

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fix: Handle ProvisionedThroughputExceededException throttling
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spentakota 2023-01-24 17:12:39 -08:00 committed by GitHub
commit 42881449ce
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4 changed files with 249 additions and 10 deletions
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6
clientlibrary/config/config.go
View file

@ -136,6 +136,9 @@ const (
// DefaultLeaseSyncingIntervalMillis Number of milliseconds to wait before syncing with lease table (dynamodDB)
DefaultLeaseSyncingIntervalMillis = 60000
// DefaultMaxRetryCount The default maximum number of retries in case of error
DefaultMaxRetryCount = 5
)
type (
@ -283,6 +286,9 @@ type (
// LeaseSyncingTimeInterval The number of milliseconds to wait before syncing with lease table (dynamoDB)
LeaseSyncingTimeIntervalMillis int
// MaxRetryCount The maximum number of retries in case of error
MaxRetryCount int
}
)

8
clientlibrary/config/kcl-config.go
View file

@ -102,6 +102,7 @@ func NewKinesisClientLibConfigWithCredentials(applicationName, streamName, regio
LeaseStealingIntervalMillis: DefaultLeaseStealingIntervalMillis,
LeaseStealingClaimTimeoutMillis: DefaultLeaseStealingClaimTimeoutMillis,
LeaseSyncingTimeIntervalMillis: DefaultLeaseSyncingIntervalMillis,
MaxRetryCount: DefaultMaxRetryCount,
Logger: logger.GetDefaultLogger(),
}
}
@ -211,6 +212,13 @@ func (c *KinesisClientLibConfiguration) WithLogger(logger logger.Logger) *Kinesi
return c
}
// WithMaxRetryCount sets the max retry count in case of error.
func (c *KinesisClientLibConfiguration) WithMaxRetryCount(maxRetryCount int) *KinesisClientLibConfiguration {
checkIsValuePositive("maxRetryCount", maxRetryCount)
c.MaxRetryCount = maxRetryCount
return c
}
// WithMonitoringService sets the monitoring service to use to publish metrics.
func (c *KinesisClientLibConfiguration) WithMonitoringService(mService metrics.MonitoringService) *KinesisClientLibConfiguration {
// Nil case is handled downward (at worker creation) so no need to do it here.

133
clientlibrary/worker/polling-shard-consumer.go
View file

@ -44,14 +44,33 @@ import (
"github.com/vmware/vmware-go-kcl-v2/clientlibrary/metrics"
)
const (
kinesisReadTPSLimit = 5
MaxBytes = 10000000
MaxBytesPerSecond = 2000000
BytesToMbConversion = 1000000
)
var (
rateLimitTimeNow = time.Now
rateLimitTimeSince = time.Since
localTPSExceededError = errors.New("Error GetRecords TPS Exceeded")
maxBytesExceededError = errors.New("Error GetRecords Max Bytes For Call Period Exceeded")
)
// PollingShardConsumer is responsible for polling data records from a (specified) shard.
// Note: PollingShardConsumer only deal with one shard.
type PollingShardConsumer struct {
commonShardConsumer
streamName string
stop *chan struct{}
consumerID string
mService metrics.MonitoringService
streamName string
stop *chan struct{}
consumerID string
mService metrics.MonitoringService
currTime time.Time
callsLeft int
remBytes int
lastCheckTime time.Time
bytesRead int
}
func (sc *PollingShardConsumer) getShardIterator() (*string, error) {
@ -108,6 +127,12 @@ func (sc *PollingShardConsumer) getRecords() error {
recordCheckpointer := NewRecordProcessorCheckpoint(sc.shard, sc.checkpointer)
retriedErrors := 0
// define API call rate limit starting window
sc.currTime = rateLimitTimeNow()
sc.callsLeft = kinesisReadTPSLimit
sc.bytesRead = 0
sc.remBytes = MaxBytes
for {
if time.Now().UTC().After(sc.shard.GetLeaseTimeout().Add(-time.Duration(sc.kclConfig.LeaseRefreshPeriodMillis) * time.Millisecond)) {
log.Debugf("Refreshing lease on shard: %s for worker: %s", sc.shard.ID, sc.consumerID)
@ -135,14 +160,47 @@ func (sc *PollingShardConsumer) getRecords() error {
Limit: aws.Int32(int32(sc.kclConfig.MaxRecords)),
ShardIterator: shardIterator,
}
getResp, err := sc.callGetRecordsAPI(getRecordsArgs)
getResp, coolDownPeriod, err := sc.callGetRecordsAPI(getRecordsArgs)
if err != nil {
//aws-sdk-go-v2 https://github.com/aws/aws-sdk-go-v2/blob/main/CHANGELOG.md#error-handling
var throughputExceededErr *types.ProvisionedThroughputExceededException
var kmsThrottlingErr *types.KMSThrottlingException
if errors.As(err, &throughputExceededErr) || errors.As(err, &kmsThrottlingErr) {
if errors.As(err, &throughputExceededErr) {
retriedErrors++
if retriedErrors > sc.kclConfig.MaxRetryCount {
log.Errorf("message", "Throughput Exceeded Error: "+
"reached max retry count getting records from shard",
"shardId", sc.shard.ID,
"retryCount", retriedErrors,
"error", err)
return err
}
// If there is insufficient provisioned throughput on the stream,
// subsequent calls made within the next 1 second throw ProvisionedThroughputExceededException.
// ref: https://docs.aws.amazon.com/streams/latest/dev/service-sizes-and-limits.html
sc.waitASecond(sc.currTime)
continue
}
if err == localTPSExceededError {
sc.waitASecond(sc.currTime)
continue
}
if err == maxBytesExceededError {
time.Sleep(time.Duration(coolDownPeriod) * time.Second)
continue
}
if errors.As(err, &kmsThrottlingErr) {
log.Errorf("Error getting records from shard %v: %+v", sc.shard.ID, err)
retriedErrors++
// Greater than MaxRetryCount so we get the last retry
if retriedErrors > sc.kclConfig.MaxRetryCount {
log.Errorf("message", "KMS Throttling Error: "+
"reached max retry count getting records from shard",
"shardId", sc.shard.ID,
"retryCount", retriedErrors,
"error", err)
return err
}
// exponential backoff
// https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Programming.Errors.html#Programming.Errors.RetryAndBackoff
time.Sleep(time.Duration(math.Exp2(float64(retriedErrors))*100) * time.Millisecond)
@ -182,7 +240,64 @@ func (sc *PollingShardConsumer) getRecords() error {
}
}
func (sc *PollingShardConsumer) callGetRecordsAPI(gri *kinesis.GetRecordsInput) (*kinesis.GetRecordsOutput, error) {
getResp, err := sc.kc.GetRecords(context.TODO(), gri)
return getResp, err
func (sc *PollingShardConsumer) waitASecond(timePassed time.Time) {
waitTime := time.Since(timePassed)
if waitTime < time.Second {
time.Sleep(time.Second - waitTime)
}
}
func (sc *PollingShardConsumer) checkCoolOffPeriod() (int, error) {
// Each shard can support up to a maximum total data read rate of 2 MB per second via GetRecords.
// If a call to GetRecords returns 10 MB, subsequent calls made within the next 5 seconds throw an exception.
// ref: https://docs.aws.amazon.com/streams/latest/dev/service-sizes-and-limits.html
// check for overspending of byte budget from getRecords call
currentTime := rateLimitTimeNow()
secondsPassed := currentTime.Sub(sc.lastCheckTime).Seconds()
sc.lastCheckTime = currentTime
sc.remBytes += int(secondsPassed * MaxBytesPerSecond)
transactionReadRate := float64(sc.bytesRead) / (secondsPassed * BytesToMbConversion)
if sc.remBytes > MaxBytes {
sc.remBytes = MaxBytes
}
if sc.remBytes <= sc.bytesRead || transactionReadRate > 2 {
// Wait until cool down period has passed to prevent ProvisionedThroughputExceededException
coolDown := sc.bytesRead / MaxBytesPerSecond
return coolDown, maxBytesExceededError
} else {
sc.remBytes -= sc.bytesRead
}
return 0, nil
}
func (sc *PollingShardConsumer) callGetRecordsAPI(gri *kinesis.GetRecordsInput) (*kinesis.GetRecordsOutput, int, error) {
if sc.bytesRead != 0 {
coolDownPeriod, err := sc.checkCoolOffPeriod()
if err != nil {
return nil, coolDownPeriod, err
}
}
// every new second, we get a fresh set of calls
if rateLimitTimeSince(sc.currTime) > time.Second {
sc.callsLeft = kinesisReadTPSLimit
sc.currTime = rateLimitTimeNow()
}
if sc.callsLeft < 1 {
return nil, 0, localTPSExceededError
}
getResp, err := sc.kc.GetRecords(context.TODO(), gri)
sc.callsLeft--
// Calculate size of records from read transaction
sc.bytesRead = 0
for _, record := range getResp.Records {
sc.bytesRead += len(record.Data)
}
if sc.lastCheckTime.IsZero() {
sc.lastCheckTime = rateLimitTimeNow()
}
return getResp, 0, err
}

112
clientlibrary/worker/polling-shard-consumer_test.go
View file

@ -22,6 +22,7 @@ package worker
import (
"context"
"testing"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/service/kinesis"
@ -40,10 +41,119 @@ func TestCallGetRecordsAPI(t *testing.T) {
gri := kinesis.GetRecordsInput{
ShardIterator: aws.String("shard-iterator-01"),
}
out, err := psc.callGetRecordsAPI(&gri)
out, _, err := psc.callGetRecordsAPI(&gri)
assert.Nil(t, err)
assert.Equal(t, &ret, out)
m1.AssertExpectations(t)
// check that localTPSExceededError is thrown when trying more than 5 TPS
m2 := MockKinesisSubscriberGetter{}
psc2 := PollingShardConsumer{
commonShardConsumer: commonShardConsumer{kc: &m2},
callsLeft: 0,
}
rateLimitTimeSince = func(t time.Time) time.Duration {
return 500 * time.Millisecond
}
out2, _, err2 := psc2.callGetRecordsAPI(&gri)
assert.Nil(t, out2)
assert.ErrorIs(t, err2, localTPSExceededError)
m2.AssertExpectations(t)
// check that getRecords is called normally in bytesRead = 0 case
m3 := MockKinesisSubscriberGetter{}
ret3 := kinesis.GetRecordsOutput{}
m3.On("GetRecords", mock.Anything, mock.Anything, mock.Anything).Return(&ret3, nil)
psc3 := PollingShardConsumer{
commonShardConsumer: commonShardConsumer{kc: &m3},
callsLeft: 2,
bytesRead: 0,
}
rateLimitTimeSince = func(t time.Time) time.Duration {
return 2 * time.Second
}
out3, checkSleepVal, err3 := psc3.callGetRecordsAPI(&gri)
assert.Nil(t, err3)
assert.Equal(t, checkSleepVal, 0)
assert.Equal(t, &ret3, out3)
m3.AssertExpectations(t)
// check that correct cool off period is taken for 10mb in 1 second
testTime := time.Now()
m4 := MockKinesisSubscriberGetter{}
psc4 := PollingShardConsumer{
commonShardConsumer: commonShardConsumer{kc: &m4},
callsLeft: 2,
bytesRead: MaxBytes,
lastCheckTime: testTime,
remBytes: MaxBytes,
}
rateLimitTimeSince = func(t time.Time) time.Duration {
return 2 * time.Second
}
rateLimitTimeNow = func() time.Time {
return testTime.Add(time.Second)
}
out4, checkSleepVal2, err4 := psc4.callGetRecordsAPI(&gri)
assert.Nil(t, out4)
assert.Equal(t, maxBytesExceededError, err4)
m4.AssertExpectations(t)
if checkSleepVal2 != 5 {
t.Errorf("Incorrect Cool Off Period: %v", checkSleepVal2)
}
// check that no cool off period is taken for 6mb in 3 seconds
testTime2 := time.Now()
m5 := MockKinesisSubscriberGetter{}
ret5 := kinesis.GetRecordsOutput{}
m5.On("GetRecords", mock.Anything, mock.Anything, mock.Anything).Return(&ret5, nil)
psc5 := PollingShardConsumer{
commonShardConsumer: commonShardConsumer{kc: &m5},
callsLeft: 2,
bytesRead: MaxBytesPerSecond * 3,
lastCheckTime: testTime2,
remBytes: MaxBytes,
}
rateLimitTimeSince = func(t time.Time) time.Duration {
return 3 * time.Second
}
rateLimitTimeNow = func() time.Time {
return testTime2.Add(time.Second * 3)
}
out5, checkSleepVal3, err5 := psc5.callGetRecordsAPI(&gri)
assert.Nil(t, err5)
assert.Equal(t, checkSleepVal3, 0)
assert.Equal(t, &ret5, out5)
m5.AssertExpectations(t)
// check for correct cool off period with 8mb in .2 seconds with 6mb remaining
testTime3 := time.Now()
m6 := MockKinesisSubscriberGetter{}
psc6 := PollingShardConsumer{
commonShardConsumer: commonShardConsumer{kc: &m6},
callsLeft: 2,
bytesRead: MaxBytesPerSecond * 4,
lastCheckTime: testTime3,
remBytes: MaxBytesPerSecond * 3,
}
rateLimitTimeSince = func(t time.Time) time.Duration {
return 3 * time.Second
}
rateLimitTimeNow = func() time.Time {
return testTime3.Add(time.Second / 5)
}
out6, checkSleepVal4, err6 := psc6.callGetRecordsAPI(&gri)
assert.Nil(t, out6)
assert.Equal(t, err6, maxBytesExceededError)
m5.AssertExpectations(t)
if checkSleepVal4 != 4 {
t.Errorf("Incorrect Cool Off Period: %v", checkSleepVal4)
}
// restore original func
rateLimitTimeNow = time.Now
rateLimitTimeSince = time.Since
}
type MockKinesisSubscriberGetter struct {