Merge branch 'hw-updates' into ez-recover-errors

Conflicts:
	pipeline.go
	redshift_basic_emitter.go

awsbackoff.go

@@ -0,0 +1,104 @@
+package connector
+
+import (
+	"log"
+	"math"
+	"net"
+	"net/url"
+	"reflect"
+	"regexp"
+	"time"
+
+	"github.com/ezoic/go-kinesis"
+	l4g "github.com/ezoic/log4go"
+	"github.com/lib/pq"
+)
+
+type isRecoverableErrorFunc func(error) bool
+
+func kinesisIsRecoverableError(err error) bool {
+	recoverableErrorCodes := map[string]bool{
+		"ProvisionedThroughputExceededException": true,
+		"InternalFailure":                        true,
+		"Throttling":                             true,
+		"ServiceUnavailable":                     true,
+		//"ExpiredIteratorException":               true,
+	}
+	r := false
+	cErr, ok := err.(*kinesis.Error)
+	if ok && recoverableErrorCodes[cErr.Code] == true {
+		r = true
+	}
+	return r
+}
+
+func urlIsRecoverableError(err error) bool {
+	r := false
+	_, ok := err.(*url.Error)
+	if ok {
+		r = true
+	}
+	return r
+}
+
+func netIsRecoverableError(err error) bool {
+	recoverableErrors := map[string]bool{
+		"connection reset by peer": true,
+	}
+	r := false
+	cErr, ok := err.(*net.OpError)
+	if ok && recoverableErrors[cErr.Err.Error()] == true {
+		r = true
+	}
+	return r
+}
+
+var redshiftRecoverableErrors = []*regexp.Regexp{
+	regexp.MustCompile("The specified S3 prefix '.*?' does not exist"),
+}
+
+func redshiftIsRecoverableError(err error) bool {
+	r := false
+	if cErr, ok := err.(pq.Error); ok {
+		for _, re := range redshiftRecoverableErrors {
+			if re.MatchString(cErr.Message) {
+				r = true
+				break
+			}
+		}
+	}
+	return r
+}
+
+var isRecoverableErrors = []isRecoverableErrorFunc{
+	kinesisIsRecoverableError, netIsRecoverableError, urlIsRecoverableError, redshiftIsRecoverableError,
+}
+
+// this determines whether the error is recoverable
+func isRecoverableError(err error) bool {
+	r := false
+
+	log.Printf("isRecoverableError, type %s, value (%#v)\n", reflect.TypeOf(err).String(), err)
+
+	for _, errF := range isRecoverableErrors {
+		r = errF(err)
+		if r {
+			break
+		}
+	}
+
+	return r
+}
+
+// handle the aws exponential backoff
+func handleAwsWaitTimeExp(attempts int) {
+
+	//http://docs.aws.amazon.com/general/latest/gr/api-retries.html
+	// wait up to 5 minutes based on the aws exponential backoff algorithm
+	if attempts > 0 {
+		waitTime := time.Duration(math.Min(100*math.Pow(2, float64(attempts)), 300000)) * time.Millisecond
+		l4g.Finest("handleAwsWaitTimeExp:%s", waitTime.String())
+		time.Sleep(waitTime)
+	}
+
+}

awsbackoff_test.go

@@ -0,0 +1,43 @@
+package connector
+
+import (
+	"fmt"
+	"net"
+	"testing"
+
+	"github.com/ezoic/go-kinesis"
+	"github.com/lib/pq"
+)
+
+func Test_isRecoverableError(t *testing.T) {
+
+	testCases := []struct {
+		err           error
+		isRecoverable bool
+	}{
+		{err: &kinesis.Error{Code: "ProvisionedThroughputExceededException"}, isRecoverable: true},
+		{err: &kinesis.Error{Code: "Throttling"}, isRecoverable: true},
+		{err: &kinesis.Error{Code: "ServiceUnavailable"}, isRecoverable: true},
+		{err: &kinesis.Error{Code: "ExpiredIteratorException"}, isRecoverable: false},
+		{err: &net.OpError{Err: fmt.Errorf("connection reset by peer")}, isRecoverable: true},
+		{err: &net.OpError{Err: fmt.Errorf("unexpected error")}, isRecoverable: false},
+		{err: fmt.Errorf("an arbitrary error"), isRecoverable: false},
+		{err: pq.Error{Message: "The specified S3 prefix 'somefilethatismissing' does not exist"}, isRecoverable: true},
+		{err: pq.Error{Message: "Some other pq error"}, isRecoverable: false},
+
+		//"InternalFailure":                        true,
+		//"Throttling":                             true,
+		//"ServiceUnavailable":                     true,
+		////"ExpiredIteratorException":               true,
+		//{err: *kinesis.Error{Code:""}}
+	}
+
+	for idx, tc := range testCases {
+
+		isRecoverable := isRecoverableError(tc.err)
+		if isRecoverable != tc.isRecoverable {
+			t.Errorf("test case %d: isRecoverable expected %t, actual %t, for error %+v", idx, tc.isRecoverable, isRecoverable, tc.err)
+		}
+
+	}
+}

kinesis.go

@@ -1,10 +1,10 @@
 package connector
 
 import (
-	"fmt"
 	"time"
 
-	"github.com/sendgridlabs/go-kinesis"
+	"github.com/ezoic/go-kinesis"
+	l4g "github.com/ezoic/log4go"
 )
 
 // CreateStream creates a new Kinesis stream (uses existing stream if exists) and
@@ -14,7 +14,7 @@ func CreateStream(k *kinesis.Kinesis, streamName string, shardCount int) {
 		err := k.CreateStream(streamName, shardCount)
 
 		if err != nil {
-			fmt.Printf("CreateStream ERROR: %v\n", err)
+			l4g.Error("CreateStream ERROR: %v", err)
 			return
 		}
 	}
@@ -27,7 +27,7 @@ func CreateStream(k *kinesis.Kinesis, streamName string, shardCount int) {
 		args.Add("StreamName", streamName)
 		resp, _ = k.DescribeStream(args)
 		streamStatus := resp.StreamDescription.StreamStatus
-		fmt.Printf("Stream [%v] is %v\n", streamName, streamStatus)
+		l4g.Info("Stream [%v] is %v", streamName, streamStatus)
 
 		if streamStatus != "ACTIVE" {
 			time.Sleep(4 * time.Second)
@@ -43,7 +43,7 @@ func StreamExists(k *kinesis.Kinesis, streamName string) bool {
 	args := kinesis.NewArgs()
 	resp, err := k.ListStreams(args)
 	if err != nil {
-		fmt.Printf("ListStream ERROR: %v\n", err)
+		l4g.Error("ListStream ERROR: %v", err)
 		return false
 	}
 	for _, s := range resp.StreamNames {

mysql_checkpoint.go

@@ -0,0 +1,66 @@
+package connector
+
+import (
+	"database/sql"
+	"fmt"
+
+	l4g "github.com/ezoic/log4go"
+	_ "github.com/go-sql-driver/mysql"
+)
+
+// MysqlCheckpoint implements the Checkpont interface.
+// This class is used to enable the Pipeline.ProcessShard to checkpoint their progress.
+type MysqlCheckpoint struct {
+	AppName    string
+	StreamName string
+	TableName  string
+	Db         *sql.DB
+
+	sequenceNumber string
+}
+
+// CheckpointExists determines if a checkpoint for a particular Shard exists.
+// Typically used to determine whether we should start processing the shard with
+// TRIM_HORIZON or AFTER_SEQUENCE_NUMBER (if checkpoint exists).
+func (c *MysqlCheckpoint) CheckpointExists(shardID string) bool {
+
+	l4g.Finest("SELECT sequence_number FROM " + c.TableName + " WHERE checkpoint_key = ?")
+
+	row := c.Db.QueryRow("SELECT sequence_number FROM "+c.TableName+" WHERE checkpoint_key = ?", c.key(shardID))
+	var val string
+	err := row.Scan(&val)
+	if err == nil {
+		l4g.Finest("sequence:%s", val)
+		c.sequenceNumber = val
+		return true
+	}
+
+	if err == sql.ErrNoRows {
+		return false
+	}
+
+	// something bad happened, better blow up the process
+	panic(err)
+}
+
+// SequenceNumber returns the current checkpoint stored for the specified shard.
+func (c *MysqlCheckpoint) SequenceNumber() string {
+	return c.sequenceNumber
+}
+
+// SetCheckpoint stores a checkpoint for a shard (e.g. sequence number of last record processed by application).
+// Upon failover, record processing is resumed from this point.
+func (c *MysqlCheckpoint) SetCheckpoint(shardID string, sequenceNumber string) {
+
+	_, err := c.Db.Exec("INSERT INTO "+c.TableName+" (sequence_number, checkpoint_key) VALUES (?, ?) ON DUPLICATE KEY UPDATE sequence_number = ?", sequenceNumber, c.key(shardID), sequenceNumber)
+	if err != nil {
+		panic(err)
+	}
+	c.sequenceNumber = sequenceNumber
+
+}
+
+// key generates a unique mysql key for storage of Checkpoint.
+func (c *MysqlCheckpoint) key(shardID string) string {
+	return fmt.Sprintf("%v:checkpoint:%v:%v", c.AppName, c.StreamName, shardID)
+}

mysql_checkpoint_test.go

@@ -0,0 +1,59 @@
+package connector
+
+import (
+	"database/sql"
+	"os"
+	"testing"
+)
+
+func Test_MysqlKey(t *testing.T) {
+	k := "app:checkpoint:stream:shard"
+	c := MysqlCheckpoint{AppName: "app", StreamName: "stream"}
+
+	r := c.key("shard")
+
+	if r != k {
+		t.Errorf("key() = %v, want %v", k, r)
+	}
+}
+
+func Test_MysqlCheckpointExists(t *testing.T) {
+	rc, _ := sql.Open("mysql", os.Getenv("CHECKPOINT_MYSQL_DSN"))
+	k := "app:checkpoint:stream:shard"
+
+	_, err := rc.Exec("INSERT INTO KinesisConnector.TestCheckpoint (sequence_number, checkpoint_key) VALUES (?, ?) ON DUPLICATE KEY UPDATE sequence_number = ?", "fakeSeqNum", k, "fakeSeqNum")
+	if err != nil {
+		t.Fatalf("cannot insert checkpoint into db manually, %s", err)
+	}
+	c := MysqlCheckpoint{AppName: "app", StreamName: "stream", TableName: "KinesisConnector.TestCheckpoint", Db: rc}
+
+	r := c.CheckpointExists("shard")
+
+	if r != true {
+		t.Errorf("CheckpointExists() = %v, want %v", false, r)
+	}
+
+	rc.Exec("DELETE FROM KinesisConnector.TestCheckpoint WHERE checkpoint_key = ?", k)
+}
+
+func Test_MysqlSetCheckpoint(t *testing.T) {
+	k := "app:checkpoint:stream:shard"
+
+	rc, _ := sql.Open("mysql", os.Getenv("CHECKPOINT_MYSQL_DSN"))
+
+	c := MysqlCheckpoint{AppName: "app", StreamName: "stream", TableName: "KinesisConnector.TestCheckpoint", Db: rc}
+	c.SetCheckpoint("shard", "fakeSeqNum")
+
+	rslt := rc.QueryRow("SELECT sequence_number FROM KinesisConnector.TestCheckpoint WHERE checkpoint_key = ?", k)
+	var sequenceNumber string
+	err := rslt.Scan(&sequenceNumber)
+	if err != nil {
+		t.Fatalf("cannot scan row for checkpoint key, %s", err)
+	}
+
+	if sequenceNumber != "fakeSeqNum" {
+		t.Errorf("SetCheckpoint() = %v, want %v", "fakeSeqNum", sequenceNumber)
+	}
+
+	rc.Exec("DELETE FROM KinesisConnector.TestCheckpoint WHERE checkpoint_key = ?", k)
+}

pipeline.go

@@ -3,7 +3,8 @@ package connector
 import (
 	"time"
 
-	"github.com/sendgridlabs/go-kinesis"
+	"github.com/ezoic/go-kinesis"
+	l4g "github.com/ezoic/log4go"
 )
 
 // Pipeline is used as a record processor to configure a pipline.
@@ -12,12 +13,13 @@ import (
 // interface. It has a data type (Model) as Records come in as a byte[] and are transformed to a Model.
 // Then they are buffered in Model form and when the buffer is full, Models's are passed to the emitter.
 type Pipeline struct {
-	Buffer      Buffer
-	Checkpoint  Checkpoint
-	Emitter     Emitter
-	Filter      Filter
-	StreamName  string
-	Transformer Transformer
+	Buffer                    Buffer
+	Checkpoint                Checkpoint
+	Emitter                   Emitter
+	Filter                    Filter
+	StreamName                string
+	Transformer               Transformer
+	CheckpointFilteredRecords bool
 }
 
 // ProcessShard kicks off the process of a Kinesis Shard.
@@ -42,13 +44,31 @@ func (p Pipeline) ProcessShard(ksis *kinesis.Kinesis, shardID string) {
 
 	shardIterator := shardInfo.ShardIterator
 
+	consecutiveErrorAttempts := 0
+
 	for {
+
+		if consecutiveErrorAttempts > 50 {
+			log.Fatalln("Too many consecutive error attempts")
+		}
+
+		// handle the aws backoff stuff
+		handleAwsWaitTimeExp(consecutiveErrorAttempts)
+
 		args = kinesis.NewArgs()
 		args.Add("ShardIterator", shardIterator)
 		recordSet, err := ksis.GetRecords(args)
 
 		if err != nil {
-			logger.Fatalf("GetRecords ERROR: %v\n", err)
+			if isRecoverableError(err) {
+				p.Logger.Infof("recoverable error, %s", err)
+				consecutiveErrorAttempts++
+				continue
+			} else {
+				p.Logger.Fatalf("GetRecords ERROR: %v\n", err)
+			}
+		} else {
+			consecutiveErrorAttempts = 0
 		}
 
 		if len(recordSet.Records) > 0 {
@@ -64,6 +84,8 @@ func (p Pipeline) ProcessShard(ksis *kinesis.Kinesis, shardID string) {
 
 				if p.Filter.KeepRecord(r) {
 					p.Buffer.ProcessRecord(r, v.SequenceNumber)
+				} else if p.CheckpointFilteredRecords {
+					p.Buffer.ProcessRecord(nil, v.SequenceNumber)
 				}
 			}
 		} else if recordSet.NextShardIterator == "" || shardIterator == recordSet.NextShardIterator || err != nil {
@@ -74,7 +96,9 @@ func (p Pipeline) ProcessShard(ksis *kinesis.Kinesis, shardID string) {
 		}
 
 		if p.Buffer.ShouldFlush() {
-			p.Emitter.Emit(p.Buffer, p.Transformer)
+			if p.Buffer.NumRecordsInBuffer() > 0 {
+				p.Emitter.Emit(p.Buffer, p.Transformer)
+			}
 			p.Checkpoint.SetCheckpoint(shardID, p.Buffer.LastSequenceNumber())
 			p.Buffer.Flush()
 		}

record_buffer.go

@@ -20,7 +20,9 @@ func (b *RecordBuffer) ProcessRecord(record interface{}, sequenceNumber string)
 	b.lastSequenceNumber = sequenceNumber
 
 	if !b.sequenceExists(sequenceNumber) {
-		b.recordsInBuffer = append(b.recordsInBuffer, record)
+		if record != nil {
+			b.recordsInBuffer = append(b.recordsInBuffer, record)
+		}
 		b.sequencesInBuffer = append(b.sequencesInBuffer, sequenceNumber)
 	}
 }
@@ -32,7 +34,7 @@ func (b *RecordBuffer) Records() []interface{} {
 
 // NumRecordsInBuffer returns the number of messages in the buffer.
 func (b RecordBuffer) NumRecordsInBuffer() int {
-	return len(b.sequencesInBuffer)
+	return len(b.recordsInBuffer)
 }
 
 // Flush empties the buffer and resets the sequence counter.

redshift_basic_emitter.go

@@ -7,6 +7,7 @@ import (
 	"os"
 
 	// Postgres package is used when sql.Open is called
+	l4g "github.com/ezoic/log4go"
 	_ "github.com/lib/pq"
 )
 
@@ -18,7 +19,9 @@ type RedshiftBasicEmitter struct {
 	Format    string
 	Jsonpaths string
 	S3Bucket  string
+	S3Prefix  string
 	TableName string
+	Db        *sql.DB
 }
 
 // Emit is invoked when the buffer is full. This method leverages the S3Emitter and
@@ -27,27 +30,42 @@ func (e RedshiftBasicEmitter) Emit(b Buffer, t Transformer) {
 	s3Emitter := S3Emitter{S3Bucket: e.S3Bucket}
 	s3Emitter.Emit(b, t)
 	s3File := s3Emitter.S3FileName(b.FirstSequenceNumber(), b.LastSequenceNumber())
-	db, err := sql.Open("postgres", os.Getenv("REDSHIFT_URL"))
 
-	if err != nil {
-		logger.Fatalf("sql.Open ERROR: %v\n", err)
+	stmt := e.copyStatement(s3File)
+
+	var err error
+	for i := 0; i < 10; i++ {
+
+		// handle aws backoff, this may be necessary if, for example, the
+		// s3 file has not appeared to the database yet
+		handleAwsWaitTimeExp(i)
+
+		// load into the database
+		_, err := e.Db.Exec(stmt)
+
+		// if the request succeeded, or its an unrecoverable error, break out of the loop
+		// because we are done
+		if err == nil || isRecoverableError(err) == false {
+			break
+		}
+
+		// recoverable error, lets warn
+		l4g.Warn(err)
+
 	}
 
-	_, err = db.Exec(e.copyStatement(s3File))
-
 	if err != nil {
 		logger.Fatalf("db.Exec ERROR: %v\n", err)
 	}
 
 	logger.Printf("Redshift load completed.\n")
-	db.Close()
 }
 
 // Creates the SQL copy statement issued to Redshift cluster.
 func (e RedshiftBasicEmitter) copyStatement(s3File string) string {
 	b := new(bytes.Buffer)
 	b.WriteString(fmt.Sprintf("COPY %v ", e.TableName))
-	b.WriteString(fmt.Sprintf("FROM 's3://%v%v' ", e.S3Bucket, s3File))
+	b.WriteString(fmt.Sprintf("FROM 's3://%v/%v' ", e.S3Bucket, s3File))
 	b.WriteString(fmt.Sprintf("CREDENTIALS 'aws_access_key_id=%v;", os.Getenv("AWS_ACCESS_KEY")))
 	b.WriteString(fmt.Sprintf("aws_secret_access_key=%v' ", os.Getenv("AWS_SECRET_KEY")))
 	switch e.Format {
@@ -59,5 +77,6 @@ func (e RedshiftBasicEmitter) copyStatement(s3File string) string {
 		b.WriteString(fmt.Sprintf("DELIMITER '%v'", e.Delimiter))
 	}
 	b.WriteString(";")
+	l4g.Debug(b.String())
 	return b.String()
 }

redshift_basic_emitter_test.go

@@ -10,7 +10,7 @@ func TestCopyStatement(t *testing.T) {
 		S3Bucket:  "test_bucket",
 		TableName: "test_table",
 	}
-	f := e.copyStatement("/test.txt")
+	f := e.copyStatement("test.txt")
 
 	copyStatement := "COPY test_table FROM 's3://test_bucket/test.txt' CREDENTIALS 'aws_access_key_id=;aws_secret_access_key=' DELIMITER ',';"
 

redshift_manifest_emitter.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/crowdmob/goamz/aws"
 	"github.com/crowdmob/goamz/s3"
+	l4g "github.com/ezoic/log4go"
 	_ "github.com/lib/pq"
 )
 
@@ -118,7 +119,7 @@ func (e RedshiftManifestEmitter) writeManifestToS3(files []string, manifestFileN
 	content := e.generateManifestFile(files)
 	err := bucket.Put(manifestFileName, content, "text/plain", s3.Private, s3.Options{})
 	if err != nil {
-		fmt.Printf("Error occured while uploding to S3: %v\n", err)
+		l4g.Error("Error occured while uploding to S3: %v", err)
 	}
 }
 

s3_emitter.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/crowdmob/goamz/aws"
 	"github.com/crowdmob/goamz/s3"
+	l4g "github.com/ezoic/log4go"
 )
 
 // S3Emitter is an implementation of Emitter used to store files from a Kinesis stream in S3.
@@ -17,13 +18,18 @@ import (
 // dash. This struct requires the configuration of an S3 bucket and endpoint.
 type S3Emitter struct {
 	S3Bucket string
+	S3Prefix string
 }
 
 // S3FileName generates a file name based on the First and Last sequence numbers from the buffer. The current
 // UTC date (YYYY-MM-DD) is base of the path to logically group days of batches.
 func (e S3Emitter) S3FileName(firstSeq string, lastSeq string) string {
 	date := time.Now().UTC().Format("2006/01/02")
-	return fmt.Sprintf("%v/%v-%v", date, firstSeq, lastSeq)
+	if e.S3Prefix == "" {
+		return fmt.Sprintf("%v/%v-%v", date, firstSeq, lastSeq)
+	} else {
+		return fmt.Sprintf("%v/%v/%v-%v", e.S3Prefix, date, firstSeq, lastSeq)
+	}
 }
 
 // Emit is invoked when the buffer is full. This method emits the set of filtered records.

s3_emitter_test.go

@@ -8,12 +8,22 @@ import (
 
 func TestS3FileName(t *testing.T) {
 	d := time.Now().UTC().Format("2006/01/02")
-	e := S3Emitter{}
+	e := S3Emitter{S3Bucket: "bucket", S3Prefix: "prefix"}
 
-	expected := fmt.Sprintf("%v/a-b", d)
+	expected := fmt.Sprintf("prefix/%v/a-b", d)
 	result := e.S3FileName("a", "b")
 
 	if result != expected {
 		t.Errorf("S3FileName() = %v want %v", result, expected)
 	}
+
+	e.S3Prefix = ""
+
+	expected = fmt.Sprintf("%v/a-b", d)
+	result = e.S3FileName("a", "b")
+
+	if result != expected {
+		t.Errorf("S3FileName() = %v want %v", result, expected)
+	}
+
 }

s3_manifest_emitter.go

@@ -1,7 +1,6 @@
 package connector
 
 import (
-	"github.com/sendgridlabs/go-kinesis"
 )
 
 // An implementation of Emitter that puts event data on S3 file, and then puts the