kgo-repeater: add additional error handling for txn to inc stability

Author: ballard26

pkg/worker/repeater/repeater_worker.go

@@ -21,6 +21,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/binary"
+	"errors"
 	"fmt"
 	"math/rand"
 	_ "net/http/pprof"
@@ -29,6 +30,7 @@ import (
 
 	"github.com/google/uuid"
 	log "github.com/sirupsen/logrus"
+	"github.com/twmb/franz-go/pkg/kerr"
 	"github.com/twmb/franz-go/pkg/kgo"
 
 	"github.com/redpanda-data/kgo-verifier/pkg/util"
@@ -381,6 +383,14 @@ loop:
 
 		if v.transactionsEnabled {
 			if _, err := v.transactionSTM.BeforeMessageSent(); err != nil {
+				if errors.Is(err, kerr.OperationNotAttempted) {
+					// Try to recover this producer by rolling back the transaction.
+					err = v.transactionSTM.TryRollbackTransaction()
+					if err == nil {
+						continue
+					}
+				}
+
 				log.Errorf("Produce error; transaction failure: %v", err)
 				break loop
 			}
@@ -430,6 +440,18 @@ loop:
 			// consumer needs logic to handle the unexpected token
 			log.Debugf("Produce %s acked %d on partition %d offset %d", v.config.workerCfg.Name, token, r.Partition, r.Offset)
 			if err != nil {
+				// For transactions an INVALID_TXN_STATE is encountered often while restarting nodes
+				// Try to be tolerant of this error.
+				// TODO: Is there a way to avoid this?
+				if v.transactionsEnabled && (errors.Is(err, kerr.OperationNotAttempted) || errors.Is(err, kerr.InvalidTxnState)) {
+					err = v.transactionSTM.TryRollbackTransaction()
+					if err == nil {
+						v.pending <- token
+						ackWait.Done()
+						return
+					}
+				}
+
 				// On produce error, we drop the token: we rely on producer errors
 				// being rare and/or a background Tuner re-injecting fresh tokens
 				log.Errorf("Produce %s error, dropped token %d: %v", v.config.workerCfg.Name, token, err)
@@ -440,6 +462,7 @@ loop:
 				v.globalStats.Ack_latency.Update(ackLatency.Microseconds())
 				v.totalProduced += 1
 			}
+
 			ackWait.Done()
 		}
 

pkg/worker/transaction_stm.go

@@ -64,6 +64,25 @@ func (t *TransactionSTM) TryEndTransaction() error {
 	return nil
 }
 
+// If an OPERATION_NOT_ATTEMPTED error occurs on the producer it
+// can sometimes recover by rolling back the current transaction.
+func (t *TransactionSTM) TryRollbackTransaction() error {
+	if err := t.client.AbortBufferedRecords(t.ctx); err != nil {
+		log.Errorf("Error aborting buffered records: %v", err) 
+        return err
+	}
+	if err := t.client.EndTransaction(t.ctx, kgo.TryAbort); err != nil {
+		log.Errorf("Error rolling back transaction: %v", err)
+		return err
+	}
+
+	log.Debugf("Rolled back a transaction; currentMgsProduced = %d aborted = %t", t.currentMgsProduced, t.abortedTransaction)
+
+	t.currentMgsProduced = 0
+	t.activeTransaction = false
+	return nil
+}
+
 // Returns true iff a new transaction was started and/or a current
 // transaction ended. This is to notify any producers that control
 // markers will be added to a partition's log.