Make it possible to configure maximum retry count when

executing transactions.

crdb/common.go

@@ -62,8 +62,7 @@ func ExecuteInTx(ctx context.Context, tx Tx, fn func() error) (err error) {
 		return err
 	}
 
-	// TODO(rafi): make the maxRetryCount configurable. Maybe pass it in the context?)
-	const maxRetries = 50
+	maxRetries := numRetriesFromContext(ctx)
 	retryCount := 0
 	for {
 		releaseFailed := false
@@ -90,7 +89,7 @@ func ExecuteInTx(ctx context.Context, tx Tx, fn func() error) (err error) {
 		}
 
 		retryCount++
-		if retryCount > maxRetries {
+		if maxRetries > 0 && retryCount > maxRetries {
 			return newMaxRetriesExceededError(err, maxRetries)
 		}
 	}

crdb/tx.go

@@ -102,6 +102,26 @@ func Execute(fn func() error) (err error) {
 	}
 }
 
+type txConfigKey struct {}
+
+// WithMaxRetries configures context so that ExecuteTx retries tx specified
+// number of times when encountering retryable errors.
+// Setting retries to 0 will retry indefinitely.
+func WithMaxRetries(ctx context.Context, retries int) context.Context {
+	return context.WithValue(ctx, txConfigKey{}, retries)
+}
+
+const defaultRetries = 50
+
+func numRetriesFromContext(ctx context.Context) int {
+	if v := ctx.Value(txConfigKey{}); v != nil {
+		if retries, ok := v.(int); ok && retries >= 0 {
+			return retries
+		}
+	}
+	return defaultRetries
+}
+
 // ExecuteTx runs fn inside a transaction and retries it as needed. On
 // non-retryable failures, the transaction is aborted and rolled back; on
 // success, the transaction is committed.

crdb/tx_test.go

@@ -35,6 +35,19 @@ func TestExecuteTx(t *testing.T) {
 	}
 }
 
+// TestConfigureRetries verifies that the number of retries can be specified
+// via context.
+func TestConfigureRetries(t *testing.T) {
+	ctx := context.Background()
+	if numRetriesFromContext(ctx) != defaultRetries {
+		t.Fatal("expect default number of retries")
+	}
+	ctx = WithMaxRetries(context.Background(), 123 + defaultRetries)
+	if numRetriesFromContext(ctx) != defaultRetries + 123 {
+		t.Fatal("expected default+123 retires")
+	}
+}
+
 type stdlibWriteSkewTest struct {
 	db *sql.DB
 }