Fixed case checkpoints would only occur on shutdown. The archive consumer fell victim of this bug.

batchconsumer/batchermanager.go

@@ -114,7 +114,7 @@ func (b *batcherManager) sendBatch(batcher *batcher, tag string) {
 }
 
 func (b *batcherManager) sendCheckpoint(
-	tag string, lastIgnoredPair kcl.SequencePair, batchers map[string]*batcher,
+	tag string, lastIgnoredPair, lastProcessedPair kcl.SequencePair, batchers map[string]*batcher,
 ) {
 	smallest := lastIgnoredPair
 
@@ -133,9 +133,10 @@ func (b *batcherManager) sendCheckpoint(
 		}
 	}
 
-	if !smallest.IsNil() {
-		b.chkpntManager.Checkpoint(smallest)
+	if smallest.IsNil() { // This can occur when all messages in a stream go into one batch
+		smallest = lastProcessedPair
 	}
+	b.chkpntManager.Checkpoint(smallest)
 }
 
 // startMessageDistributer starts a go-routine that routes messages to batches.  It's in uses a
@@ -164,7 +165,7 @@ func (b *batcherManager) startMessageHandler(
 				for tag, batcher := range batchers {
 					if b.batchInterval <= time.Now().Sub(batcher.LastUpdated) {
 						b.sendBatch(batcher, tag)
-						b.sendCheckpoint(tag, lastIgnoredPair, batchers)
+						b.sendCheckpoint(tag, lastIgnoredPair, lastProcessedPair, batchers)
 						batcher.Clear()
 					}
 				}
@@ -179,7 +180,7 @@ func (b *batcherManager) startMessageHandler(
 				err := batcher.AddMessage(tmp.msg, tmp.pair)
 				if err == ErrBatchFull {
 					b.sendBatch(batcher, tmp.tag)
-					b.sendCheckpoint(tmp.tag, lastIgnoredPair, batchers)
+					b.sendCheckpoint(tmp.tag, lastIgnoredPair, lastProcessedPair, batchers)
 
 					batcher.AddMessage(tmp.msg, tmp.pair)
 				} else if err != nil {

batchconsumer/writer_test.go

@@ -162,6 +162,53 @@ func TestProcessRecordsIgnoredMessages(t *testing.T) {
 	assert.Contains(mockcheckpointer.recievedSequences, "4")
 }
 
+func TestProcessRecordsSingleBatchBasic(t *testing.T) {
+	assert := assert.New(t)
+
+	mocklog := logger.New("testing")
+	mockconfig := withDefaults(Config{
+		BatchCount:     2,
+		CheckpointFreq: 1, // Don't throttle checks points
+	})
+	mockcheckpointer := NewMockCheckpointer(5 * time.Second)
+	mocksender := NewMsgAsTagSender()
+
+	wrt := NewBatchedWriter(mockconfig, mocksender, mocklog)
+	wrt.Initialize("test-shard", mockcheckpointer)
+
+	err := wrt.ProcessRecords([]kcl.Record{
+		kcl.Record{SequenceNumber: "1", Data: encode("tag1")},
+		kcl.Record{SequenceNumber: "2", Data: encode("tag1")},
+		kcl.Record{SequenceNumber: "3", Data: encode("tag1")},
+		kcl.Record{SequenceNumber: "4", Data: encode("tag1")},
+	})
+	assert.NoError(err)
+	err = wrt.ProcessRecords([]kcl.Record{
+		kcl.Record{SequenceNumber: "5", Data: encode("tag1")},
+		kcl.Record{SequenceNumber: "6", Data: encode("tag1")},
+		kcl.Record{SequenceNumber: "7", Data: encode("tag1")},
+		kcl.Record{SequenceNumber: "8", Data: encode("tag1")},
+	})
+	assert.NoError(err)
+
+	err = wrt.Shutdown("TERMINATE")
+	assert.NoError(err)
+
+	err = mockcheckpointer.wait()
+	assert.NoError(err)
+
+	mocksender.Shutdown()
+
+	assert.Contains(mocksender.batches, "tag1")
+	assert.Equal(4, len(mocksender.batches["tag1"]))
+
+	assert.Contains(mockcheckpointer.recievedSequences, "2")
+	assert.Contains(mockcheckpointer.recievedSequences, "4")
+	assert.Contains(mockcheckpointer.recievedSequences, "6")
+	assert.Contains(mockcheckpointer.recievedSequences, "8")
+
+}
+
 func TestProcessRecordsMutliBatchBasic(t *testing.T) {
 	assert := assert.New(t)