Recover managed process log sessions

spool/log_spool_test.go

@@ -157,6 +157,37 @@ func TestLogSpoolFlushPrioritizesNewerProcessSessions(t *testing.T) {
 	}
 }
 
+func TestLogSpoolSequenceGapResetsWatermarkToPlatformLatest(t *testing.T) {
+	logSpool, err := NewLogSpool(t.TempDir())
+	if err != nil {
+		t.Fatalf("new log spool: %v", err)
+	}
+	if err := logSpool.Enqueue(validSpoolLogBatch(10, 10)); err != nil {
+		t.Fatalf("enqueue gapped batch: %v", err)
+	}
+	if err := logSpool.Enqueue(validSpoolLogBatch(11, 11)); err != nil {
+		t.Fatalf("enqueue later gapped batch: %v", err)
+	}
+	client := &recoveringSequenceGapLogBatchClient{latestSeq: 5}
+	flushed, err := logSpool.Flush(context.Background(), client)
+	if err != nil || flushed != 2 {
+		t.Fatalf("recover sequence gap: flushed=%d err=%v", flushed, err)
+	}
+	if len(client.progressBatches) != 1 || client.progressBatches[0].FirstSeq != 10 {
+		t.Fatalf("expected one progress recovery from gapped batch, got %+v", client.progressBatches)
+	}
+	pending, err := logSpool.Pending()
+	if err != nil || len(pending) != 0 {
+		t.Fatalf("expected gapped batches rejected, pending=%+v err=%v", pending, err)
+	}
+	checksum := func(entries []protocol.LogEntry) (string, error) { return fmt.Sprintf("sha256:%d", len(entries)), nil }
+	next := validSpoolLogBatch(0, 0)
+	sequence, appended, err := logSpool.EnqueueNextAggregated(context.Background(), next, nil, nil, checksum)
+	if err != nil || !appended || sequence != 6 {
+		t.Fatalf("expected next sequence to resume after platform latest, sequence=%d appended=%t err=%v", sequence, appended, err)
+	}
+}
+
 func TestLogSpoolRestoresPendingAllocationWithoutWatermark(t *testing.T) {
 	root := t.TempDir()
 	first, err := NewLogSpool(root)
@@ -298,9 +329,23 @@ func (client *blockingLogBatchClient) IngestLogBatch(_ context.Context, batch pr
 type permanentRejectLogBatchClient struct{}
 
 func (permanentRejectLogBatchClient) IngestLogBatch(context.Context, protocol.LogBatchIngestRequest) (protocol.LogBatchIngestResponse, error) {
+	return protocol.LogBatchIngestResponse{}, PermanentLogBatchRejection("platform_not_found", nil)
+}
+
+type recoveringSequenceGapLogBatchClient struct {
+	latestSeq       uint64
+	progressBatches []protocol.LogBatchIngestRequest
+}
+
+func (client *recoveringSequenceGapLogBatchClient) IngestLogBatch(context.Context, protocol.LogBatchIngestRequest) (protocol.LogBatchIngestResponse, error) {
 	return protocol.LogBatchIngestResponse{}, PermanentLogBatchRejection("platform_sequence_gap", nil)
 }
 
+func (client *recoveringSequenceGapLogBatchClient) LogStreamLatestSeq(_ context.Context, batch protocol.LogBatchIngestRequest) (uint64, error) {
+	client.progressBatches = append(client.progressBatches, batch)
+	return client.latestSeq, nil
+}
+
 type recordingLogBatchClient struct {
 	batches []protocol.LogBatchIngestRequest
 }