Add todos back

pinot-core/src/main/java/org/apache/pinot/core/data/manager/realtime/IngestionDelayTracker.java

@@ -95,15 +95,14 @@ public class IngestionDelayTracker {
   public static final int MAX_OFFSET_FETCH_WAIT_TIME_MS = 5000;
 
   private static class IngestionInfo {
+    final StreamMetadataProvider _streamMetadataProvider;
     volatile Long _ingestionTimeMs;
     volatile Long _firstStreamIngestionTimeMs;
     volatile StreamPartitionMsgOffset _currentOffset;
     volatile StreamPartitionMsgOffset _latestOffset;
-    final StreamMetadataProvider _streamMetadataProvider;
 
-    IngestionInfo(@Nullable Long ingestionTimeMs, @Nullable Long firstStreamIngestionTimeMs,
-        @Nullable StreamPartitionMsgOffset currentOffset,
-        @Nullable StreamMetadataProvider streamMetadataProvider) {
+    IngestionInfo(Long ingestionTimeMs, Long firstStreamIngestionTimeMs, StreamPartitionMsgOffset currentOffset,
+        StreamMetadataProvider streamMetadataProvider) {
       _ingestionTimeMs = ingestionTimeMs;
       _firstStreamIngestionTimeMs = firstStreamIngestionTimeMs;
       _currentOffset = currentOffset;
@@ -149,11 +148,14 @@ void updateIngestionTimes(long ingestionTimeMs, long firstStreamIngestionTimeMs)
   // We mark partitions that go from CONSUMING to ONLINE in _partitionsMarkedForVerification: if they do not
   // go back to CONSUMING in some period of time, we verify whether they are still hosted in this server by reading
   // ideal state. This is done with the goal of minimizing reading ideal state for efficiency reasons.
+  // TODO: Consider removing this mechanism after releasing 1.2.0, and use {@link #stopTrackingPartitionIngestionDelay}
+  // instead
   private final Map<Integer, Long> _partitionsMarkedForVerification = new ConcurrentHashMap<>();
 
   private final Cache<String, Boolean> _segmentsToIgnore =
       CacheBuilder.newBuilder().expireAfterAccess(IGNORED_SEGMENT_CACHE_TIME_MINUTES, TimeUnit.MINUTES).build();
 
+  // TODO: Make thread pool a server/cluster level config
   // ScheduledExecutorService to check partitions that are inactive against ideal state.
   private final ScheduledExecutorService _scheduledExecutor = Executors.newScheduledThreadPool(2);