apache/druid · warning

Told to remove non-existant segment

Error message

Told to remove non-existant segment[%s]

What it means

CoordinatorServerView.serverRemovedSegment logs a warning when it is asked to remove a segment from a server whose segmentLoadInfos map has no entry for that segment id. It is a benign consistency warning: the view state is already gone, so removal is a no-op; it does not throw for callers.

Solutions

1. Verify the historical actually announced the segment before unannouncing (check its logs for segment announce events)
2. Check inventory sync health: the HttpServerInventoryView must have processed the segmentAdd before remove
3. If seen transiently during restarts, it is safe to ignore; investigate only if persistent for the same segment/server
4. Confirm no duplicate server inventory viewers are configured pointing at the same server

// caller-side check before firing removal
if (serverView.getSegmentLoadInfo(segmentId) == null) { log.info("segment %s not tracked; skipping remove", segmentId); return; }

When it happens

Trigger: DruidServer/segment removal callbacks (segmentRemoved, removeServer) delivering a segmentRemove event for a segment never added, or already removed, on that server.

Common situations: Race between segment-announce and segment-unannounce during historical restarts, duplicate zookeeper/http inventory events, coordinator failover replaying stale segment events.

Understand the failure class

Background: Record Not Found Errors: "not found", RecordNotFound, and "was not found" — what they mean and how to fix them — this error's family across 28 libraries.

Related errors

• Asked to remove timeline entry
• Asked to add data segment that already exists!? server
• Asked to remove data segment from a data source that…
• Asked to remove data segment that doesn't exist!? server
• key must be an instance of Interval

AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/7589251051550933. Report an issue: GitHub.

Appendix: source

Thrown at server/src/main/java/org/apache/druid/client/CoordinatorServerView.java:231

      }

      segmentLoadInfo.addServer(server);

      // segment added notification
      runTimelineCallbacks(callback -> callback.segmentAdded(server, segment));
    }
  }

  private void serverRemovedSegment(DruidServerMetadata server, DataSegment segment)
  {
    SegmentId segmentId = segment.getId();

    synchronized (lock) {
      log.debug("Removing segment[%s] from server[%s].", segmentId, server);

      final SegmentLoadInfo segmentLoadInfo = segmentLoadInfos.get(segmentId);
      if (segmentLoadInfo == null) {
        log.warn("Told to remove non-existant segment[%s]", segmentId);
        return;
      }

      if (segmentLoadInfo.removeServer(server)) {
        // server segment removed notification
        runTimelineCallbacks(callback -> callback.serverSegmentRemoved(server, segment));
      }

      if (segmentLoadInfo.isEmpty()) {
        VersionedIntervalTimeline<String, SegmentLoadInfo> timeline = timelines.get(segment.getDataSource());
        segmentLoadInfos.remove(segmentId);

        final PartitionChunk<SegmentLoadInfo> removedPartition = timeline.remove(
            segment.getInterval(), segment.getVersion(), segment.getShardSpec().createChunk(
                new SegmentLoadInfo(
                    segment
                )
            )

View on GitHub (pinned to 9b90983fd2)