The race condition that TableDataManager is removed during segment download because of incorrect segment count.

Current code does the followings:

1. tableDataManager uses segmentDataManagerMap to track the segments. tableDataManager is created and initialized when adding the first segment to the server, and shutdown if the last segment is removed.
2. The tmp directory for temporarily storing new downloaded segments will be removed and recreated as part of tableDataManager initialization.
3. When adding a new segment to server, the server will download the segment first and update the segmentDataManagerMap after.

This can cause two issues:

1. If the last segment is removed from segmentDataManagerMap during new segment download time and before updating segmentDataManagerMap, the tableDataManager will be shutdown, and the new segment will become unreachable. We will have partial query results with SERVER_SEGMENT_MISSING_ERROR.
2. If tableDataManager is initialized during the segment download in scenario 1, the downloaded tar file will be removed. The server will take it as download failure, and the segment will stay in ERROR state until fixed manually by restarting the server. We have observed this issue recently after #7961 was merged.

[Jackie-Jiang]

After some offline discussion, one way to solve this issue is to add a DELETE message, and only remove the tableDataManager when the table is deleted

[npawar]

has this been resolved? can the issue be closed?