Hi, In my Pinot cluster, I initially had 4 servers (A, B, C, D) with segments distributed across them. I wanted to consolidate all segments onto a single server, so I removed the tags from servers B, C, and D, and then ran a rebalance operation to allocate all segments to the remaining server (A). After rebalancing, all segments were assigned to the single server. However, the segments that were originally on the other servers appeared in ERROR state in the external view, even though their ideal state in ZooKeeper showed them as ONLINE. For example: • Ideal State:

"load_chat_messages_core_1756318894786_1758914214102_1758919671601": {
    "Server_172.18.0.6_8098": "ONLINE"
}

• External View:

"load_chat_messages_core_1756318894786_1758914214102_1758919671601": {
    "Server_172.18.0.6_8098": "ERROR"
}

To resolve this, I performed a reload and reset operation on the affected segments. After the reset, the segment state transitioned from ERROR to OFFLINE, allowing it to be properly reloaded. Setup details: • Running Pinot in Docker • Using local storage for segment files • Segment data is volume-mounted