dosubot[bot] commented on issue #3150: URL: https://github.com/apache/hugegraph/issues/3150#issuecomment-5249829805
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When you `POST /v1/store/{storeId}` with `Tombstone` state, PD internally calls `storeTurnoff()` which removes the Store's shards from each shard group and then calls `reallocShards()` to redistribute replicas to healthy active Stores [[1]](https://github.com/apache/hugegraph/blob/9126c80e414c073b60fc074361b211cfb409e0eb/hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/StoreNodeService.java#L271-L341). However, migration isn't instantaneous — there are two automatic mechanisms that complete the process: 1. **Replica repair patrol** (`patrolPartitions()`) runs every **60 seconds** on the PD leader. It detects tombstoned Stores and repairs shard groups whose replica count is below the configured value [[2]](https://github.com/apache/hugegraph/blob/9126c80e414c073b60fc074361b211cfb409e0eb/hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/TaskScheduleService.java#L231-L266). 2. **Cluster-wide load balancing** (`balancePartitionShard()`) runs with a **30-minute delay** after a Store is removed, redistributing shards evenly across remaining active Stores [[3]](https://github.com/apache/hugegraph/blob/9126c80e414c073b60fc074361b211cfb409e0eb/hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/TaskScheduleService.java#L337-L449). If you checked `/v1/partitions` immediately after setting Tombstone, the migration may not have completed yet. **Wait a few minutes and check again** — the shard groups should update as the patrol task runs. One prerequisite: PD validates that removing the Store won't drop the active Store count below `minStoreCount`. If it would, the Tombstone transition fails with `LESS_ACTIVE_STORE` [[4]](https://github.com/apache/hugegraph/blob/9126c80e414c073b60fc074361b211cfb409e0eb/hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/StoreNodeService.java#L271-L279). Check the PD response and logs to confirm it actually accepted the state change. **Recommended recovery workflow for permanent data loss:** 1. **Set the failed Store to Tombstone:** ``` POST /v1/store/{storeId} Body: {"storeState": "Tombstone"} ``` 2. **Monitor migration progress** — poll these endpoints over the next few minutes: ``` GET /v1/partitions GET /v1/shardGroups ``` Verify that shards previously on the failed Store are reassigned to other Stores. 3. **(Optional) Trigger leader rebalancing:** ``` GET /v1/balanceLeaders ``` This is the only manual rebalancing endpoint currently exposed [[5]](https://github.com/apache/hugegraph/blob/9126c80e414c073b60fc074361b211cfb409e0eb/hugegraph-pd/hg-pd-service/src/main/java/org/apache/hugegraph/pd/rest/StoreAPI.java#L148-L151). 4. **Reinitialize the physical node as a new Store.** A tombstoned Store ID is permanently decommissioned — it cannot re-register. You must wipe the Store's data directory and restart it so it registers with a fresh Store ID [[6]](https://github.com/apache/hugegraph/blob/9126c80e414c073b60fc074361b211cfb409e0eb/hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/StoreNodeService.java#L149-L158). **Important notes:** - **`store.max-down-time` is not implemented in runtime code.** Despite being documented and configurable (default 86400s / 24h), no PD code actually uses this timeout to trigger automatic recovery [[7]](https://github.com/apache/hugegraph/blob/9126c80e414c073b60fc074361b211cfb409e0eb/hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/config/PDConfig.java#L166-L177) [[8]](https://github.com/apache/hugegraph/blob/9126c80e414c073b60fc074361b211cfb409e0eb/hugegraph-pd/hg-pd-service/src/main/resources/application.yml#L67-L71). Replica migration is only triggered by explicit Store state changes (OFFLINE → Tombstone), not by elapsed downtime. This is a known gap between documentation and implementation. - **There is no REST API for manual partition/shard migration.** The internal methods `movePartitionsShard()` and `reallocPartitionShards()` exist in `PartitionService` [[9]](https://github.com/apache/hugegraph/blob/9126c80e414c073b60fc074361b211cfb409e0eb/hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/PartitionService.java#L578-L613) but are not exposed via REST endpoints. Migration happens automatically through Store state changes. - **Alternative: use the `Exiting` state** for more graceful decommissioning. Setting a Store to `Exiting` triggers the same shard reallocation, but the Store remains in that state until it reports zero partitions via heartbeat, at which point PD automatically transitions it to Tombstone [[10]](https://github.com/apache/hugegraph/blob/9126c80e414c073b60fc074361b211cfb409e0eb/hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/StoreNodeService.java#L739-L765). This is better suited for planned maintenance. If you're still seeing shards assigned to the Tombstone Store after several minutes, please share the PD leader logs and the exact response from `POST /v1/store/{storeId}` — it's possible the transition was rejected due to a `minStoreCount` constraint or the PD node you're hitting isn't the leader. <!-- Dosu Comment Footer --> *To reply, just mention [@dosu](<https://go.dosu.dev/dosubot?utm_source=github&utm_medium=bot-comment&utm_campaign=github-comment-footer-20260415&utm_content=reply-with-mention&utm_term=apache%2Fhugegraph>).* --- Share context across your team and agents. Try [Dosu](https://dosu.dev?utm_source=github&utm_medium=bot-comment&utm_campaign=github-comment-footer-20260415&utm_content=knowledge-infrastructure-tagline&utm_term=apache%2Fhugegraph). 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