| --- |
| { |
| "title": "SHOW-BACKENDS", |
| "language": "en" |
| } |
| --- |
| |
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| |
| ## SHOW-BACKENDS |
| |
| ### Name |
| |
| SHOW BACKENDS |
| |
| ### Description |
| |
| This statement is used to view the BE nodes in the cluster |
| |
| ```sql |
| SHOW BACKENDS; |
| ``` |
| |
| illustrate: |
| |
| 1. LastStartTime indicates the last BE start time. |
| 2. LastHeartbeat indicates the last heartbeat. |
| 3. Alive indicates whether the node is alive or not. |
| 4. If SystemDecommissioned is true, it means that the node is being safely decommissioned. |
| 5. If ClusterDecommissioned is true, it means that the node is going offline in the current cluster. |
| 6. TabletNum represents the number of shards on the node. |
| 7. DataUsedCapacity Indicates the space occupied by the actual user data. |
| 8. AvailCapacity Indicates the available space on the disk. |
| 9. TotalCapacity represents the total disk space. TotalCapacity = AvailCapacity + DataUsedCapacity + other non-user data files occupy space. |
| 10. UsedPct Indicates the percentage of disk used. |
| 11. ErrMsg is used to display the error message when the heartbeat fails. |
| 12. Status is used to display some status information of BE in JSON format, including the time information of the last time BE reported its tablet. |
| 13. HeartbeatFailureCounter: The current number of heartbeats that have failed consecutively. If the number exceeds the `max_backend_heartbeat_failure_tolerance_count` configuration, the isAlive will be set to false. |
| 14. NodeRole is used to display the role of Backend node. Now there are two roles: mix and computation. Mix node represent the origin Backend node and computation Node represent the compute only node. |
| |
| ### Example |
| |
| ### Keywords |
| |
| SHOW, BACKENDS |
| |
| ### Best Practice |
| |