SHOW BACKENDS
Descriptionβ
This statement is used to view the basic status information of BE nodes.
Syntaxβ
SHOW BACKENDS
Return Valueβ
| Column | Note |
|---|---|
| BackendId | The ID of the current BE. |
| Host | The IP address or host name of the current BE. |
| HeartbeatPort | The communication port of the heartbeat service of the current BE. |
| BePort | The thrift RPC communication port of the current BE. |
| HttpPort | The HTTP communication port of the current BE. |
| BrpcPort | The bRPC communication port of the current BE. |
| ArrowFlightSqlPort | The communication port of the ArrowFlight protocol of the current BE. |
| LastStartTime | The timestamp when the current BE started. |
| LastHeartbeat | The timestamp of the last successful heartbeat sent by the current BE. |
| Alive | Whether the current BE is alive. |
| SystemDecommissioned | When this value is true, it means that the current BE node is in the process of safe decommissioning. |
| TabletNum | The number of tablets stored on the current BE. |
| DataUsedCapacity | The disk space occupied by the data of the current BE. |
| TrashUsedCapacity | The disk space occupied by the data in the trash of the current BE. |
| AvailCapacity | The available disk space of the current BE. |
| TotalCapacity | The total disk space of the current BE. TotalCapacity = AvailCapacity + TrashUsedCapacity + DataUsedCapacity + Disk space occupied by other non-user data files. |
| UsedPct | The percentage of the total used disk space of the current BE. |
| MaxDiskUsedPct | The maximum percentage of the used disk space among all disks of the current BE. |
| RemoteUsedCapacity | The disk space occupied by the data uploaded to the remote storage after the hot and cold tiering function is used by the current BE. |
| Tag | The tag information of the current BE, displayed in JSON format. The saved tag information is different in different deployment modes. In the integrated storage and computing mode, the name of the current BE resource group is saved. In the decoupling storage and computing mode, some additional information is saved. |
| ErrMsg | The error message when the heartbeat of the current BE fails. |
| Version | The version information of the current BE. |
| Status | Some status information of the current BE, displayed in JSON format, including: lastSuccessReportTabletsTime, lastStreamLoadTime, isQueryDisabled, isLoadDisabled, etc. It should be noted that the information saved in different versions may vary slightly. |
| HeartbeatFailureCounter | The number of consecutive failed heartbeats of the current BE. If the number exceeds the max_backend_heartbeat_failure_tolerance_count configured by the FE Master (the default value is 1), the Alive field will be set to false. |
| NodeRole | The role of the current BE. There are two types: mix is the default role, and computation means that the current node is only used for federated analysis queries. |
Access Control Requirementsβ
The user who executes this SQL must have at least the following permissions:
| Privilege | Object | Notes |
|---|---|---|
| ADMIN_PRIV |
Usage Notesβ
If further filtering of the query results is required, the table-valued function backends() can be used. SHOW BACKENDS is equivalent to the following statement:
SELECT * FROM BACKENDS();
Examplesβ
SHOW BACKENDS;
+-----------+-----------+---------------+--------+----------+----------+--------------------+---------------------+---------------------+-------+----------------------+-----------+------------------+-------------------+---------------+---------------+---------+----------------+--------------------+--------------------------+--------+-----------------------------+------------------------------------------------------------------------------------------------------------------------------------------+-------------------------+----------+
| BackendId | Host | HeartbeatPort | BePort | HttpPort | BrpcPort | ArrowFlightSqlPort | LastStartTime | LastHeartbeat | Alive | SystemDecommissioned | TabletNum | DataUsedCapacity | TrashUsedCapacity | AvailCapacity | TotalCapacity | UsedPct | MaxDiskUsedPct | RemoteUsedCapacity | Tag | ErrMsg | Version | Status | HeartbeatFailureCounter | NodeRole |
+-----------+-----------+---------------+--------+----------+----------+--------------------+---------------------+---------------------+-------+----------------------+-----------+------------------+-------------------+---------------+---------------+---------+----------------+--------------------+--------------------------+--------+-----------------------------+------------------------------------------------------------------------------------------------------------------------------------------+-------------------------+----------+
| 10002 | 127.0.0.1 | 9050 | 9060 | 8040 | 8060 | 10040 | 2025-01-20 02:11:39 | 2025-01-21 11:52:40 | true | false | 281 | 9.690 MB | 0.000 | 10.505 GB | 71.750 GB | 85.36 % | 85.36 % | 0.000 | {"location" : "default"} | | doris-2.1.7-rc03-443e87e203 | {"lastSuccessReportTabletsTime":"2025-01-21 11:51:59","lastStreamLoadTime":1737460114345,"isQueryDisabled":false,"isLoadDisabled":false} | 0 | mix |
+-----------+-----------+---------------+--------+----------+----------+--------------------+---------------------+---------------------+-------+----------------------+-----------+------------------+-------------------+---------------+---------------+---------+----------------+--------------------+--------------------------+--------+-----------------------------+------------------------------------------------------------------------------------------------------------------------------------------+-------------------------+----------+
