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 name of the current BE resource group 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 |
+-----------+-----------+---------------+--------+----------+----------+--------------------+---------------------+---------------------+-------+----------------------+-----------+------------------+-------------------+---------------+---------------+---------+----------------+--------------------+--------------------------+--------+-----------------------------+------------------------------------------------------------------------------------------------------------------------------------------+-------------------------+----------+
