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Version: Latest-3.3

SHOW BACKENDS

Description

Shows the information of all BE nodes in the cluster.

tip

Only users with the SYSTEM-level OPERATE privilege or the cluster_admin role can perform this operation.

Syntax

SHOW BACKENDS

Return

+-----------+-----------+---------------+--------+----------+----------+---------------------+---------------------+-------+----------------------+-----------------------+-----------+------------------+---------------+---------------+---------+----------------+--------+--------------------+--------------------------------------------------------+-------------------+-------------+----------+-------------------+------------+------------+------------------+----------+
| BackendId | IP | HeartbeatPort | BePort | HttpPort | BrpcPort | LastStartTime | LastHeartbeat | Alive | SystemDecommissioned | ClusterDecommissioned | TabletNum | DataUsedCapacity | AvailCapacity | TotalCapacity | UsedPct | MaxDiskUsedPct | ErrMsg | Version | Status | DataTotalCapacity | DataUsedPct | CpuCores | NumRunningQueries | MemUsedPct | CpuUsedPct | DataCacheMetrics | Location |
+-----------+-----------+---------------+--------+----------+----------+---------------------+---------------------+-------+----------------------+-----------------------+-----------+------------------+---------------+---------------+---------+----------------+--------+--------------------+--------------------------------------------------------+-------------------+-------------+----------+-------------------+------------+------------+------------------+----------+
ReturnDescription
BackendIdThe ID of the BE node.
IPThe IP address of the BE node.
HeartbeatPortThe heartbeat port of the BE node. It is used to receive heartbeats from the FE node.
BePortThrift server port of the BE node. It is used to receive requests from the FE node.
HttpPortHTTP server port of the BE node. It is used to access the BE node via web page.
BrpcPortbRPC port of the BE node. It is used for communication across BE nodes.
LastStartTimeThe last time when the BE node is started.
LastHeartbeatThe last time when the FE node sends a heartbeat and the BE responds.
AliveWhether the BE node is alive or not.
  • true: the BE node is alive.
  • false: the BE node is not alive.
SystemDecommissionedWhether the BE node is decommissioned or not. Before it is decommissioned, the BE node migrates the data to other BE nodes. Data loading and queries are not affected during migration.
  • true: the cluster has marked the BE node as decommissioned. The data could be successfully migrated or migrating.
  • false: the BE node is running.
ClusterDecommissionedThis parameter is used for system compatibility.
TabletNumThe number of tablets on the BE node.
DataUsedCapacityThe storage capacity occupied by the data file.
AvailCapacityAvailable storage capacity in the BE node.
TotalCapacityThe total storage capacity. It is equivalent to DataUsedCapacity + AvailCapacity + Storage capacity occupied by the non-data files.
UsedPctThe percentage of the used storage capacity.
MaxDiskUsedPctIf a BE node has multiple directories to store data, this parameter shows the maximum percentage of the used storage capacity among all directories.
ErrMsgThe error message returned when the BE node fails to receive the heartbeat from the FE node.
VersionThe StarRocks version of cluster.
StatusThe last time when the BE node reports the tablet number to the FE node. Displayed in JSON format.
DataTotalCapacityIt is equivalent to DataUsedCapacity + AvailCapacity. It indicates the sum of the storage capacity occupied by the data file and the available storage capacity in the BE node.
DataUsedPctIt is equivalent to DataUsedCapacity/DataTotalCapacity. It indicates the proportion of the storage capacity occupied by the data file to the sum of the data-occupied storage capacity and the available storage capacity.
CpuCoresThe number of CPU cores in the BE node.
NumRunningQueriesThe number of running queries on the BE node.
MemUsedPctThe percentage of used memory.
CpuUsedPctThe percentage of used CPU cores.
DataCacheMetricsThe status of Data Cache:
  • Disabled: Disabled
  • Normal: Normal
  • Abnormal: Abnormal
  • Updating: Data Cache is being updating, for example, scaling.
LocationThe label of the BE node. For more information, see Add labels on BEs.

Example

View the information of all BE nodes in the cluster.

SHOW BACKENDS;

+-----------+---------+---------------+--------+----------+----------+---------------------+---------------------+-------+----------------------+-----------------------+-----------+------------------+---------------+---------------+---------+----------------+--------+----------------------+--------------------------------------------------------+-------------------+-------------+----------+
| BackendId | IP | HeartbeatPort | BePort | HttpPort | BrpcPort | LastStartTime | LastHeartbeat | Alive | SystemDecommissioned | ClusterDecommissioned | TabletNum | DataUsedCapacity | AvailCapacity | TotalCapacity | UsedPct | MaxDiskUsedPct | ErrMsg | Version | Status | DataTotalCapacity | DataUsedPct | CpuCores |
+-----------+---------+---------------+--------+----------+----------+---------------------+---------------------+-------+----------------------+-----------------------+-----------+------------------+---------------+---------------+---------+----------------+--------+----------------------+--------------------------------------------------------+-------------------+-------------+----------+
| 10002 | x.x.x.x | 9254 | 9260 | 8238 | 8260 | 2022-09-08 14:37:10 | 2022-09-08 15:14:21 | true | false | false | 21753 | 25.122 GB | 1.088 TB | 1.968 TB | 44.72 % | 44.72 % | | MAIN-RELEASE-d094052 | {"lastSuccessReportTabletsTime":"2022-09-08 15:14:13"} | 1.113 TB | 2.20 % | 16 |
| 10003 | x.x.x.x | 9254 | 9260 | 8238 | 8260 | 2022-09-08 14:37:20 | 2022-09-08 15:14:21 | true | false | false | 21754 | 25.121 GB | 1.169 TB | 1.968 TB | 40.61 % | 40.61 % | | MAIN-RELEASE-d094052 | {"lastSuccessReportTabletsTime":"2022-09-08 15:14:22"} | 1.194 TB | 2.06 % | 16 |
| 10004 | x.x.x.x | 9254 | 9260 | 8238 | 8260 | 2022-09-08 14:37:39 | 2022-09-08 15:14:21 | true | false | false | 21754 | 25.112 GB | 1.172 TB | 1.968 TB | 40.46 % | 40.46 % | | MAIN-RELEASE-d094052 | {"lastSuccessReportTabletsTime":"2022-09-08 15:13:42"} | 1.197 TB | 2.05 % | 16 |
+-----------+---------+---------------+--------+----------+----------+---------------------+---------------------+-------+----------------------+-----------------------+-----------+------------------+---------------+---------------+---------+----------------+--------+----------------------+--------------------------------------------------------+-------------------+-------------+----------+