ALTER-SYSTEM-ADD-BACKEND

Description

The ADD BACKEND command is used to add one or more backend nodes to a Doris OLAP database cluster. This command allows administrators to specify the host and port of the new backend nodes, along with optional properties that configure their behavior.

Syntax

-- Add nodes (add this method if you do not use the multi-tenancy function)
   ALTER SYSTEM ADD BACKEND "host:heartbeat_port"[,"host:heartbeat_port"...] [PROPERTIES ("key"="value", ...)];

Parameters

• host can be a hostname or an ip address of the backend node while heartbeat_port is the heartbeat port of the node

• PROPERTIES ("key"="value", ...): (Optional) A set of key-value pairs that define additional properties for the backend nodes. These properties can be used to customize the configuration of the backends being added. Available properties include:

  • tag.location: Specifies the resource group where the backend node belongs. For example, PROPERTIES ("tag.location" = "groupb").
  • tag.compute_group_name: Specifies the resource group where the backend node belongs. For example, PROPERTIES ("tag.compute_group_name" = "groupb").

Example

1. Adding Backends Without Additional Properties

   ALTER SYSTEM ADD BACKEND "host1:9050,host2:9050";

   This command adds two backend nodes to the cluster:

   • host1 with port 9050
   • host2 with port 9050

   No additional properties are specified, so the default settings will apply to these backends.

2. Adding Backends With Resource Group

   ALTER SYSTEM ADD BACKEND "host3:9050" PROPERTIES ("tag.location" = "groupb");

   This command adds a single backend node (host3 with port 9050) to the cluster in resource group groupb:

3. Adding Backends With Compute Group

   ALTER SYSTEM ADD BACKEND "host3:9050" PROPERTIES ("tag.compute_group_name" = "groupb");

   This command adds a single backend node (host3 with port 9050) to the cluster in compute group groupb:

Keywords

ALTER, SYSTEM, ADD, BACKEND, PROPERTIES

Best Practice