Expanding a Standalone Databend

Expanding a Standalone Databend

If you already have a standalone Databend, you can expand it by adding one or more query nodes to obtain more powerful computing capability.

In this topic, we will add a new Query node to an existing standalone Databend.

Deploying a Standalone Databend

Follow Deploying with Self-Hosted Object Storage to deploy a local standalone Databend with MinIO.

Deploying a New Query Node

1. Make a copy of the file databend-query-node.toml in the folder /usr/local/databend/etc, paste it to the same folder with a name databend-query-node2.toml.

2. Open the file databend-query-node2.toml, modify the values for the parameters as below:

# For admin RESET API.
admin_api_address = "127.0.0.1:8082"

# Cluster flight RPC.
flight_api_address = "127.0.0.1:9092"

tip

Keep the same cluster ID. When you set up a new Query node for a cluster, make sure all the cluster IDs are the same across the nodes. A Query node uses this ID to decide which cluster to join and registers to the corresponding Meta node.

3. Open a terminal window and navigate to the folder /usr/local/databend/bin.

4. Run the following command to start the Query node:

./databend-query -c ./databend-query-node2.toml 2>&1 > query.node2.log&

5. Run the following command to check if the new node was started successfully:

curl -I  http://127.0.0.1:8082/v1/health

6. Check the cluster information:

mysql -h127.0.0.1 -uroot -P3308
SELECT * FROM system.clusters
+------------------------+-----------+------+
| name                   | host      | port |
+------------------------+-----------+------+
| QXyxUbieMYMV6OGrjoDKL6 | 127.0.0.1 | 9092 |
| Y1lJiseTjCLwpVRYItQ2f3 | 127.0.0.1 | 9091 |
+------------------------+-----------+------+