Serverless backfilling

Overview

Serverless backfilling in RisingWave Cloud runs materialized view backfill jobs on dedicated backfiller resources instead of your main streaming compute nodes. When a serverless backfill job starts, RisingWave Cloud provisions a temporary resource group for that job by using the configured Backfiller SKU and Replicas as template values. This page focuses on enabling and sizing the Cloud resources. For SQL usage, session variables, WITH clause options, limitations, and monitoring, see Serverless backfill.

Configure serverless backfilling

Serverless backfilling settings are separate from the main cluster setup. To access them:

Open your project in the RisingWave Cloud console.
Select Resources in the left sidebar.
Click the Backfillings tab.
Toggle Serverless backfilling on, then configure the settings below.

The following screenshot shows the Backfillings tab in the Resources page:

Backfiller SKU

The Backfiller SKU defines the compute size used when RisingWave Cloud provisions the temporary resource group for a serverless backfill job. Choose a larger SKU for faster backfill throughput on large upstream tables, or a smaller SKU to minimize cost.

Replicas

Replicas sets the default replica count used when RisingWave Cloud provisions the temporary resource group for a serverless backfill job:

Increase the replica count if you expect more concurrent backfill work or need higher throughput.
Use a smaller replica count if you want to keep backfill resource usage lower.

Scheduling behavior

RisingWave Cloud manages the backfill resources automatically:

When a new serverless backfill job is submitted, RisingWave Cloud creates a dynamic resource group for that job by using the configured Backfiller SKU and Replicas.
The backfill job runs in that dynamic resource group during materialized view creation.
After the materialized view is created successfully, the materialized view is migrated back to the default resource group.

Use serverless backfilling in SQL

After enabling serverless backfilling in the Cloud console, use either SET enable_serverless_backfill = true or WITH (cloud.serverless_backfill_enabled = true) when creating a materialized view. See Serverless backfill for:

SQL examples
Session-variable and per-statement configuration
resource_group limitations
Monitoring and progress tracking