reservation for BQ Materialized view refresh jobs

[keshavhsk]

is it possible to set a custom reservation(other than project reservation) ex: if i have a MV in project A , is it possible to make use of slots from Project from B for this MV refresh jobs?

[ms4446]

Yes, it is possible to utilize BigQuery slots from Project B to refresh a materialized view (MV) in Project A, as long as the appropriate permissions and configurations are in place. Here's a possible solution:

Step 1: Create a Reservation in Project B

• Plan Ahead: Analyze the computational requirements of the MV refresh jobs in Project A, as well as the typical workload in Project B, to purchase the right number of slots.
• Create a Clear Reservation: Name the reservation descriptively (e.g., project-b-shared) to aid in tracking and management.

Step 2: Grant IAM Permissions

• Security First: Follow the principle of least privilege. Grant access only to necessary service accounts or users from Project A that will be executing the MV refresh jobs.
• Granting the Right Role: In the IAM & Admin section of Project B, assign the roles/bigquery.resourceUser role to the relevant entities in Project A. This authorizes them to use the shared reservation.

Step 3: Configure Jobs in Project A

• Know Your Tools: The way to specify the reservation ID will depend on whether you schedule MV refreshes through the BigQuery UI, the API, or client libraries. Find instructions for your chosen method in the BigQuery documentation.
• Explicitly Set the Reservation: During job configuration, ensure you clearly indicate the reservation ID from Project B to dedicate those slots to the process.

Key Considerations

• IAM Best Practices: Continuously review and refine permissions, removing unnecessary access to maintain a secure environment.
• Cost Management Strategies:
  • Reservation Costs: Regularly monitor slot usage across projects to ensure your reservation size is appropriate and cost-efficient.
  • Network Costs: Design your data architecture thoughtfully. Charges may apply for cross-project or cross-region data movement.
• Project and Billing Organization:
  • Labels: Tag jobs and queries using the reservation with distinct labels to simplify cost tracking.
  • Billing Sub-accounts: For complex organizations, establish separate billing sub-accounts to isolate and track slot costs granularly across projects.

[keshavhsk]

Thanks for the detailed explanation. This works for manual refresh. But how can we make use of reserved slots in case of automatic refreshing enabled?

[ms4446 · Accepted solution]

While it's possible to share BigQuery slots from Project B with Project A for various jobs and queries, directly controlling the reservation used for the automatic refreshes of materialized views managed by BigQuery is not straightforward. By default, automatic refreshes rely on the project's default reservation settings or fall back on on-demand slots if necessary.

Workarounds for Customized Refreshes

For those requiring specific control over the reservation usage for MV refreshes, the following methods offer a workaround:

1. Manual Refreshes:

• Initiate a Manual Refresh: Use the REFRESH MATERIALIZED VIEW SQL statement to manually refresh your MV.
• Configure Reservation Usage: Ensure the job executing this refresh statement utilizes the shared reservation from Project B. This can be achieved in two ways:
  • Project-Level Setting: Adjust the default reservation settings in Project A to point to the reservation from Project B.
  • Job Configuration: When using the BigQuery API, CLI, or client libraries, specify the reservation from Project B for individual refresh jobs.

2. Scheduled Queries:

• Implement a Scheduled Query: In Project A, set up a scheduled query that runs the REFRESH MATERIALIZED VIEW statement according to your preferred schedule.
• Reservation Configuration: Apply the same reservation configuration steps as mentioned for manual refreshes to ensure the scheduled query jobs use the reservation from Project B.

Important Notes

• IAM Permissions: It's crucial to ensure that the service account or user responsible for initiating the refresh jobs in Project A has the bigquery.resourceUser role on the reservation in Project B. This grants them the necessary permissions to use the reserved slots.
• Monitoring and Optimization: Keep a close eye on slot usage across both projects. Monitoring enables you to make informed decisions regarding reservation sizes and allocation, ensuring efficient use of resources and cost optimization.