Rebuild resource grouping and authorization when moving metric queries to getBatch

Source facts

Azure Monitor’s metrics:getBatch query accepts at most fifty distinct resource IDs, all sharing a subscription, region and resource type. It uses a subscription-level POST to a regional metrics endpoint; resource IDs move into the request body. The body property resourceids must be lowercase. Microsoft Learn.

Unlike individual metric queries, this API requires Monitoring Reader on the queried subscription. Having that role on every requested resource is insufficient. Custom metrics and namespaces that are not resource types are unsupported. Each returned resource’s metric list includes its resourceid for identification. Microsoft Learn.

Applicability

Use this migration check for Azure Monitor clients moving standard metric queries to metrics:getBatch. Do not include guest metrics merely because the same client can retrieve them through another API.

DSE recommendation

DSE recommends building the grouping plan from actual resource inventory before changing the request loop. Review whether subscription-level monitoring access is appropriate for the caller; do not silently expand privileges to make a migration pass. Preserve separate query paths for unsupported namespaces. Update response handling to associate results with explicit resource IDs instead of assuming a single-resource response.

Verification

Compare a small approved batch with individual queries over the same time window, metrics and dimensions. Confirm every requested resource is accounted for and verify the caller’s real permission scope. Exercise an intentionally incompatible grouping in a test path to confirm the client reports the failure clearly rather than presenting an empty dashboard as success.

Official references

Microsoft Learn: Migrate to the metrics getBatch API.