Quotas and limits

Cloud Healthcare API enforces limits on resource usage for a variety of reasons. For example, quotas protect the community of Google Cloud users by preventing unforeseen spikes in usage. Google Cloud also offers free trial quotas that provide limited access for users that are exploring Google Cloud, including Cloud Healthcare API.

Quotas for Cloud Healthcare API are enforced by project on either a per-region or multi-region basis. Quota exhaustion in a single region doesn't affect your usage of Cloud Healthcare API in other regions.

Checking your quotas and usage

Quotas are limits on storage (also called ingress limits) and operations.

To check the available quota for resources in your project, go to the Quotas page in Google Cloud console.

To display only Cloud Healthcare API quotas, in the Filter table drop-down list, select Service and then select Cloud Healthcare API.

Not all projects have the same quotas. As your use of Cloud Healthcare API expands over time, your quotas can increase accordingly. If you expect a notable upcoming increase in usage, you can proactively request quota adjustments from the Quotas page in Google Cloud console. There is no charge for requesting an increase in quota. Your costs increase only if you use more resources.

Resource limits

Cloud Healthcare API limits the size of the content of a request, such as the size of an X-ray image in a DICOM request. You cannot request a change to a resource limit; however, in some situations you can use an import operation to import content that is larger than a resource limit.

The following resource limits apply and are subject to change.

If you attempt to process content larger than the associated resource limit, an error occurs.

FHIR executeBundle size limits

You can use the fhir.executeBundle method to perform multiple FHIR operations in a single API request. The number of operations depends on the number of entries in a batch or transaction bundle. This approach is more efficient than making individual API calls for each operation.

Processing times for fhir.executeBundle requests increase with the number of entries in the bundle. Factors like resource contention (for example, updating the same resource as part of many transaction bundles in parallel) can also impact performance. For examples of when resource contention can occur and how to prevent it from causing errors, see Data throughput best practices. Large bundles, especially those exceeding 1,000 entries, might time out and fail to complete.

To ensure successful and timely processing, consider these limits when sending your fhir.executeBundle requests:

• Transaction bundles: Bundles exceeding 4,500 entries are immediately rejected to prevent timeouts. Transaction bundles require all operations to succeed.
• Batch bundles: No specific entry limit exists, but larger bundles increase the risk of timeouts. Timeouts might result in partial success, with only some entries processed.

Using import operations for content that exceeds resource limits

Import operations permit you to process content that is larger than the associated resource limit. The content size in an import operation is limited only by the Google Cloud maximum storage size of 5 TB for individual objects. Import operations are subject to storage quotas that determine how long an import operation takes. You might want to use an import operation, for example, if you want to store many DICOM instances in a DICOM store and don't want to be subject to the request size limit. Rather than uploading the instances using the available Store Transaction methods, you could instead upload the instances into a Cloud Storage bucket and then import them into the DICOM store.

For detailed steps to import DICOM data using an import operation, see Importing and exporting DICOM data.

For detailed steps to import FHIR resources using an import operation, see Importing and exporting FHIR Resources.

For detailed steps to import HL7v2 messages using an import operation, see Import HL7v2 messages from Cloud Storage.

Request a change to quota

To request a change to a quota, you must have serviceusage.quotas.update permission. This permission is included by default for the following predefined roles: Owner, Editor, and Quota Administrator.

1. Go to the Quotas page.

   Go to Quotas

2. In the Quotas page, select the quotas that you want to change. If you want to display only Cloud Healthcare API quotas, select Service from the Filter table drop-down list and then select Cloud Healthcare API.

3. Check the boxes of the quotas that you want to edit.

4. Click the Edit Quotas button at the top of the page.

5. Fill out the form and then click Next.

6. Enter the limits that you are requesting and then click Next.

7. Click Submit request.

A request to decrease quota is rejected by default. If you want to reduce your quota, reply to the support email with an explanation of your requirements. A support representative will respond to your request.

You will receive a response from the Cloud Healthcare API team within 24 to 48 hours of your request.

Plan to request additional resources at least a few days in advance to make sure that there is enough time to fulfill your request.

Location quota requests

You can request a quota increase for the Cloud Healthcare API in a specific region, or in a multi-region location.

To request a quota increase in a single region: In your quota increase request, specify the region.

To request a quota increase in a multi-region location:

• For a quota increase in the us multi-region, state in your request that the quota is for "US meta region."
• For a quota increase in the eu multi-region, state in your request that the quota is for "EU meta region."

Quota limits

The following sections describe the quotas associated with Cloud Healthcare API data stores and operations.

DICOM quotas

The following table describes the Cloud Healthcare API quotas associated with DICOM stores and DICOM operations.

FHIR quotas

The following table describes the Cloud Healthcare API quotas associated with FHIR stores and FHIR operations.

Multi-operation searches

A single request can consume multiple quota units. For example, a GET search request using Observation?subject:Patient.identifier=system|value as the search parameter consumes two fhir_search_ops quota units. Two search operations are performed, one on the Observation resource and one on the Patient resource, using the subject as a reference.

If a conditional delete request using Observation?status=canceled as the search criteria searches for and deletes six Observation resources, the following quota units are consumed:

• One fhir_search_ops quota unit, because the GET search request is only performed on one type of FHIR resource, the Observation resource. The request returns all Observation resources matching the search criteria.
• Six fhir_write_ops quota units, because there are a total of six DELETE operations on the deleted Observation resources.

Execute bundle quota consumption

To send an execute bundle request, regardless of the quota the request consumes, your Google Cloud project must have at least one unit available for each of the following quotas:

• fhir_read_ops
• fhir_write_ops
• fhir_search_ops

If these quotas aren't available, the execute bundle request fails.

For example, if you send a fhir.executeBundle request with a transaction bundle containing 100 POST operations, each of which creates a FHIR resource, the Cloud Healthcare API first verifies that at least one quota unit is available for fhir_read_ops, fhir_write_ops, and fhir_search_ops. If the verification succeeds, the Cloud Healthcare API executes the bundle and creates the FHIR resources, which consume a total of 100 fhir_write_ops quota units.

Consider the following transaction bundle, which uses a conditional reference to create an Observation resource if the reference exists:

{
  "resourceType": "Bundle",
  "type": "transaction",
  "entry": [
    {
      "request": {
        "method": "POST",
        "url": "Observation"
      },
      "resource": {
        "resourceType": "Observation",
        "subject": {
          "reference": "Patient?identifier=a1b2c3d4e5"
        }
      }
    }
  ]
}

When you execute the bundle, the Cloud Healthcare API first verifies that at least one quota unit is available for fhir_read_ops, fhir_write_ops, and fhir_search_ops. If the verification succeeds, the Cloud Healthcare API executes the bundle. The following quota units are consumed:

• One fhir_write_ops to create the new Observation resource.
• One fhir_search_ops, because a single search operation is performed on the Patient?identifier=a1b2c3d4e5 reference.

Best practices

For best practices on managing Cloud Healthcare API quota, see Quota management best practices.