Callout Quota System

The Authorized Buyers Real-time Bidding system has a maximum rate of callouts, expressed in Queries Per Second (QPS), that can be sent to a bidder's servers. Pretargeting matches that exceed the limit are dropped. The limit serves the following purposes:

  • Protect bidders from receiving more requests than their servers can handle.
  • Conserve Authorized Buyers resources when the bidder isn't interested in receiving all eligible callouts, for example, if the bidder is in test mode.

Quota limit

The limit is configured and enforced per bidder server URL, technically per trading location-URL pair. However, bidders shouldn't use the same server URL in multiple trading locations. The limit can be configured by a Technical Account Manager (TAM) or by the bidder through the Authorized Buyers API.

When you change the limit through the API, the total quota for all the account's URLs can't exceed the total quota configured internally by the TAM.

The maximum quota limit for your bidder also depends on your recent spend. Your effective quota limit before error throttling is the minimum of the configured quota and spend-based quota. You can view your spend-based quota on the RTB Graphs dashboard.

The Callout Quota System attempts to not exceed the requested quota limit per bidder server URL. More than 15K QPS, the system generally adheres to within 10% of the QPS limit, and more than 45K QPS, it generally adheres to within 5% of the limit—often 1 to 2%.

Sometimes bid requests you're likely to respond to are prioritized based on your recent bidding history. Here are some features Google uses to identify requests you're likely to bid on:

  • Publisher IDs
  • Environment type
  • Ad format

Programmatic Guarantee requests are always prioritized.

The Callout Quota System is less accurate at small volumes. The requested quota limit can be exceeded if the requested limit is about 1,000 QPS or less. In such cases, the requested quota can be doubled or occasionally more than doubled. If you operate with small quota limits, you should consider reducing your quota limit to account for these inaccuracies.

Callout spillover

Cross-North America callout spillover helps maximize the number of bid requests you receive within your QPS quota limit. This feature only applies to bidders with server URLs in North America.

There are two Real-time Bidding (RTB) trading locations in North America. When a callout is sent to one of these North America trading locations and RTB detects that your bid request quota limit is already met there, it transfers the callout to the other location, and tries to send a bid request to your server URL there.

For example, if RTB is processing a callout in the North America East Coast trading location and detects that your East Coast server URL's quota limit is already met, RTB then transfers the callout to the North America West Coast trading location and tries to send a bid request to your West Coast server URL instead.

If your quota is full in both locations, the callout is throttled.

Error throttling

The Callout Quota System uses error throttling. It sends less callouts than it can if the bidder doesn't respond to bid requests in time or if the bidder's responses are invalid. Note that error throttling:

  • Triggers when Google deems the error rate too high for the bidder endpoints.

  • Gradually lowers the outgoing QPS until the error rate or number of bid requests drops to an acceptable level.

  • Is unrelated to the quota limit.

  • Adjusts within minutes to changing error rates.