Callout Quota System

Authorized Buyers Real Time Bidding system enforces a limit on the maximal 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:

  • Protects bidders from receiving more requests than their servers can handle.
  • Conserves Authorized Buyers resources when it knows that the bidder is not interested in receiving all eligible callouts (for example, the bidder is in test mode).

Quota limit

The limit is configured and enforced per bidder server URL (technically per trading location-URL pair, but bidders should not use the same server URL in multiple trading locations). The limit can be configured by the TAM or by the bidder through the Authorized Buyers API.

When you change the limit via the API, the total quota (for all the account's URLs) is disallowed to 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; in the case that pretargeting matches exceed the requested quota limits, excess bid requests will be throttled, and the system will prioritize sending bid requests that you are more likely to bid on. However, it is still possible for the requested quota limit to be exceeded, especially in cases where the requested quota is small (approximately 1,000 QPS or less), as the Callout Quota System becomes inaccurate at small volumes. In such cases, the requested quota may be doubled (with outliers in which quota may be more than doubled). If you operate with low quota limits you should consider reducing your quota limit lower to account for the inaccuracies described above.

Error throttling

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

  • Is triggered when Google deems the error rate too high for the bidder endpoints. It will gradually lower the outgoing QPS until either the error rate or the number of bid requests drops to an acceptable level.

  • Is applied in addition to and independently of the quota enforcement. Increasing the configured quota will have no effect on error throttling, which only cares about the error rate.

  • Adjusts within minutes to changing error rates.