Provisioned Rate exceeded on DeleteFaces in Rekognition

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I am getting a Provisioned Rate exceeded error when calling the DeleteFaces api of AWS rekognition, using the current version of the .net DSK.

I think what triggered the error in the first place is that I was running some batches in parallel, and even though they don't make many calls to AWS rekognition, it happened occasionally that their calls were simultaneous, exceding the limit of 5 per seconds (I managed retry attempts but I had not realised the SDK had its own retry policy by default).

However it seems now that any single call I make to DeleteFaces returns a "Provisioned Rate exceeded" exception, no matter how long I wait before I retry (>1h), or how many face ids I try to delete per call (50 to 4096), or the retry policy of the sdk (legacy or standard). Other functions of the rekognition API seem to work fine. Is there a rate limit other than the 5 calls per seconds advertised as a default for rekognition (and when that limit is reached, how long does it take before it allows new calls)? Or is it some sort of shadow ban after a certain number of provisioned rate exceeded errors (and if so how long should I wait before the ban is lifted)? Does it matter how many faces I delete in one call? I already batch faceids by batches of 4096. Do these get further split by the .net sdk in multiple calls, resulting in some sort of api calls amplification?

Charles
asked 2 years ago1082 views
2 Answers
1
Accepted Answer

Hi Charles, the particular limit you're hitting is an internal limit that's currently not listed in the public documentation. Could you open a case using this link or file a limit increase on DeleteFaces API and we can then engage on the case to help.

We understand that the limit is not a good customer experience and there're a few options that's available to help.

AWS
answered 2 years ago
  • Thanks. I have already requested a limit increase (thinking I was somehow hitting the 5 calls/s.) I will mention your comment. If it is not confidential, I would be curious to know what that internal limit consists in, just so I can code to stay clear of it.

1

Hi!

The 2 pages I'm looking at are https://docs.aws.amazon.com/rekognition/latest/dg/limits.html and https://docs.aws.amazon.com/general/latest/gr/rekognition.html.

I don't see anything else. Could you check https://us-west-2.console.aws.amazon.com/servicequotas/home/services/rekognition/quotas/L-220834FB (Use the region you're working in) and see the history?

Some options include configuring exponential backoff and jitter, configuring retries, queuing as well. Alternatively, you could increase the service quota too.

jsonc
answered 2 years ago
  • The page shows a <5% usage of the deletefaces. I just retried, and I managed to get one batch of 4096 faces deleted, but the second batch (5s pause between) of 4096 failed with the provisioned rate limit error. I went into cloudwatch so I can see the exact metrics for the deleteface api, and I can see exactly two calls in the last hour, one successful, one throttled. I am using Ireland but I believe the limit is 5 calls/s everywhere. I am clearly not hitting that limit. I wonder if it has something to do with the size of the collection (>500k), but that is well within the 20m limit.

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