Vision 'detect' not returning values from remote url since 0.90.0

Follow this closed issue #2087 , I tried different versions of vision to see when it starts happening.

I was running vision 0.70.0 and install vision like this:

npm install google-cloud --save
var gcloud = require('google-cloud');
var vision = gcloud.vision();

And it detects remote URL’s like a charm.

Since hearing this way of installing google-cloud is deprecated, I tried installing the bundle @google-cloud/vision. That’s when I encountered the same error as the closed issue. Looking closely, the new install updated my version of vision. I tried 0.70.0 and 0.80.0 which works fine.

From 0.90.0 remote URL detects gives this error:

PartialFailureError: A failure occurred during this request.
    at /Users/jasonluu/Documents/v2/node_modules/@google-cloud/vision/src/index.js:420:15
    at /Users/jasonluu/Documents/v2/node_modules/@google-cloud/vision/src/index.js:121:5
    at _combinedTickCallback (internal/process/next_tick.js:74:11)
    at process._tickDomainCallback (internal/process/next_tick.js:122:9)

errors: 
   [ { code: 500,
       message: 'image-annotator::error(12): We can not access the URL currently. Please download the image and pass it in.',
       type: 'labels' } ] }

[stephenplusplus]

@JustinBeckwith @kinwa91 @sduskis – do you think someone from the Vision team should take a look? Multiple users are reporting intermittent success with the same URL. Would you prefer they each got in touch individually with the Vision support team via the methods on their Support page?

[beccasaurus]

When fetching images from HTTP/HTTPS URLs, Google cannot guarantee that the request will be completed. Your request may fail if the specified host denies the request (e.g. due to request throttling or DOS prevention), or if Google throttles requests to the site for abuse prevention. You should not depend on externally-hosted images for production applications.

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If you want to use image.source.imageUri in your application, you need to account for the Cloud Vision API occasionally (or frequently, depending on your QPS and the hosts) returning with the error:

We can not access the URL currently. Please download the image and pass it in.

“Why? That sounds broken! I don’t understand!?”

After reading lots of use-cases and user issues, I discovered that it comes down to two limitations:

1. Being throttled by the website which Cloud Vision is making HTTP requests to for getting the image, which is controlled by the remote host, and avoiding DOS’ing their website
2. General throttling of the Cloud Vision API endpoint per Quotas and Limits

After some digging around, I found various references to the documentation of the imageUri parameter, from the actual comment on the imageUri:

• REST reference of ImageSource.imageUri
• RPC reference of ImageSource.image_uri

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To help users in the future who are learning to use the Cloud Vision API, I added this information to the main page which describes how to Make a Request, specifically in the section describing how to provide the image as either a base64-encoded string (image.content) or a URI to an image in Google Cloud Storage or HTTP(S) URL (image.source.imageUri):

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Updated website page:

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I hope this helps to explain the reason for these errors!

There are various workarounds which may or may not work for you, depending on your application:

(in no particular order):

1. Using truncated exponential backoff, which is a standard error handling strategy
   (example implementations)

2. Provide the image as a base64-encoded string to image.content (base64-encoding instructions for various platforms)

3. Provide the image from Google Cloud Storage
   (Migrating from Amazon S3 to Cloud Storage may be useful if you choose this route)

Hope this helps!