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Problem with GetMetadataAsync
Hi, I'm trying to test for the existence of a folder so as not to repeat myself. My understanding is that you use GetMetadataAsync and treat the folder as not there if you get an exception. (1) I'm ...
My apologies. I disovered I'd forgotten to await the delay, so it wasn't actually waiting for it. Oops! Now that I've rectified that, the code is working correctly... sometimes. I originally had a 500ms wait between each item (since Bing image search limited to 3 per second), and I still get issues at that speed (500ms later, a Dropbox folder which has been created is still being reported as not existing yet), but I decided to try having a 350ms delay between each image, and the code is working correctly at that slower speed (though otherwise that is un-necessarily slow, since I should only need to wait for each item, not each image). Also got rid of most, but not all, of the retry exceptions at the slower speed. You said there was a generous API call limit - what is it? (I've not seen it mentioned) I can try pacing my code to that and see how it goes. So, there's still an issue, but I have a work-around for the time being.
Greg-DB
Dropbox Community Moderator
Dropbox Community ModeratorThanks for following up. You shouldn't be getting 'not_found' for a path that already exists, but if you are calling to get the metadata immediately after the item is created (e.g., in the case of a duplicate in your input list), there is a chance that can happen. The CreateFolderV2Async method (as well as others, such as the upload methods) return the metadata for the new item, so I recommend keeping track of those results and de-duplicating locally, as that would likely be faster and less error-prone in this scenario.
Alternatively, you can just allow CreateFolderV2Async (assuming that's what you're using) to run whenever you are getting 'not_found', and catch the CreateFolderError on that. I.e., to ignore it if it contains a WriteConflictError.Folder.
Anyway, a RetryException isn't actually explicit rate limiting. (That would be RateLimitException.) That just indicates an issue on the Dropbox servers so you can have your app retry the request if you wish.
"Alternatively, you can just allow CreateFolderV2Async (assuming that's what you're using) to run whenever you are getting 'not_found', and catch the CreateFolderError on that. I.e., to ignore it if it contains a WriteConflictError.Folder"
I think that's the best solution. Thanks for the suggestion!
In the meantime, working on implementing that, I'm now hitting the ratelimit exceptions, so can you please let me know what the allowed rate is so that I can pace my code appropriately? Thanks.
- Greg-DB
We don't document any specific numbers for the rate limit. Apps should be written to dynamically catch and handle any rate limiting errors instead of hard coding limits. You should use the returned RateLimitError.RetryAfter value to see how long to wait before retrying.
Also, note that not all RateLimitException indicate explicit rate limiting exactly. You should check the RateLimitReason in RateLimitError.Reason to see why the request couldn't be serviced at that time. RateLimitReason.TooManyRequests indicates explicit rate limiting, but RateLimitReason.TooManyWriteOperations just indicates "lock contention". You can read more about lock contention in the Data Ingress guide.
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