I'm building a pretty large app for a client, and had some questions about heavy API usage.
Basically this app is going to aggregate feeds from various sources. My client estimates around 900 follow-able users will be in this system to start out, with more being added over time. He wants to update the feed data every 15 minutes, so we would need to update one user feed per second, assuming 900 feeds and a 15 minute TTL. As the requests take a few seconds to complete, we would then need to load balance across a few threads to tackle the queue asynchronously.
My question is, should I be worried about quota errors or hitting any kind of limitations? If so, what are our options?
I've already read their help pages and documentation, and it's very vague and not really helpful. I need concrete numbers. It's not feasible to load test their API to figure out the limitation. The matter is not helped by Google deferring all support to a non-official channel such as StackOverflow where people do not have knowledge of the Youtube internals.
Thanks in advance...
Answer
Version 3 of the YouTube Data API has concrete quota numbers listed in the Google API Console where you register for your API Key. You can use 10,000 units per day. Projects that had enabled the YouTube Data API before April 20, 2016, have a default quota of 50M/day.
You can read about what a unit is here: https://developers.google.com/youtube/v3/getting-started#quota
- A simple read operation that only retrieves the ID of each returned resource has a cost of approximately 1 unit.
- A write operation has a cost of approximately 50 units.
- A video upload has a cost of approximately 1600 units.
If you hit the limits, Google will stop returning results until your quota is reset. You can apply for more than 1M requests per day, but you will have to pay for those extra requests.
Also, you can read about why Google has deferred support to StackOverflow on their YouTube blog here: https://youtube-eng.googleblog.com/2012/09/the-youtube-api-on-stack-overflow_14.html
There are a number of active members on the YouTube Developer Relations team here including Jeff Posnick, Jarek Wilkiewicz, and Ibrahim Ulukaya who all have knowledge of Youtube internals...
UPDATE: Increased the quota numbers to reflect current limits on December 10, 2013.
UPDATE: Decreased the quota numbers from 50M to 1M per day to reflect current limits on May 13, 2016.
UPDATE: Decreased the quota numbers from 1M to 10K per day as of January 11, 2019.