An app I'm working on is making requests to the SGAPI for a large amount of URLs. (it's following friend links, much like the "find missing links" demo does.)

In some cases I seem to be getting back either "invalid request" or "service unavailable" error responses. I've been unable to figure out exactly what triggers them, but generally for any particular request URL the same URL will be returned consistently as far as I can see.

My app batches up requests following the example of the missing links demo. I was initially capping each request to 15 URLs as that demo does, but when I found that I was still hitting errors I also put in an upper limit for how long the value of the "q" argument can get, which is currently set to 600 since this seems to be a sweet spot that allows my fetches to complete most of the time.

Is there any upper limit on either the number of URLs or the length of the query string for a particular request?