I am learning about Amazon Web services. I just want to know what is the maximum number of connections(roughly) that can be held by Amazon S3 simultaneously without crashing…
Theoretically this is infinite. To achieve this, they use a partitioning scheme they explain here: http://docs.aws.amazon.com/AmazonS3/latest/dev/request-rate-perf-considerations.html
Basically they partition your buckets on different servers based on the first few characters of the filename. If those are random, you scale indefinitely (they just take more characters to partition on). If you prepend all files with
file_ or something (so S3 cannot partition the files correctly because all files have the same starting characters), the limit is about 300 GET / sec or 100 PUT/DELETE/POST per second.
See that page for an in-depth explanation.