Improved defaults for sink rate limits

This release removes some conservative defaults for HTTP-based sink request rate limiting and concurrency.

Previously, many sinks were defaulting to a limit of 5 requests / second (for example the http sink) with a maximum number of concurrent requests of 5, but these limits were rather arbitrary and artificially constrained throughput. With this release, we’ve updated the default for most HTTP-based components to have no rate limiting and a maximum number of concurrent requests of 1024.

To configure a request rate limit or maximum concurrency on a HTTP-based sink, you can set the request parameters like:

request.concurrency = 5 # limit to 5 in-flight requests
request.rate_limit_num = 10 # limit to 10 requests / second

If you haven’t already, we recommend trying out our adaptive concurrency controller to have Vector automatically determine the optimal number of in-flight requests to maximize throughput. You can do this by setting request.concurrency = "adaptive". We are planning for this to be the default behavior in v0.17.0.