HTTP-based sinks now use adaptive concurrency by default

Originally released as an opt-in feature in v0.11.0, Vector’s adaptive concurrency has been promoted to the default behavior for all HTTP-based sinks. This was following months of testing and feedback from users that had opted into adaptive concurrency. We expect users to see an overall improvement in the throughput of Vector along with Vector automatically backing off in the face of increased pressure downstream, to avoid overwhelming the sink destination.

This feature was previously able to be opted into with the following configuration:

request.concurrency = "adaptive"

This is the new default for HTTP-based sinks. As mentioned in the announcement blog post the adaptive concurrency controller will automatically respond to back-pressure from the destination of the sink (in the form of increased response times or explicit HTTP 429 response codes, among others).

We welcome any feedback from users in our Discord server!

If you would like to instead use a fixed concurrency as was previously the default, you can set a static value like:

request.concurrency = 5

This will tell Vector to limit to 5 concurrent requests.