undici pipelining & idempotent

If you want to take advantage of HTTP pipelining with undici you should probably set the idempotent: true option to the POST/PUT requests that are idempotent, e.g. /_bulk. Otherwise undici won’t pipeline them.

Refs: https://undici.nodejs.org/#/docs/api/Dispatcher?id=parameter-dispatchoptions

[delvedor]

It is very important that the client fully consumes any and all response bodies. Might be worth to add to documentation if end-users are able to have streaming responses.

By default, the client will always consume the body (you can find here how undici is being used), but advanced users can pass the asStream option which will give them back the raw stream from undici. You are right that we should mention the risks of doing so in the docs 😃

[ronag]

Elasticsearch has no timeout or pipelining limit and sends no hints 😃

Then you might want to set keepAliveTimeout: 5 * 60e3 or something so that undici doesn’t aggressively disconnect. The default is quite short to be safe.