How to enable HTTP Pipelining with Spray-Can

I read on the spray-can docs that it supports HTTP Pipelining. But there is no method or example specified anywhere on how to do it.

Solution

This is a config setting. See this or this doc for all available settings in Spay config.

This setting turns it on:

spray.can.host-connector.pipelining = off

And this one has to be > 1 to effectively enable it:

spray.can.server.pipelining-limit = 1

By default pipelining is off.

Relevant description of each setting:

# The maximum number of requests that are accepted (and dispatched to
# the application) on one single connection before the first request
# has to be completed.
# Incoming requests that would cause the pipelining limit to be exceeded
# are not read from the connections socket so as to build up "back-pressure"
# to the client via TCP flow control.
# A setting of 1 disables HTTP pipelining, since only one request per
# connection can be "open" (i.e. being processed by the application) at any
# time. Set to higher values to enable HTTP pipelining.
# Set to 'disabled' for completely disabling pipelining limits
# (not recommended on public-facing servers due to risk of DoS attacks).
# This value must be > 0 and <= 128.
pipelining-limit = 1

# If this setting is enabled, the `HttpHostConnector` pipelines requests
# across connections, otherwise only one single request can be "open"
# on a particular HTTP connection.
pipelining = off