How to increase max connection on play with akka stream

How to increase concurrency http connections on play(with akka http server)?
We set the akka.http.server.max-connections = 4096(default is 1024), but server can’t accept concurrently connection more than approx 150.
And just increase backlog count.

I wanna to reduce backlog count by increase concurrency connections.

What should I do?

Is this PROD or DEV mode? If it is dev mode, then you also need to configure akka.http.server.max-connections in devSettings:

Also, which version of Play are you using?


Thank you for answer @marcospereira

I run on PROD mode and Play’s version is 2.6.12.

Additionally, I config reference.conf like this

akka {
  http {
    server {
      backlog = 1000
      max-connections = 4096

    client {
      connecting-timeout = 200ms
      idle-timeout = 500ms

    host-connection-pool {
      max-connections = 16
      max-retries = 0

Hey @wishgone,

And is this working for you?