HAProxy community

About reloading and old connections (before 1.8 and after 1.8)

Hi,

Before HAProxy 1.8, I understood the reloading sequence as follows:

  • A new HAP instance is launched with new config
  • The old HAP instance still runs until long-standing, old connections are closed (+/- when the traffic ends).

OK, it works, but old connections could still be there for a long time. So, during that time, 2 HAP instances are running.

HAProxy 1.8 introduces a new reloading mechanism described in : Truly Seamless Reloads with HAProxy – No More Hacks!

With HAProxy 1.8, I understand the following (after having read the article):

  • A new HAP instance is launched with new config
  • This new instance gets all sockets and then, all connections from the old instance, while accepting new connections too
  • The old HAP instance is able, then, to die quickly (as it has NO need to keep alive for holding old connections).

Is my understanding correct for HAProxy 1.8+ reloading mechanism ?

Thanks.

Dominique

No, this is incorrect.

There is no connection migration from the old to the new instance. Connection handled by the old instance will remain on the old instance, until they are closed.

1 Like

OK, thanks @lukastribus !