Faster TCP keepalive

Faster TCP keepalive

[Stephen Suryaputra Lin]

Greetings,

I'm writing this to probe if there has been thoughts or efforts in
allowing sub-second TCP keep alive interval? One application is for TCP
connections between IP hosts connected by an internal backplane where a
faster detection is a necessity and the increased traffic can be
accommodated.

Suggestions on other ways to quickly tearing down TCP connections to a
rebooted host in the application above are welcomed.

Thank you,

Stephen.

RE: Faster TCP keepalive

[David Laight]

> From: Stephen Suryaputra Lin
> Sent: 23 June 2017 20:58
...
> Suggestions on other ways to quickly tearing down TCP connections to a
> rebooted host in the application above are welcomed.

Arrange to send an RST for each connection during shutdown.

	David

Re: Faster TCP keepalive

[Lance Richardson]

> From: "Stephen Suryaputra Lin" <stephen.suryaputra.lin@gmail.com>
> To: netdev@vger.kernel.org
> Sent: Friday, 23 June, 2017 3:58:17 PM
> Subject: Faster TCP keepalive
> 
> Greetings,
> 
> I'm writing this to probe if there has been thoughts or efforts in
> allowing sub-second TCP keep alive interval? One application is for TCP
> connections between IP hosts connected by an internal backplane where a
> faster detection is a necessity and the increased traffic can be
> accommodated.
> 
> Suggestions on other ways to quickly tearing down TCP connections to a
> rebooted host in the application above are welcomed.
> 

For quickly tearing down TCP connections to a host that has been rebooted,
avoiding e.g. waiting for TCP max retransmit count to be reached), you
could use SOCK_DESTROY (as e.g. iproute2's "ss -K [ FILTER ]" does).

Regards,

  Lance

> Thank you,
> 
> Stephen.
>