Re: [Qemu-devel] PATCH: enabling TCP keepalives - v3

[David Ahern <dsahern@gmail.com>]

Jamie Lokier wrote:
>> The parameters I put in cause a drop after 2 minutes of no response --
>> 60 seconds of idle (no data through the socket) followed by 60 seconds
>> of failed probes. The default parameters for linux are harsh: 7 hours of
>> idle time before the first keepalive is sent.
> 
> Is 7 hours a problem worth overriding the kernel defaults for?  How
> many old VNC sessions are likely to get accumulated in that time?

The linux default is 7200 seconds; I'm not sure how I manage to convert
7200 seconds to 7 hours.

> 
> 2 minutes is a bit fast for a truly idle session, but as I said in
> another response, if you have data sent by either end, then the
> session will be broken by the lack of response in about 2 minutes
> anyway - without keepalives.


Version 5 of the patch drops the changes to the timers and the missed
probes count; it only enables tcp keepalives and the probes are sent
based on OS defaults.

david

> 
> -- Jamie