[zeromq-dev] Heartbeating using TCP keepalives

[Pieter Hintjens]

On Fri, Jan 3, 2014 at 11:54 AM, KIU Shueng Chuan <nixchuan at gmail.com> wrote:
> What should be the behavior if the user specifies 1500ms but the underlying
> OS only supports seconds granularity?

Presumably to round up. What if the user specifies 1ms? Rounding down
would not work.

A heartbeating option should probably be abstracted from system
capabilities. Even if we implement this today using TCP's timeouts,
tomorrow we may want to use ZMTP heartbeating. In that case, fractions
of seconds would be fine, and useful for e.g. clusters where failover
has to happen within a second.

Anyhow, we don't really know. The way to decide is to implement this
patch, try it, and refine it through use.

-Pieter