[zeromq-dev] Disconnect notification.

[Martin Sustrik]

Pieter,

>> The heartbeats are an interesting problem. I haven't yet made my mind
>> about them. AFAICT the only real use cases for heartbeats is in
>> high-availability systems to initiate fail-over.
> 
> There is probably a wider use case, based on detecting network
> problems before TCP times out, and on detecting blocked (looping)
> peers.  Admittedly blocked peers is unlikely with 0MQ handling IO but
> it's not excluded.
> 
> You probably only need _aggressive_ heartbeating (under a second) on
> HA systems.
> 
> I'm trying to recall the websocket discussion on heartbeating (and
> that is not for HA systems but for wider Internet use) but that list
> is rather confusing.

What I meant was: What else can the heartbeats be good for aside of the 
failover? Even if you use them in your GUI app to check the server 
availability, then display "server unavailable" dialog box, the user 
would just call the service provider and ask them to restart the server 
(or something similar) which is actually a failover carried on by 
different means.

Martin