[zeromq-dev] Reundance/Failover Capabilites?

[Evan Klitzke]

On Mon, Oct 13, 2008 at 10:47:40AM +0200, Martin Sustrik wrote:
> I assume you are speaking about applications reconnecting after  
> network/application failure rather than about guaranteed delivery.
>
> Currently, when peer disconnects, you are notified about the event via  
> callback function and you can reestablish the connection if needed.

The question that I intended to ask is what happens when the machine hosting
`zmq_server' server process goes down. It wasn't clear to me whether or not you
were answering this question, or whether you were asking the question about
nodes connected via this zmq_server process becoming unavailable.

The specific application that I'm thinking of is this. Many clients on a
cluster need to log messages. These log messages need to be aggregated onto a
single machine, in more-or-less real time. The conventional solution for this
is a syslog service (syslog-ng, rsyslog, etc.) but they don't work well for
this application (for example, among many issues, they don't deal well with
binary log formats).

If the clients are all connected via a single instance of zmq_server than the
machine hosting the zmq_server process is a single point of failure, which is
unacceptable in this scenario. What I'm wondering is, is there a way to get
around this? Clearly I could log to multiple hosts using zmq_server and then
have some sort of log reconciliation service running after the fact, but I'm
interested to find out if this capability is built into 0MQ (or whether or not
it is planned).

Thanks for your answer!

-- 
Evan Klitzke <evan at eklitzke.org> :wq