[rsyslog] Multiple-server failover questions (and round-robin DNS resolution, too)

[Ryan Lynch]

Hi, David,

On Wed, Dec 9, 2009 at 12:30,  <david at lang.hm> wrote:
> this sort of thing is possible today, without using round-robin DNS
>
> on linux there is an iptables option called CLUSTERIP that lets you create
> a single IP address on multiple machines, and each machine processes a
> portion of the traffic (based on a hash of one or more of dest port, dest
> IP, source port, source IP)

ClusterIP is a heck of a neat technology, and it would definitely work
for a lot of load-balancing cases.

But it does require that all of the participating hosts share a single
LAN segment. In my case, the "central" log-receiving hosts are are
different physical sites, and are separated by routers.

I haven't thought this out, completely, but depending on the load
characteristics and proximity-distribution requirements, it might be
possible to use a combination of both: A per-site ClusterIP address
for the primary host, with various clever round-robin DNS records for
failover.

Either way, thanks for the suggestion.


> if you have many systems sending to one central server they will be spread
> roughly evenly across the servers. if this is not even enough for you,
> version 5 has an option to close and re-open connections to the server
> every X messages, and since doing so changes the source port of the
> connection, this will spread the connections around the cluster more
> evenly.

Do you happen to know what the name of that option is? That will come
in handy no matter how I end up implementing this.

-Ryan