Jeremy Laidman <user-71895fb2e44c@xymon.invalid> wrote on 11/13/2011 10:32:21 PM:
From:
Jeremy Laidman <user-71895fb2e44c@xymon.invalid>
To:
Chris Ahrens <user-d6ad043dbb12@xymon.invalid>
Cc:
Date:
11/13/2011 10:32 PM
Subject:
Re: [Xymon] Listening on Mulitple IPs
On Fri, Nov 4, 2011 at 5:23 AM, Chris Ahrens <user-d6ad043dbb12@xymon.invalid>
wrote:
My Xymon server has 3 IP addresses that I want to spread out my
incoming
status messages on. I did not use the --listen so that xymond would
come up
to use 0.0.0.0:1984 and netstat shows it listening on 0.0.0.0:1984,
but when
I look at the network traffic 99.9% of it is on eth0.
Is that incoming or outgoing or both? I believe outgoing traffic will
route via the "primary" interface regardless of the interface on which
it arrived, unless you have policy routes in place. So you might have
a spread of incoming packets among interfaces, but all outbound
packets from a single interface.
It was the incoming that wasn't being split up on the different interfaces that I was looking for.
My client servers are using the dns entry of the Xymon server and dns
has
all 3 IP addresses of the Xymon server associated correctly.
Is it possible that your resolver is configured to deliver round-robin
records in fixed order? Try an "nslookup" a few times and see if the
order of the 3 IP addresses is changing. Also look at the TTL of the
records, to see if it's large, because clients might use the same
record for a period of time based on the TTL. Also, try "getent hosts
<record>" a few times to see if the order is changing, as this will
indicate what the stub resolver is giving to resolver clients (such as
the Xymon client).
DNS round-robin is very poor for load-balancing. It's not that great
for fault-tolerance either. You might try using some kind of
interface-based traffic sharing, such as bonding.
Cheers
Jeremy
The DNS was round-robining just fine to all three IP addresses. The server setup is a hot failover and therefore has virtual IP addresses. The admin that built the server had setup all the virutal IPs to eth0 which is why all incoming traffic was showing on that interface. Bonding the interfaces would probably be the best idea but I was just configuring Xymon and couldn't get the person building the server to bond the interfaces.
Thank You,
Christopher Ahrens
Macy's Systems & Technology
user-d6ad043dbb12@xymon.invalid