Linux equivalent of Windows NLB

Question

With Windows, we can setup load balancing for arbitrary IP services just by installing NLB and selecting which nodes we want in the cluster. It does some MAC address changing, then has algorithms to decide which node handles an incoming request.

Is there a production grade equivalent for Linux? I don't want something that requires a front server to sit physically (network-wise) in front of the machines (like certain hardware LBs do, and Linux Virtual Server does, AFAIK). I want something that'll act similar to Microsoft's NLB -- pick N nodes, they all listen on the same IP, and divvy up the incoming requests.

Solution 1

Here are a few that people find quite good in the Linux community (minus LVS at your request). I personally have only used HAProxy so your mileage may vary.

HAProxy
Balance

Only supports load balancing for http/https requests:

Pound
PLB - Pure Load Balancer

Solution 2

see: http://lnlb.sourceforge.net/

Seems to be exactly what you are asking for.

That page summarizes it as: a common IP shared between all nodes (on a virtual interface). All you have to do is to bind on the virtual interface, the driver will do the rest.

It sounds very much like Windows NLB.

Solution 3

If you want a loadbalancing like NLB you should have a look at clusterip in iptables. -> http://security.maruhn.com/iptables-tutorial/x8906.html

It does exactly the same, only the failover part is missing, but maybe there exists some tools for this.

Solution 4

• If you are interested in BSD solutions - see CARP, linux as i just found out has port of it called UCARP
• About DNS-level load-balancing see CDN rfc3568, but beware - DNS-lb is kinda inert
• LVS is still pretty good so - check it out

Solution 5

Round robin DNS would be the simplest solution, but maybe it's too simple for your requirements.

View more solutions

Comments

[Shaun Hess]

What kind of traffic are you trying to load balance (HTTP/S)?

[womble]

"just"... hahahaha

[Gareth Williams]

OK, yea, NLB can be a pain to setup sometimes. But assuming you got the NICs setup properly beforehand... it's pretty point and click.

[Pieter]

I dont like NLB, it is a hack, flooding multicast traffic to all ports in the NLB server subnet, thus out all the ports.

[Gareth Williams]

Yea DNS would not work. That assumes you have intelligent enough clients that actually use DNS. A lot of services simply go right to the IP.

[Gareth Williams]

Oh I didn't realise you could have virtual and real sitting on the same box.

[Gareth Williams]

Thanks. By looking at them, they seem to put a separate box in the picture, no? Like, you have the frontend server which rewrites the Layer2 packet, then the server response either must physically pass through the frontend box, or use Direct Server Return (like a Foundry, for example). Whereas NLB simply runs on each host itself. But I'll dig more - perhaps I'm misunderstanding something.

[Decebal]

add Ultramonkey to that list, it uses LVS but doesn't need a separate witness server.

[Decebal]

you could set round-robin sessions on the switch instead.

[Gareth Williams]

I found his answer helpful, it IS exactly what I was looking for. I don't see how the question being 5 years old changes anything. Anyone coming across this question now can see there's a solution that, according to their webpage, sounds pretty impressive.

[Aaron Hudon]

Unfortunatelly lnlb has not seen update in a long time and depends on Kernel support.

[Aaron Hudon]

Yes but you cannot have it sit on both real servers (at least not in anactive/active way like NLB does).