Louwrentius

I was looking at open-source load balancing software and it seems that there isn't a nice overview except from this website, although many of the listed projects seem dead.

I've made a selection of products that seem to be relevant. The biggest problem with open-source software is that projects are abandoned or unmaintained. So I created this table and added a column 'last product update' which gives you a feel for how active the project is.

I currently don't have hands-on experience with these products. Some of those products are briefly discussed at this blog - worth a visit.

There are many more products but most seem to be abandoned years ago. If you feel there are more products that are noteworthy but not in this list, feel free to contact me or comment about it.

It seems that the top-3 web servers like ngnix, Apache and Lighttpd all have support for load balancing. It depends on your needs, time and knowledge if you want to invest in other products or stick with the web server software you know.

At this location some people are talking about the pro's and con's of commercial off-the-shelve products vs. home-grown open-source solutions.

In this day and age of dynamic web content, how relevant can a caching proxy server be? I believe that the answer could be: quite!

I have installed a caching proxy server based on Squid, which is now used within my company. It also does content scanning using squidclamav and Clamav. I wrote an article about how to setup such a content scanning proxy.

The thing is that I didn't much care for the actual caching functionality of Squid, I deemed the content-scanning part more interesting. But I'm quite pleased with the actual caching hit ratio.

It seems that we have a hit ratio between 20% to 25% and that is more than I expected. Most content is dynamic in nature, so I would expect that most content is not cached but it seems that there is still quite some data that can be cached. This must also improve the end-user surfing experience as latency for downloading content should be reduced.

Of course, this is just a sample for the last hour. However, multiple measurements at different moments yield similar results.

I think this result proves that a caching proxy server is still relevant, especially if you don't have a fast internet connection. If you do, you can still improve the overall browsing experience due to the fact that data is cached.

There is a caveat: the proxy server itself also introduces latency. I haven't performed a side-by-side comparison and measured actual responsiveness of browsing with or without a proxy.

Updated October 24, 2012, see below.

This post is a description of my home network setup based on gigabit ethernet. I did a non-standard trick with VLANs that may also be of interest to other people. I'm going to start with a diagram of the network. Just take a look (click to enlarge).

I now have replaced my Mac Mini with a HP N40L router based on Ubuntu 12.04 LTS. This server is now placed in the basement. The managed netgear switch is swapped with the Airport extreme.

Design

I have a Mac mini running Linux that acts as my internet router. The closet that houses the cable modem is not a friendly environment for such a device and there is not a good location for it. The closet is also outside of my house, behind a door not too well protected. So this is why I keep my router inside my house.

From this closet, one UTP cable terminates in the living room, the other in the basement. This configuration has a very big problem. How do I run two different networks over one wire?

I have to connect my iMac to my 'internal' home network. However, the Mac mini must be connected to both the internet network segment (connected to the cable modem) and the home network. All through a single UTP cable.

Therefore I use VLANs. I transport both the internet network and the local home network though one cable. VLAN 10 is for internet, VLAN 20 for my local home network. For this all to work you need managed switches that support 802.1q.

How traffic flows

So let's say that the server is accessing the internet to obtain the latest Linux security updates. How does this network traffic flow through the infrastructure (click to enlarge)?

All internet traffic must flow through the router. Thus, even if the traffic from the basement travels through the switch next to the cable modem, it must first travel to the router in the living room. There the router decides if the traffic is permitted to go out to the internet and thus enter the internet VLAN.

Pros and cons

Pros:

• Just a single cable to the living room
• no extra USB-based ethernet adapters required for the Mac mini
• Mac mini resides in save and computer friendly environment

Cons:

• Managed switches supporting VLANs are relatively expensive