I know the world is falling apart with the credit crunch and all that, but please don’t call the load balancer vendor when your internet bank falls over. We’ve had a couple of messages similar to the following:
Recently I was asked by a customer for an R16 evaluation unit. After dispatching the unit it appeared the R16 would be in good company, namely; Citrix, F5, Jetnexus and CIA. The customer was evaluating a unit from all the above manufactures. Win or lose I felt this would be an interesting independent test of the R16 against some well know names………
| Loadbalancer.org are one of a number of vendors that pride themselves on offering affordable load balancing appliances that work. It is the likes of such companies that have collectively driven down the price of these solutions, making load balancing appliances available to companies who previously would not have been in a position to consider such investments.Kemp Technologies are a similar company who’s primary marketing drive centre’s around ‘value for money’. It is because of this glaring similarity that I decided to compare SSL performance capabilities, focusing on the entry-level appliance on offer from each vendor. Specification comparisons were taken, and subsequent performance tests examined whether performance levels met that of the stated specification. Results proved extremely interesting! |
A few months ago on my personal blog I wrote about the difficulty of installing CentOS on the Dell R200, owing to the SATA DVD drive used in the unit. The R200 is our unit of choice for our ClusterScale “Pegasys” product, so installing Linux distros on this server is a regular occurrence for us. Fortunately, we got hold of a Redhat driver image from Dell and we managed to load it on using a USB key. This is a simple case of typing linux dd at the installation command prompt, but note that you must copy the .img file onto the USB disk, rather than the files within the image itself.
Originally the problem was with CentOS 5.0, but as far as I know it’s still a problem with versions 5.1 and 5.2. Ubuntu installations do not seem to pose the same problem, so presumably they bundle SATA DVD drivers with the distro. I still can’t find this particular driver on the Dell site, so seems like a good idea to host it here too.
I’ve been toying with various flavors of laptops to use on my travels for a while (I’m not really a road warrior but my wife just can’t stop booking holidays).
Most of the time I get by with my trusty Blackberry for emails but sometimes you need a real computer… So I’ve always had to take a clunky laptop, normally dual boot Windows XP / Ubuntu (only need the XP as my current 3G card is somewhat flaky on Linux.).
Standard Kernel builds of LVS (Linux Vitual Server) don’t have the ability to load balance traffic that is from the local node.
For example if you terminated some SSL traffic using stunnel or pound on the load balancer you then wouldn’t be able to forward that traffic to a backend real server through LVS.
First many thanks to Siim Põder for helping to port Carlos Lozano’s patch from 2.4 -> 2.6
In order to run an SSL reverse proxy on the same node that is running LVS
i.e.
External client —> pound:443 –> Local:443 —> IPVS:80 —> RealServer
The patch for Linux Kernel 2.6.25 is here:
http://www.loadbalancer.org/download/patches/ip_vs_locallvs.patch
The following is a guide how to install on Centos 5.1:
Read the rest of this entry »
I’m going on holiday next week to a villa in Spain with the extended family. I’ll take my Blackberry & laptop with Ubuntu and a 3G card because I’m one of those sad people who like to stay in touch with the office… But I’d also like to use the laptop for my 6 year old son to watch DVDs on the plane, now thats all very well but the DVD drains the battery pretty quick and the reliability is pretty awful. So I thought no problem I’ll just rip the DVDs into ogg movie files.
Now I haven’t used any DVDs in Hardy 64 bit (only 32bit which worked fine) but I instantly hit a problem, after being automatically prompted to install the illegal gstreamer library (nice feature that auto prompt) Totem refused to play ball with the DVD:
“An error occurred Could not read from resource”
One of the (many) traditional problems with load balancing is the requirement to change your infrastructure in order to implement a hardware load balancer. Traditional DNS based round robin was easy as you just added extra IP addresses to your A record, but when using a hardware load balancer you need to get it between your clients and your servers. Some of the original units such as the CISCO 416 local re-director could be used in ‘bridge mode’ where traffic was physically forced to pass through the load balancer hardware and the packets were changed on the fly. Although this was fairly transparent it introduced a single point of failure in the load balancer unit. Most recent load balancer hardware is configured in NAT mode (like a firewall) where traffic is translated from an external subnet to an internal one while carrying out the load balancing of packets.
Open Source applications are even better in many ways, but that is another story ….
We started using an online web site chat service a while back, as it’s an invaluable sales and support tool for us. When we did a quick reckon of the market we quickly came across a problem. It was that old chestnut platform compatibility, we use a mixture of Macs, Linux (mainly Ubuntu) & a few sales guys on Windows.
“Where can I find good quality Load Balancer information?”
Well that depends if you want it to be biased or not. A lot of our comperitors have started setting up dodgy comparison sites highlighting their best features and ignoring the draw backs.
I’m not saying that I’m un-biased when it comes to load balancers I have a pretty strong opinion. But, as far as I’m aware the chart bellow is an accurate comparison of load balancing hardware, price, performance and capability:
