If you’re reading this blog, you probably have a Mac server setup somewhere that requires your attention occasionally. For those of you with an iPhone, I hope to help you out.
Every once and a while, I’ll get an email asking if we can take a load balancer in our cage. Load balancing is a technique to spread work between two or more computers. So naturally, a load balancer is hardware that makes this possible. The idea is to have multiple Mac minis to host a website so it continues to perform well for high traffic. Since our network and racks are tailored specific for Mac minis, we don’t install load balancers. But, we recommend a much better and less expensive way to do load balancing. We suggest DNS, or more specifically, round robin DNS.
Round robin DNS is a way for one domain to be spread between multiple machines. This way, each time the domain name is called, the request will be forwarded to a different machine. Below is an example of what it might look like courtesy of DNSMadeEasy.com)
So in this case, half of the requests would be sent to 192.168.1.2 and the other half would go to 10.2.54.4. Now each machine only handles 50% of the load. You can easily use up to 13 different ip addresses to really spread the load.
As you can imagine, there are some nice benefits to using Round Robin DNS:
- No extra hardware to purchase. (Load Balancers can cost thousands.)
- When used with DNS Failover, you could have one Mac mini go down and not have it apparent to the end users. It just gets dropped from thr Round Robin until it comes back online.
- Rather than using just one Xserve, you can use five or six Mac minis. Place them on different power strips, attached to different switches, and behind different routers. This way, should any of hardware fail (XServe, power, switch or router), there are still machines available.
- It’s easy to setup, and to add additional machines later. When your budget allows for another machine, just put it in the circle.
We have a few customers doing this now and it’s worked great. If it’s something that might help your company, we’d love to work with you. Just let us know.