30 Days of NetScaler: Day 8 Priority Load Balancing.
Is it not just load balancing Jim?
Welcome to Day 8.
Load balancing is one of those ‘delivery essentials’ that every network admin needs to get a grip on.
Please don’t bother me! I know this load balancing stuff inside out…..Ok, no problem, but what if you need to be smarter about balancing traffic with different groups of servers?
You have requested some training; your memory might be a bit hazy as there was a football game at the weekend and the team just didn’t turn up! Who would be a football supporter? Anyway, the plan is to offer some pointers on NetScaler, with a series on all things related to the appliance. The goal is to provide you with enough information to be actually dangerous when talking to a customer or client. The number of days is a bit of an arbitrary number, but I am prepared to give you 2 minutes of material. Can I get 2 minutes of your time?
I have spoken about Load balancing, GSLB, Content Switching, Software Bundles, NetScaler instances, nFactor, and AppExpert. If you missed those earlier ones, you can catch them here
Today is all about Priority Load Balancing.
Honestly, what are you talking about?
You have a job that needs to load client connections onto a ‘Service’ - a generic term. Maybe you need a way to assign some kind of hierarchy to the various servers on the backend. You have a NetScaler spun up and ready to go. Could it handle this?
Of course, NetScaler has your back!
So what? What problem does it solve?
Let’s assume that your business has a website, the web server estate has grown over time, and there is a mix of systems, some newer and faster than the others. Your preference is to max out the newer systems before falling back to the older boxes. This fall back could be for several reasons.
How can you control the traffic and the setup to manage the connections to accommodate that? Priority Load balancing, of course!
Who would be interested in this?
Anyone who runs a network and needs specific web traffic modification capabilities from NetScaler for an access scenario. It is common for NetScaler to be added for something internet-facing, as it allows the admin to better manage traffic to the backend.
There are two license levels for NetScaler now, and both include Priority Load balancing!
What does Priority load balancing offer?
Thanks to the docs team for some great diagrams! I have taken these from here.
Here we have condition 1: Clients are being served by Priority group 1, everything is good. Groups 2 and 3 are waiting for something bad to happen to that priority group.
Here we have Condition 2: For whatever reason, Group 1 was taken offline. We still have Group 3 as a contingency to back up Group 2.
Seems cool, what if I need more than three Priority Groups? The maximum number of Priority Groups is ten, which should cover most deployments.
Any limitations?
Configuration is via the GUI only, which surprised me.
I need a graphic to show it in action!
I have taken this from the NetScaler GUI, a neat graphic(11 seconds) if the diagrams above were not sufficient.
Summary.
NetScaler comes in many different formats and has a common code base across all appliance types. Many devices can load balance things, however, NetScaler has maturity with killer features like Priority Load balancing that give you options you didn’t realise you needed. This helps you keep serving your load irrespective of what is going on in the DC.
These all aid in giving a better user experience for your users.
Whatever feature it is, NetScaler has your back.
NetScaler is all about no-limits networking, I think that about sums it up.