4 posts tagged with "Performance"

One of the weirdest birthday presents I got this year was from Microsoft - Azure Firewall Prescaling. It's a solution to a problem that's been around for a while. And one that quite a lot of people didn't even know existed.

Azure Firewall is a great product, but it's not without its limitations. One of the biggest issues has been around scaling. Sure, Azure Firewall can scale up and down based on demand. But this scaling can take time. In high-demand situations, this delay can lead to dropped packets and degraded performance.

The scale back in can also cause issues with long-lived TCP connections. Why? Because there's been little control over when the scaling events happen. And which instances are terminated.

In my previous post, I shared some basic latency tests across Azure networks. The results were pretty predictable: the closer things are physically, the faster they communicate. Not exactly groundbreaking.

But when I expanded my testing to include longer distances and different connection methods, I stumbled onto something genuinely surprising: PrivateLink connections can actually be faster than direct VNET peering - sometimes significantly so.

When I set out to explore network latency in Azure, I had a simple goal: to understand how physical distance affects performance. After all, we've all heard that farther apart means slower connections. But I wanted specifics - exactly how much slower? And how consistent is that performance? I also wanted to see how long lived TCP connections performed across the Azure network.

I'm sharing what I've learned from my first round of tests, setting a baseline that we can build on later.

A little while ago I set out to find a way to measure the overhead that FQDN filtering places on HTTPS web traffic. I've shared the results here, but I thought I'd take the opportunity to discuss the methodology in a bit more detail.