Photo by Sebastien Gabriel

Now Delivering. Globally. 🌎 🌍 🌏

Simplecast’s quest for faster (and better) worldwide delivery

My perspective on the world is inescapably tied to the specific location I live. As a web developer, I’m especially aware of the importance location has on the products I build and while New York state is clearly the best place to live 😉 😎, the reality is, Simplecast users and listeners are spread across the globe.

Among the many changes we’re implementing at Simplecast, we’re excited to detail our recently upgraded Content Delivery Network (CDN) built on the StackPath infrastructure.

On the internet, there are many factors that play into the speed of a user’s connection. Some of the most important factors are transfer speed, file size, and distance.

Transfer speed refers to the speed at which files are delivered to the end user. There are many points along a file’s journey that affect the speed, but it’s most often limited by the internet service provider (ISP). When someone thinks of having “fast internet” they are referring to the speed at which files are transferred from their ISP.

While there are steps to ensure we do not hinder speed — and we most certainly have taken those steps — increasing transfer speed is mostly limited to what is available to the end user.

File size also affects speed of delivery. The larger the file, the longer it will take to download. As you might have guessed, Simplecast deals mostly with audio files and it’s imperative that we deliver a file that is as optimized as possible, without sacrificing quality. Currently, for the spoken word, we transcode audio to 128kbps in the MP3 format.

While people naturally think that further distance means a longer path to travel, it turns out that physical distance isn’t a huge factor anymore. Technology has improved enough that it doesn’t hinder the speed of light, which last I checked, is pretty fast.

What does matter regarding distance are the bottlenecks that occur between the origin and destination of the file being delivered. The further the distance, the more likely that latency, network congestion, packet loss, and network hops will occur. Decreasing the distance between origin and destination is what CDNs are all about.

Long Distance Relationships 📍

Our current origin servers reside on the East Coast of the United States of America. Every original file served to the world is sourced from this point. If you break down Simplecast’s traffic worldwide you will see that our requests look something like this:

• 28% outside the U.S.
• 72% within the U.S.

In the U.S., only 40% of our traffic comes from eastern regions. This means that 60% of our data travels quite some distance. With all the various speed factors mentioned above, it’s guaranteed that if we served up all our traffic from our origin servers there would be some seriously slow transfer rates—and that’s just in the US of A.

Whether we liked it or not, we were forcing our podcasts into a long distance relationship with their listeners.

Enter the CDN 🗺

Not all CDNs are created equal. We found this out the hard way. After researching multiple global providers, we ultimately ended up choosing StackPath (formerly Highwinds), as their features and capabilities are downright amazing. If you are looking for a new CDN you should consider the following benefits (and StackPath of course) and how they compare to your current CDN. They’ve worked wonders for Simplecast.

Cache Miss Ratio

Do you know your cache miss ratio for your CDN? If you don’t, you’d better go find out. The cache miss ratio is the percentage of requests that are not cached and have to be sourced from the origin servers.

Origin Shielding

The less a file has to be sourced from the origin server, the better. Origin shielding refers to an extra caching layer between the CDN edge servers and your origin server. The shield helps offload the origin server and speed up cache miss responses so that file requests are delivered from the cache as much as possible.

Our previous CDN did not have origin shielding and we had a 25% cache miss ratio 😱 on their infrastructure. These issues were reflected in our ever increasing data transfer volume.

Points of Presence (PoPs)

To deliver files quickly and globally, CDNs house servers across the globe to serve files from the point of presence nearest the end user. StackPath has PoPs in North America, South America, Europe, Asia, and Oceania (Australia) and are fully owned and operated by StackPath. While most CDNs operate globally, few actually own their equipment. This ensures that each of StackPath’s data centers are running the best network and fastest equipment possible.

Byte Range Requests & Segmented Downloads

On top of reducing distance and providing better caching, byte range requests allow for smaller chunks of data to be requested and consequently smaller payloads to be delivered.

Application Programming Interface (API)

Many CDNs have an API, but StackPath’s API allows for immediate resource purging. This was extremely important for us as it allows us to keep all our files in cache and only purge files when they change. One of the biggest wins for us was related to Simplecast’s new real-time RSS feed uncaching.

So... If you’ve made it this far I applaud you, because it’s time to bring this article back to you, both the podcaster and the listener. You are now experiencing faster file delivery speeds — to and from Simplecast — with the largest speed gains for users outside of the US.

You can rest assured that the delivery of your content will never get in the way of your audience listening to your shows — regardless of where they live.

🔊 ⚡️ 🌎 🌍 🌏