When it comes to distributing software over a network, every millisecond may count. In other words, your ability to deliver apps or other software artifacts within fractions of a second can be critical for achieving your software delivery goals.
Unfortunately, sub-second software distribution isn’t always feasible when you’re moving software over the Internet. In some cases, the data centers that host applications are located too far from end-users to guarantee near-instantaneous software delivery.
That’s where Content Delivery Networks, or CDNs, come in. A CDN provides a distributed network of servers that can be used to optimize the distribution of software. Although this is not the only use case for CDNs (which are most often used to speed content downloads from websites), it is a useful technique for organizations that need to distribute software as quickly as possible via the Internet.
Keep reading for an overview of how CDNs work and the role they play in software distribution.
The challenges of long-distance software distribution
The software distribution challenge that CDNs can solve is straightforward: The farther users are located in a geographic sense from the servers that host software, the longer it tends to take for users to download that software.
This is due primarily to the fact that longer geographic distances typically require data to pass across more “hops,” or network segments. Each hop can reduce latency and bandwidth, which means it takes longer for users to receive the software they are downloading. Excessive hops may also lead to packet loss, which requires data to be retransmitted and also leads to delays in transmission. There is also a higher likelihood that data transmissions will fail entirely when you are moving software across a large geographic area because the more network infrastructure your transmission depends on, the greater the risk that one network segment will go down.
The delays associated with sending data over long distances are only a few seconds at most. Sometimes, they are just fractions of a second. To be sure, these delays would not be critical for all software distribution use cases.
However, in some situations, delays of even just fractions of a second can cause problems. For example, imagine that you inadvertently released a buggy version of a containerized application into production, and you need to deploy an updated container to fix it. If it’s an application that’s receiving thousands of requests per second, even a short delay in downloading the container image could have a meaningfully negative impact on your users.
As another example, you may need to deploy a serverless function on demand to accommodate a specific type of application request. If the function isn’t already uploaded to the serverless compute environment, and it takes time to get it there, the application could hang while waiting for the function to move across the network.
A third example of a challenge that could arise when downloading software artifacts across long distances is software developers who are working remotely and need to download source code, application images or artifacts frequently. Although waiting a few seconds for a single download may not be a big deal, the developers’ overall productivity could suffer if they download hundreds of artifacts each day and need to wait on each one. They won’t be able to achieve the same experience or efficiency of development that they could if they didn’t have to wait on data transfers every time they wanted to check out code or pull a container image, for instance.
How CDNs improve software distribution
CDNs solve the problems described above by allowing you to cache copies of software artifacts – like container images or serverless functions – on networks of servers that are geographically dispersed across the globe.
In other words, using a CDN, you could store copies of the software you want to distribute on a number of servers spread across the world. Then, when a team needs to download software, they can pull it from whichever server is located closest to them, leading to faster data transfer.
A second benefit of CDNs for software distribution is that they can improve reliability. When you store all of your artifacts on a single server, or in a single data center, your software distribution channel will break down in the event that the server or data center goes offline, or becomes inaccessible due to issues with its network infrastructure. But with a CDN, you have multiple servers in separate locations hosting your software. If one server becomes unavailable, users can simply pull software from another server in the CDN.
Distribute software faster and more confidently with CDNs
Although you may think of CDNs as a way to improve website performance more than a tool to improve software delivery and distribution, CDNs can do the latter as well.
And while setting up your own CDN and optimizing it for software distribution is a complex task, tools like JFrog Distribution make it easy to take advantage of CDNs for software distribution. JFrog Distribution automatically leverages CDNs and other optimization technologies to speed software distribution across networks you define.