Content Delivery Network Approach to Improve Web Performance a Review

Since 1999, Voxel has powered the high functioning needs of a demanding client base of operations past offering scalable delivery of high-bandwidth media, applications and content.
www.voxel.net

Panther Express is a global content commitment network provider established in 2005 past the former CEO of DoubleClick, Kevin Ryan, and the co-founder and one-time CTO of DoubleClick, Dwight Merriman.
www.pantherexpress.net

EdgeCast was founded in 2006 past a grouping of successful technology entrepreneurs who take years of experience edifice network infrastructure, web hosting, and awarding delivery products and companies.
www.edgecast.com

IndyNET is a worldwide content distribution and diverse monitoring network headquartered in Christchurch, New Zealand.
indy.internet.nz

Content Commitment Networks assist websites and services to deliver online content in an efficient manner. Since they act transparently behind the scenes, CDNs are often bearding contributors to large online services.

To go a niggling more than insight, nosotros spoke to the CDN providers Voxel dot Net, Panther Express, EdgeCast Networks and IndyNET to get some data on how they work, their perspective on the CDN market and the challenges they face, and what the time to come looks like for CDNs.

Why utilize a CDN?

CDNs seem to exist used everywhere these days, but why is that? Why don't more companies set up their ain infrastructure? Gad Stanislas, Vice President of Panther Limited, explains why CDNs are so widely used.

"Increasingly, companies around the earth view digital content delivery every bit a utility service, much like electricity and telecom," he says. "But few companies have the ability or the want to create their ain CDN infrastructure in order to implement an effective digital content strategy. Every bit a result, they are outsourcing content commitment to CDN providers. For these companies, a CDN provider must offer fast, reliable commitment on terms that are highly flexible and affordable."

This equation of cost, convenience and performance is echoed by the other CDNs likewise. Anthony Citrano at EdgeCast sums it upwardly:

"The ideal CDN provides terminate users with the highest possible performance and quality of content delivery, regardless of the user location or connection to the Net, while at the same time reducing the overall cost of content commitment."

Lots of servers, lots of locations

Much of the reward that CDNs offer comes from serving content from multiple geographical locations, dissimilar traditional hosting providers who normally have just 1 location. Visitors to a site can therefore be routed to a relatively nearby and high-performance "enshroud" of content, which gives less latency and more optimal transfer rates.

While just the number of servers doesn't tell the whole story almost size or functioning (where server specifications can play a huge function, as well as storage solutions and network setups), we thought information technology would exist interesting to go a movie of what is needed to run a CDN. Below are some numbers from the companies we spoke to:

• Panther Express
  800 servers in 22 unlike geographical locations.
• IndyNET Limited
  80 servers in eleven different geographical locations.
• Voxel dot Net
  2000+ servers in xiv dissimilar geographical locations.
• EdgeCast Networks
  Wouldn't disclose the number of servers just say they have 13 different geographical locations.

These locations have to have the same content replicated and synchronized between them (i.e. acting every bit caches of content). The system besides needs to be able to quickly route users to the location closest to them.

Jasper Bryant-Greene, Director of IndyNET, explains more almost how they handle their content distribution: "Static content is delivered to our network via a Remainder API. This content is propagated around the entire network within approximately x seconds. Clients are directed to the closest server via GeoDNS and IP Anycast."

Linux and high-speed web servers

Considering of the specific needs of CDNs they oft use customized software. All of the CDNs we spoke to ran Linux, except EdgeCast who use a combination of Windows and Unix. IndyNET told us that Gentoo Linux is their chief choice but they also apply Debian and Ubuntu.

Panther Limited has their own custom-built web server software, Voxel uses a customized version of Apache, and IndyNET uses the high-functioning Lighttpd spider web server. These networks serve huge amounts of information so it really makes sense for them to utilise software that is optimized for fast content delivery.

Monitoring is crucial

Monitoring is crucial for hosting companies and other online service providers, and it may exist fifty-fifty truer for CDNs due to their strong focus on delivery operation. And it's not all nigh operation, either. Availability is another important factor. If part of a CDN stops working, this needs to be noticed immediately. It is articulate that monitoring is taken very seriously by CDNs.

IndyNET handle all monitoring themselves: "We employ the fantastic open-source monitoring system Nagios both for monitoring our own network and equally a platform for selling monitoring to customers," says Jasper Bryant-Greene.

Panther Express and Voxel, on the other manus, take chosen to use a mix of internal and external monitoring tools and services.

"Our internal monitoring tools run frequent health checks that perform data pulls on examination objects," says Gad Stanislas. "In addition, pings and trace routes are run to measure latency and network health. All data centers are interconnected via a software mesh to make up one's mind real-time data center health in the area of latency, parcel loss and node functioning, which is fed dorsum to our Network Operations Center."

Since reacting to problems is just every bit important every bit detecting them, CDNs benefit from having automated procedures in place to handle at least the most mutual errors. For example, Panther Express merits they tin update their server mappings inside 20 seconds of any issue (and so if a information center goes down or has performance issues, that location can exist excluded from the CDN until information technology works again).

The biggest challenge of running a CDN

Regarding the challenges of running a CDN, there seems to be a consensus that scaling and properly adding chapters is something that CDNs constantly have to deal with.

"Staying far ahead of customer growth curves is our largest challenge," says Zachary Smith, President of Voxel.

According to Gad Stanislas of Panther Express, the challenge is two-fold. "The biggest challenge in running a CDN is capacity planning. The 2d important consideration is gathering critical metrics on system operation."

This is not surprising when yous consider that CDNs are basically selling delivery capacity. The importance of gathering metrics to keep rails of this cannot be understated.

The future of CDNs

The internet as a whole is growing with more than and more than video delivery and other demanding services. How will CDNs adapt and shape themselves to handle the increased demands, or in short, what volition CDNs look similar in the future?

Jasper Bryant-Greene thinks they will look much similar they exercise today, "merely with better technologies for locality, and nodes distributed closer to the customer."

"Larger caches will be required to serve increasingly larger files such as HD video versus standard video files," says Gad Stanislas. "We also anticipate increasing concerns regarding security and content protection."

Zachary Smith believes in service integration with hosting solutions. "CDN services will be an extension of a client'southward hosting infrastructure. It will be up to the hosting integrator to provide a solution that 'just works' to scale their clients."

Nosotros would like to extend a big give thanks you to Jasper Bryant-Greene of IndyNET, Anthony Citrano of EdgeCast, Gad Stanislas of Panther Express and Zachary Smith of Voxel dot Net, who took fourth dimension out of their busy days to speak to u.s.a..

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Source: https://www.pingdom.com/blog/a-look-at-content-delivery-networks-or-how-to-serve-lots-of-content-really-fast/