Understanding Edge Caching Content Delivery

Overview

A Content Delivery Network (CDN) is a system of servers deployed across a large geographic area that operate together to deliver content to end-users via the Internet. The nodes on the CDN work together to quickly and efficiently satisfy end-user requests for the Internet-based content.

Hostway currently manages multiple data centers worldwide, providing a strong global footprint for our CDN product: Edge Caching. When a site visitor downloads content from a Web site, the Edge Caching servers select the best location and work in parallel to deliver the content from our multiple cache servers. This method, called parallel retrieval, allows Hostway to utilize multiple Edge Caching servers to drastically reduce the amount of time it takes to deliver the content.

Technology

Hostway’s Edge Caching solution is based on multiple patent-pending technologies. Our distributed multiple name servers select the best server location for content distribution based on: end user location, network status and other pertinent information.

Hostway measures the network speed from tens of thousands of locations worldwide, documenting the results in our databases. The fastest routes are determined and implemented into our CDN. Once the best data center location is determined and the best cache servers are selected, the objects are retrieved in parallel depending on the content types.

Hostway's Edge Caching solution provides three primary benefits:

High Availability
Customer content is distributed worldwide to our CDN cache servers. If the best servers fail or a disaster occurs in that data center area, the content files are safely channeled through the second best cache servers and to the end-user. Even if the primary server fails, the average downtime should be negligible, oftentimes, less than a minute.

Scalability
The Edge Caching CDN solution is scaled over multiple servers and an extremely large bandwidth capacity. The bandwidth capacity limit can be easily adjusted, as each client has different needs. For example customers can increase the guaranteed bandwidth usage limit from 10mbps to 1Gbps with a single request, without any modification from their side. Such an increase might also be applicable if such an expansion is during a short period. Even if the customer’s bandwidth usage increase is unplanned, like DDoS, temporary burst requests can be processed.

Improved Speed
The Edge Caching servers that provide the fastest delivery time are determined based on user location and network status by our patent-pending technologies. Also, the process of parallel retrieval can further improve site performance.

Add-On Features

Further features can be customized to each customer:

Protection of Cached Objects

If the cached objects are protected at the origin server, they should be protected on the cache servers as well. For example, some high-quality movies may be shown only to paying users. The cache servers check the authentication/authorization in tandem with the origin server, thus providing the same level of security as the origin server.

Pulling/Pushing Content
In general, the content is retrieved when an actual end-user’s requests arrive at the cache server level. This method, called the “Pull” method, can save bandwidth and storage costs.
If the highest level of consistency is required, the content can be pushed onto our publish servers whenever content is added or modified. Using this “Push” method, the content is distributed onto our Edge Caching cache servers in real time.

Quality of Service (QoS)
Edge Caching allows customers to apply additional end-user settings to the CDN platform. Hostway can assign additional application-level information to place customers in different tiers. For example, the requests from GOLD class users (extracted from a cookie value) can be redirected to a high-quality cache server every time they search the site.

Management

Customers can manage and monitor their sites and content within the Edge Caching management tool, SiteControl. These are the main SiteControl components:

Home
This section includes usage summary and billing information.

CDN Status
Provides live status updates of all datacenter locations.

Stats and Usage
Basic Web analytics tool and statistics are housed here. A client density feature details where most of the traffic is coming from worldwide. Billing information based on the bandwidth used is also shown in this screen.

CDN Content
Content management functions, such as purging cached objects, are available here.

Real-Time Monitoring
Real-time usage such as current worldwide aggregated bandwidth usage, number of sessions, number of requests and other information are all gathered and provided for your monitoring.

Conclusion

The ability to deliver online content quickly and efficiently is imperative to growing any business with an online presence. Hostway’s Edge Caching Content Delivery Network solution helps expand a company’s global footprint, ensuring that customers visiting our clients’ sites experience faster page download times for content of all types.

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