Case
ESPN CASE:
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1. How many requests from users does ESPN receive each second? Do You think this is a consistent pattern or does it have peaks and valleys? When does it peak?
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ESPN gets over 10.000 requests every second, it means there is a consistent pattern because ESPN services are constantly in high demand by users, creating peaks during a given period of time. A specific moment when a higher amount of people start watching live games such as the Super Bowl, NBA finals and others. I think there are valleys when the events are not running live.
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2. Why does ESPN store personal information and preferences on its databases and how does this personal information complicate the ability of ESPN to respond to requests from users? Why can’t ESPN just use Web page caching to handle the loads?
ESPN offers personalized content (this complicates the process because there is a need for an individual approach to every customer) therefore they store information from all individual requests and customers.
The company has to leverage the same personalization system for ESPN mobile websites and other companies’ websites, there is also an importance of compatibility, where the ESPN platform has to run in any device. To make it possible, they developed a relational database which is called the personalization DB. It uses two main components the GRID and the COMPOSER.
3. How much information on users does ESPN store? Why does this pose a challenge for ESPN? Can’t they just use a standard 1 terabyte hard drive from a PC? Why can’t they use a single PC?
ESPN has to store over 10 million users, on average each user takes over 5 kilobytes of data. That means there is a necessity to store for over 200 gigs of data/information which simply can’t be held by a reasonable number of Java Virtual Machines.
This can’t be held on a simple PC or single hard drive because there is a necessity to code the information, so there is a need for a program that can transform byte codes into computer language so it can be processed easily and faster.
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4. What platforms do ESPN customers use when they access their Web sites, and how does this further complicate ESPN’s processing picture?
ESPN uses the same personalization system for both the computer-based website as their mobile platform and subsequently for 2 other websites (Soccernet and deportes) that ESPN runs.
They do this because they see this as a part of the personalization process. They want to deliver a personalized experience (team preference) to be used throughout all their systems and on any device with which users can access ESPN sites/apps. The key part of this is the DB system that is enough intelligent to deliver the right information to each customer (fan) according to its preferences. When the user request comes into the moment it goes out, ESPN is in single-digit millisecond response time, it means it is extremely fast.
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5. What are the key components in ESPN’s solution? Describe the function of each.
Personalization DB is the system that ESPN uses, this consists of 2 specific components. Namely the Grid and the Composer.
The Grid component that encompasses the specific personalization inside the DB. The reaction of this component is extremely fast, The Grid makes an ultrafast connection time to the personalization DB.
The second part is the Composer, ESPN has hundreds of back-end systems powering its website and the composer, brings them all together. The composer knows perfectly which of ESPN services match to thousands of users.
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6. Why is scalability so important to ESPN?
(5%)
They need to be able to scale their service to ensure a fast response time when a request comes in.
They do this by having 10 servers that they can operate at any given time and regularly working at 5 % of the total capacity.
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This system has an ability to dynamically spin down or up the servers adjusting them to the necessity of the number of requests.
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