Glossary
DDoS Attack
A malicious attempt to disrupt the normal traffic of a targeted server, service, or network by overwhelming the target or its surrounding infrastructure with a flood of Internet traffic from multiple compromised computer systems.
Example:
During a DDoS attack, a website might become inaccessible as thousands of compromised computers simultaneously send requests, overwhelming its servers and preventing legitimate users from connecting.
Failover
A backup operational mode in which a system automatically switches to a redundant or standby system component upon the failure or abnormal termination of the previously active component.
Example:
If the main server hosting a school's online learning platform crashes, a failover system automatically activates a backup server, allowing students to continue their lessons without interruption.
Fault Tolerance
The ability of a system to continue functioning properly even when one or more of its components fail.
Example:
A self-driving car's navigation system is designed with fault tolerance so that if one sensor fails, it can still safely navigate using data from other sensors.
Higher Costs
A disadvantage of fault tolerance, stemming from the expense of acquiring, maintaining, and powering the additional components required for redundancy.
Example:
Implementing a fault-tolerant system for a small business website might incur higher costs due to the need for multiple servers and specialized network equipment, which can be a significant investment.
Improved Scalability
The ability of a system to handle a growing amount of work or to be easily expanded to accommodate increased demand, often supported by fault tolerance.
Example:
A cloud storage service demonstrates improved scalability by easily adding more servers and storage capacity as its user base grows, allowing it to handle petabytes of data without performance degradation.
Increased Reliability
The quality of a system to perform its intended function consistently and without failure over a specified period, often enhanced by fault tolerance.
Example:
Due to its increased reliability, a well-designed traffic light system can operate continuously for years, ensuring smooth and safe traffic flow without frequent breakdowns.
Increased Resource Requirements
A disadvantage of fault tolerance, referring to the need for more hardware, software, and infrastructure to implement redundant components.
Example:
Building a highly fault-tolerant data center requires significant increased resource requirements, including duplicate servers, power supplies, and cooling systems, making it more complex to set up.
Load Balancing
A method of distributing network traffic efficiently across multiple servers to prevent any single server from becoming overloaded and to improve system responsiveness.
Example:
During a popular online game release, load balancing ensures that millions of players can access the game simultaneously by distributing their connections across many servers, preventing crashes.
Multiple Internet Providers/Wire Channels
A redundancy strategy where an organization uses connections from more than one internet service provider or different physical wire channels to ensure continuous internet access.
Example:
A hospital might subscribe to multiple internet providers to ensure that patient records and critical systems remain accessible even if one provider experiences an outage.
Multiple Paths
A type of redundancy where data can travel through various routes in a network, allowing it to reach its destination even if some paths are unavailable.
Example:
When you stream a video, the data might travel through multiple paths across the internet, so if one server or connection slows down, the stream can reroute to maintain smooth playback.
Reduced Cyberattack Damage
The ability of a fault-tolerant system to minimize the impact and disruption caused by malicious cyberattacks, such as denial-of-service attacks.
Example:
A bank's online services, built with redundancy, can experience reduced cyberattack damage during a DDoS attack, as backup servers can absorb the malicious traffic and keep services running.
Redundancy
The inclusion of extra components in a system that can take over if primary components fail, ensuring continued operation.
Example:
A space shuttle has multiple backup computers for critical systems, demonstrating redundancy to ensure mission success even if one computer malfunctions.