Essential Systems Design Concepts: Key Insights for Developers
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Chapter 1: Introduction to Systems Design Concepts
In this series, we delve into 100 critical systems design concepts that every developer should be familiar with. These concepts are vital for creating systems that are efficient, fault-tolerant, and scalable. To enhance clarity, I will break these concepts into several posts. If you are new to programming or Python, consider checking out my book, The No Bulls**t Guide To Learning Python for a straightforward introduction.
You can find links to the previous parts below:
Chapter 2: Key Concepts 21-30
- Latency
Latency refers to the time taken for an operation to be completed within a system. For instance, the duration between clicking the ‘Login’ button and being redirected to your Facebook homepage illustrates the latency of Facebook’s servers.
- Throughput
This term denotes the volume of data transmitted over a network in a given timeframe (measured in bits per second or data packets per second).
- Bandwidth
Bandwidth is the maximum amount of data that can be transmitted over a network within a specified period.
- Consistency
In the context of distributed systems, consistency entails receiving predictable outcomes when reading, writing, or updating data across various nodes.
- Availability
Availability represents the likelihood that a system will function as intended, commonly referred to as uptime.
- Downtime
This term indicates the duration during which a system is not operational.
- Availability in Nines
Availability is quantified in "nines." For example, a system with 90% availability experiences 36.53 days of downtime annually, while a system with 99% availability has 3.65 days of downtime each year. Highly available systems are defined as those achieving 99.999% availability (five nines), resulting in only 5.26 minutes of downtime per year.
- Reliability
Reliability is the probability that a system will perform its intended function correctly over a specified period.
- Redundancy
This concept involves duplicating essential components of a system, like a web application’s database, to enhance reliability and eliminate single points of failure.
- Service-Level Agreement (SLA)
An SLA outlines the service expectations between a provider and a customer regarding service level objectives (SLOs), which include performance metrics. For instance, the SLA we have with Amazon for storing image data on AWS S3 emphasizes high availability and security.
Thanks for reading! Stay tuned for the next part of the series.
The first video provides a brief overview of 20 essential system design concepts explained in just 10 minutes.
The second video discusses how to successfully pass every system design interview using the UNDER method.