Resilient Foundation: Design for Error, Build for Stability
Building a resilient foundation for your software is essential to ensure stability and reliability. Learn how to design for error and build for stability.
Resilient Foundation: Design for Error, Build for Stability. A Guide to Building Stable Software.
Author: Maarten
Published on: April 13, 2024
Introduction
In the fast-paced world of software development, building stable and reliable software is essential to meet the demands of modern applications. However, achieving stability and reliability is no easy feat, as software systems are inherently complex and prone to errors. To address these challenges, developers must adopt a proactive approach to error handling and build a resilient foundation that can withstand unexpected failures and disruptions. In this exploration, we'll delve into the importance of resilience in software development and strategies for creating a solid foundation that withstands the majority of challenges.
In this article, we'll explore on how to design for error, work with zero trust architecture, and build for stability. By adopting a proactive approach to error handling and building a solid foundation, developers can create software that is more resilient, stable, and reliable. By designing for error and building for stability, developers can create software that is better equipped to handle unexpected disruptions and recover gracefully from failures.
What is Resilience?
Resilience is the ability of a system to adapt to changing conditions and recover from failures. In the context of software development, resilience refers to the capacity of a software system to withstand unexpected disruptions and continue to function effectively under adverse conditions. Resilience is a critical aspect of software development, as it ensures that applications remain stable and reliable in the face of errors and failures.
The Importance of Resilience in Software Development
In the context of Software Development, resilience refers to the ability of a system to adapt to changing conditions and recover from failures. A resilient system can withstand unexpected disruptions and continue to function effectively under adverse conditions. Resilience is a critical aspect of software development, as it ensures that applications remain stable and reliable in the face of errors and failures.
Whereas traditional software development approaches focus on preventing errors and failures, resilient software development embraces the inevitability of errors and failures and seeks to build systems that can recover quickly and gracefully from disruptions. By designing for error and building for stability, developers can create software that is robust, reliable, and capable of withstanding the challenges of modern applications.
So to speak, expect the unexpected and prepare for it.
Designing for Error
One of the key principles of resilient software development is designing for error. Instead of treating errors as exceptional events, developers should consider them as an integral part of the software development process. By anticipating potential errors and failures, developers can design systems that are better equipped to handle unexpected disruptions and recover gracefully from failures.
When designing for error, developers should consider the following strategies:
- Input Validation: Input validation is a critical aspect of building secure applications. By validating user input, developers can prevent common security vulnerabilities, such as SQL injection, cross-site scripting, and command injection. A common approach to input validation is to use a validation library, such as Joi or express-validator. By implementing input validation, developers can create applications that are more secure, reliable, and less vulnerable to attacks.
- Fail Fast: Fail fast is a software development principle that encourages developers to detect errors as soon as possible and fail quickly to prevent further damage. By failing fast, developers can identify issues early in the development process and address them before they escalate into more significant problems.
- Graceful Degradation: Graceful degradation is a design strategy that involves building systems that can continue to function, albeit with reduced functionality, in the event of failures. By implementing graceful degradation, developers can ensure that applications remain operational even when certain components fail.
- Fault Isolation: Fault isolation is a design technique that involves isolating errors and failures to prevent them from spreading to other parts of the system. By isolating faults, developers can contain errors and minimize their impact on the overall system.
- Error Recovery: Error recovery is the process of restoring a system to a stable state after a failure or disruption. By implementing error recovery mechanisms, developers can ensure that applications can recover quickly and resume normal operation after unexpected failures.
By designing for error, developers can create software that is more resilient, stable, and reliable. By anticipating potential errors and failures, developers can build systems that are better equipped to handle unexpected disruptions and recover gracefully from failures.
How does Designing for Error Translate to Building for Stability?
Designing for error is a critical aspect of building a resilient foundation for software. By anticipating potential errors and failures, developers can create systems that are better equipped to handle unexpected disruptions and recover gracefully from failures. However, designing for error is only one part of the equation. To build a stable and reliable software system, developers must also focus on building for stability.
Building for stability involves implementing robust design choices, best practices, and architectural patterns that promote stability and reliability. By adopting a proactive approach to error handling and building a solid foundation, developers can create software that is more resilient, stable, and reliable.
Some key strategies for building for stability include:
- Modular Design: Modular design involves breaking down complex systems into smaller, more manageable components. By designing systems in a modular fashion, developers can isolate errors and failures, contain disruptions, and minimize their impact on the overall system.
- Redundancy: Redundancy is the practice of duplicating critical components to ensure that systems remain operational in the event of failures. By implementing redundancy, developers can create systems that are more resilient and capable of withstanding unexpected disruptions.
- Monitoring and Alerting: Monitoring and alerting are essential practices for detecting errors and failures in real-time. By implementing monitoring and alerting mechanisms, developers can identify issues early and respond quickly to prevent further damage.
- Automated Testing: Automated testing is a critical aspect of building stable software. By automating the testing process, developers can identify errors and failures early in the development process and ensure that applications meet the desired quality standards.
- Continuous Integration and Deployment: Continuous integration and deployment (CI/CD) is a software development practice that involves automating the build, test, and deployment process. By adopting CI/CD, developers can accelerate the development cycle, reduce errors, and ensure that applications are stable and reliable.
- Documentation: Documentation is a critical aspect of building stable software. By documenting design choices, architectural patterns, and best practices, developers can ensure that applications are well-documented and maintainable.
Some of the strategies and principles mentioned above are not exhaustive, but they provide a solid foundation for building stable and reliable software. By adopting a proactive approach to error handling and building for stability, developers can create software that is more resilient, stable, and reliable. Read more about the Tripple Benefit Code and how it can help you build stable software.
Zero Trust Architecture/Policies
Zero Trust is a security model that assumes that threats exist both inside and outside the network. Zero Trust architecture is a security model that requires strict identity verification for every person and device trying to access resources on a private network, regardless of whether they are sitting within or outside of the network perimeter.
Zero Trust architecture is based on the principle of "never trust, always verify." By implementing Zero Trust architecture, organizations can reduce the risk of security breaches and ensure that applications remain secure and reliable.
This principle in architecture is very important to ensure that your platform and applications are secure and reliable. Imagine a scenario where a user can access a part of your application without being authenticated, this can lead to security vulnerabilities and data breaches. By implementing Zero Trust architecture, you can ensure that all users and devices are authenticated and authorized before accessing resources on your network. By implementing Zero Trust architecture, you can create a secure and reliable software system that is better equipped to withstand security threats and protect sensitive data. Zero Trust architecture is a critical aspect of building secure and reliable software. Input validation is part of the Zero Trust architecture, by validating user input, the system can be sure that the input is safe and secure. Input validation by itself is not enough to ensure a zero trust architecture, but it is a critical aspect of building secure and reliable software. Using the principle of "never trust, always verify", developers must ensure that each request is verified and authenticated before moving forward with making changes on the system. This can be done by using JWT tokens, OAuth, or other authentication mechanisms.
A common mistake is that developers trust that the 'private' API will not be called by unauthorized users. This is a mistake, as the API can be called by anyone who knows the endpoint. By implementing Zero Trust architecture, developers know that each request is from anyone on the internet and should be verified and authenticated.
What does it look like in practice?
Designing for error leads to building for stability. By adopting a proactive approach to error handling and building a solid foundation, developers can create software that is more resilient, stable, and reliable. Let's take a look at an example to illustrate how designing for error translates to building for stability.
Let's use an example of an API endpoint that retrieves user data from a database. When designing the API endpoint, developers should consider potential errors and failures that may occur, such as network timeouts, database connection errors, or data validation issues. By anticipating these errors and failures, developers can design the API endpoint to handle these scenarios gracefully and recover quickly from disruptions.
This example may look like the following:
app.get("/users/:id", async (req, res) => {
try {
// We do not know the userId, so lets validate it first
if (!isValidUserId(req.params.id)) {
res.status(400).json({ error: "Invalid user ID" });
return;
}
const user = await getUserById(req.params.id);
if (!user) {
res.status(404).json({ error: "User not found" });
return;
}
res.json(user);
} catch (error) {
console.error("An error occurred while retrieving user data:", error);
res.status(500).json({ error: "An unexpected error occurred" });
}
});By validating the user input, the API endpoint can prevent invalid requests from reaching the database, reducing the risk of data corruption or security vulnerabilities. Additionally, by handling errors gracefully and providing informative error messages, the API endpoint can recover quickly from disruptions and maintain a positive user experience.
This however is not enough to build a stable software. To build a stable applications, developers must also account for other factors such as scalability, performance, security, and maintainability. By adopting a holistic approach to software development and focusing on building for stability, developers can create software that is more resilient, stable, and reliable.
How to implement stability for your applications?
Building software that is designed to error is a critical aspect of creating stable and reliable applications, however in the case of building for stability, developers must also focus on the aspects outside the codebase.
How to implement load balancing?
Load balancing is a critical aspect of building stable and reliable applications. By distributing incoming traffic across multiple servers, load balancing can prevent individual servers from becoming overwhelmed and ensure that applications remain responsive and available.
A common approach to load balancing is to use a load balancer, such as NGINX. Load balancers can distribute incoming traffic across multiple servers, ensuring that no single server becomes a bottleneck. By implementing load balancing, developers can create applications that are more scalable, reliable, and capable of withstanding high traffic loads.
How to implement caching?
Caching can lead to more performant applications by storing frequently accessed data in memory or on disk. By caching data, applications can reduce the number of requests to the database, improve response times, and enhance the overall user experience. A common approach to caching is to use a caching layer, such as Redis or Memcached. By implementing caching, developers can create applications that are more performant, scalable, and responsive.
How to implement monitoring and alerting?
Monitoring and alerting are essential practices for detecting errors and failures in real-time. By implementing monitoring and alerting mechanisms, developers can identify issues early and respond quickly to prevent further damage. A common approach to monitoring and alerting is to use a monitoring tool, such as Prometheus or Grafana. By implementing monitoring and alerting, developers can create applications that are more stable, reliable, and capable of withstanding unexpected disruptions.
Monitoring for errors is useful, know when a 500 error occurs, or when a service is down. Alerting like this can be done with tools like Sentry in combination with Slack.
How to implement automated testing?
Automated testing creates a safety net for developers to ensure that the codebase remains stable and reliable. By automating the testing process, developers can identify errors and failures early in the development process and ensure that applications meet the desired quality standards. A common approach to automated testing is to test in the CI/CD pipeline. By implementing automated testing, developers can create applications that are more stable, reliable, and capable of withstanding unexpected disruptions.
How to implement continuous integration and deployment?
By enabling continuous integration and deployment (CI/CD), developers can automate the build, test, and deployment process. By adopting CI/CD, developers can accelerate the development cycle, reduce errors, and ensure that applications are stable and reliable. A common approach to CI/CD is to use a CI/CD tool, such as Jenkins or GitLab CI. By implementing CI/CD, developers can create applications that are more stable, reliable, and capable of withstanding unexpected disruptions.
A common thing said when talking about CI/CD is: "If it hurts, do it more often.", this means to automate the things that are painful to do manually.
How do I ensure my application is secure?
No application is 'secure' out of the box. Security is a process, not a product. By implementing security best practices, such as input validation, authentication, and authorization, developers can create applications that are more secure and less vulnerable to attacks. A common approach to security is to follow the OWASP Top 10 guidelines. By implementing security best practices, developers can create applications that are more secure, reliable, and capable of withstanding security threats.
How to achieve complete zero trust architecture?
Zero Trust architecture is a security model that requires strict identity verification for every person and device trying to access resources on a private network, regardless of whether they are sitting within or outside of the network perimeter. By implementing Zero Trust architecture, organizations can reduce the risk of security breaches and ensure that applications remain secure and reliable. A common approach to Zero Trust architecture is to use identity and access management (IAM) tools, such as Okta or Auth0. By implementing Zero Trust architecture, developers can create a secure and reliable software system that is better equipped to withstand security threats and protect sensitive data.
Input Validation
Input validation is a critical aspect of building secure applications. By validating user input, developers can prevent common security vulnerabilities, such as SQL injection, cross-site scripting, and command injection. A common approach to input validation is to use a validation library, such as Joi or express-validator. By implementing input validation, developers can create applications that are more secure, reliable, and less vulnerable to attacks.
Bad Code Example
This example below shows a basic, very insecure flow. It does not validate the fields used by the service, but also sends critical information to a potential attacker. This is a basic example, but it shows the importance of input validation.
app.post("/login", async (req, res) => {
const { username, password } = req.body;
const user = await getUserByUsername(username);
if (!user) {
res.status(400).json({ error: "User not found" });
return;
}
if (user.password !== password) {
res.status(400).json({ error: "Incorrect password" });
return;
}
return res.status(200).json({ status: "ok", user });
});Good Code Example
This example below shows a basic flow, but is more secure. It shows to validate the fields used by the service, but does not send critical information to a potential attacker. This is a basic example, but it shows the importance of input validation.
app.post("/login", async (req, res) => {
try {
const { username, password } = req.body;
if (!username || !password) {
res.status(400).json({ error: "Username and password are required" });
return;
}
if (!isValidUsername(username) || !isValidPassword(password)) {
// Do not expose if the user exists or not and do not expose the error
res.status(400).json({ error: "Invalid request" });
return;
}
const user = await getUserByUsername(username);
if (!user) {
// Do not expose if the user exists or not
res.status(400).json({ error: "Invalid request" });
return;
}
if (!comparePassword(password, user.password)) {
// Do not expose if the password is incorrect
res.status(400).json({ error: "Invalid request" });
return;
}
return res.status(200).json({ status: "ok" });
} catch (error) {
console.error("An error occurred while logging in:", error);
res.status(500).json({ error: "An unexpected error occurred" });
}
});Above is just a very simple example using Typescript and Express, but it shows the importance of input validation and how to handle it more securely than the basic example. It also shows how to design for error and build for stability.
Safety is not always in the code
When making software, the most important part of the application is its users. Users are the ones that use the application and can make or break the application. By ensuring that the application is secure, reliable, and stable, developers can create software that is more resilient and capable of withstanding the challenges of modern applications. Safety therefore is not always in the code, but also in the people using the application. By providing a zero trust architecture, designing for error, and building for stability, developers can create software that is more secure, reliable, and capable of withstanding security threats and protect sensitive data.
But as mentioned before, security is a process, not a product. This includes that the system must not leak sensitive information such as if a user exists or not, or if the password is incorrect. By providing a generic error message, the system can prevent attackers from knowing if they are close to a successful attack.
Conclusion
When designing for error, you can prevent a lot of issues from happening. By building for stability, you can ensure that your application is reliable and robust. By combining these two approaches, you can create software that is more resilient, stable, and reliable. By adopting a proactive approach to error handling and building a solid foundation, developers can create software that is better equipped to handle unexpected disruptions and recover gracefully from failures.
In conclusion, designing for error and building for stability are essential aspects of creating stable and reliable software. By adopting a proactive approach to error handling and building a solid foundation, developers can create software that is more resilient, stable, and reliable. By anticipating potential errors and failures, developers can build systems that are better equipped to handle unexpected disruptions and recover gracefully from failures.
By focusing on resilience in software development, developers can create software that is capable of withstanding the challenges of modern applications and delivering a positive user experience. By designing for error and building for stability, developers can create software that is more resilient, stable, and reliable.
In the end, the goal is to create software that is robust, reliable, and capable of withstanding the challenges of modern applications. By adopting a proactive approach to error handling and building a solid foundation, developers can create software that is more resilient, stable, and reliable. By designing for error and building for stability, developers can create software that is better equipped to handle unexpected disruptions and recover gracefully from failures.
Remember, expect the unexpected and you will be prepared for it.
Here are some key takeaways:
- Resilience is the ability of a system to adapt to changing conditions and recover from failures.
- Designing for error involves anticipating potential errors and failures and building systems that can recover gracefully from disruptions.
- Building for stability involves implementing robust design choices, best practices, and architectural patterns that promote stability and reliability.
- Zero Trust architecture is a security model that requires strict identity verification for every person and device trying to access resources on a private network.
- By adopting a proactive approach to error handling and building a solid foundation, developers can create software that is more resilient, stable, and reliable.
- Safety is not always in the code, but also in the people using the application. Leaking sensitive information can lead to security vulnerabilities and data breaches.
By designing for error and building for stability, developers can create software applications that are more resilient, stable, and reliable.