What is application deployment?
Application deployment is the process of releasing and installing software applications or updates. This procedure ensures the software is correctly placed within a specific environment and ready for use by its end-customers. Deployment encompasses several stages, from preparation and configuration to final installation, ensuring that both the software and the underlying system resources are ready for operation. It’s a critical aspect of the software development life cycle, aiming to deliver functional software that meets user needs.
Deployment tasks often include related activities like monitoring for issues post-installation and executing rollback procedures if necessary. These steps ensure reliability while minimizing disruptions. Modern deployment processes leverage automated tools to reduce errors and deliver software earlier. An effective deployment process enhances software reliability and agility, improves productivity for development and operations teams, and ultimately results in more satisfied users.
This is part of a series of articles about software deployment.
A brief history of application deployment
The history of application deployments is deeply entangled with changes in hosting technology, architectural trends, tooling improvements, and software delivery methods. Often, a technology created decades before takes on new relevance thanks to other developments, such as FTP, which was created in 1971 but enjoyed great popularity in the 1990s due to the rise of the World Wide Web. We started with physical on-premises machines, then moved workloads into data centers, virtualized them to make them easier to create and reconfigure, then moved to lightweight isolated containers.
With this in mind, we can view the history of application deployments across the decades:
- Physical manual deployments (1980s and earlier):
Applications were mainly deployed to physical servers and direct physical access was typically needed to perform a deployment. To scale a server, you would have to power it down and upgrade its components. - Remote deployments (1990s):
Though FTP was created in the 1970s, it had its heyday in the 1990s thanks to the world wide web (WWW). Uploading files to servers instead of physically accessing them became one of the most popular ways to deploy applications, with individual file patches often being used to bugfix. - Installer files and scripts (2000s):
Instead of transferring individual files, installer files became a popular way to capture the software artifact and ensure the installation would result in the same software version being installed on each environment. Installer files could be created as part of the Continuous Integration (CI) process. The installer would prompt for variables to allow different configuration settings to be applied to each environment. An alternative solution was to script deployments using batch files to reduce the number of error-prone manual steps. - Continuous Delivery (CD) (2010s):
Continuous Delivery and DevOps encouraged the automation of deployment pipelines so deployments could be made on demand at the push of a button. Deployment automation tools are created to manage deployment-specific features like environment progression and variable management so a single deployment process can be applied to all environments, locations, and customer-specific instances of an application. - Modern software delivery (2020s to present):
While the fuzzy front end of development is seen as the zone of creativity and design, the deployment pipeline is seen as the software delivery factory. CD tools provide advanced features that allow deployment and operations automation across all technology stacks to be managed in one place.
What are the benefits of streamlined application deployment?
Streamlined updates
A well-structured deployment strategy makes deploying new software application versions easier and safer. Deployments can happen on demand without manual intervention, significant downtime, or disruption for the software’s users.
Streamlined deployments let you get feedback earlier and respond to market demands. The ability to deliver timely enhancements and bug fixes makes your software more competitive and increases user satisfaction. Modern deployments use automation to increase throughput and stability, which were traditionally seen as trade-offs.
Stronger security
When you deploy infrequently, dependencies remain out of date for longer, which exposes you to threats based on known vulnerabilities. When you deploy often, you can address vulnerabilities sooner, quickly promote changes to mitigate cyber threats, and swiftly address security concerns.
You can include security testing as part of your deployment pipeline, using static and dynamic security testing tools to automate the process. Including security earlier in your software delivery process reduces the potential for attacks and keeps your data safe.
Enhanced visibility
Modern application deployments bring a new level of visibility into the state and history of environments and changes to the deployment process. Dashboards provide an overview of which versions are deployed to each environment and reports track key deployment metrics to help teams improve their deployment pipeline and software delivery performance.
CD tools provide audit trails for actions and changes to simplify audits and reduce the regulatory and compliance burden on teams.
The application deployment process
1. Strategic planning
Strategic planning involves defining objectives, identifying resources, and creating a roadmap for deployment. This phase ensures that all stakeholders are aligned on the goals and timelines, reducing the risk of misunderstandings and delays. Effective strategic planning considers the target environment, potential risks, and mitigation strategies, setting the stage for a smooth deployment.
Planning includes selecting appropriate tools and processes, enabling a tailored approach to deployment. By anticipating challenges and preparing contingencies, organizations can confidently navigate complexities, ensuring the deployment process is orderly and efficient. Strategic planning lays the groundwork for a successful deployment and enhances collaboration and communication among the deployment team.
2. Development and testing
Developers should build and refine the application in small batches, with early feedback from a fast automated test suite. Changes should be committed to version control several times a day, with tests to validate that the application remains deployable at all times.
A test environment reflective of production should be used for acceptance testing with the same artifact and deployment process used for pre-production and production deployments. This ensures the deployment process is tested as frequently as the application.
3. Automated builds
Automated builds are critical to modern deployment strategies, compiling, linking, and packaging software code. Continuous Integration (CI) tools like Jenkins or GitHub Actions ensure all code changes are automatically built and tested.
Automated builds reduce manual labor, minimize errors, and facilitate frequent releases, allowing for rapid iteration and feedback. Automation mitigates the risk of human error and ensures that every build is done the same way, enhancing overall stability.
4. Testing configurations and scripts
Your configuration management and deployment process should be tested as regularly as your application. This involves using the same deployment process or configuration scripts for all environments and checking that environment-specific settings are applied correctly.
You can increase the value of your validation steps by making sure your staging environment mirrors your production setup. For example, failing to load balance requests in staging will hide bugs that only happen when different instances serve a sequence of requests.
5. Rollout and validation
Rollout and validation are the phases where the application is deployed to the production environment and its performance is assessed in real time. During rollout, teams follow a predefined plan to deploy the application efficiently, often using tools to manage and automate the process. Validation involves monitoring the application to verify that it functions correctly and meets performance expectations. Any issues are promptly addressed to ensure minimal impact on users.
Effective rollout strategies, such as phased or canary deployments, can minimize risk by gradually introducing changes and observing their effects. Once the rollout is complete, validation through testing and monitoring ensures the application is stable and performs under real-world conditions. This approach ensures that post-deployment issues are quickly identified and resolved, maintaining high service quality and reliability.
6. Ongoing performance monitoring
Performance monitoring is crucial for maintaining the health and efficiency of the deployed application. It involves continuous tracking of application metrics such as response times, error rates, and resource usage. Monitoring tools like Datadog, Nagios, or Prometheus help teams gain real-time insights into the application’s performance, quickly identifying and addressing potential issues before they impact users.
You can use performance data to help with capacity planning and make decisions about scaling. You can analyze trends and patterns in application usage to make more informed decisions about resource allocation. Effective monitoring will help you keep applications stable, responsive, and reliable. When you have a system problem, finding out before it impacts users can help reduce its impact.