What Is a Hotfix? Software Patches Explained

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Bugs, coding errors that cause unexpected behavior, come from a variety of places. Defects might arise when customers report them through the support team, through QA test execution or when developers find issues while coding. Teams typically log bugs into a tracking system. They then prioritize and fix them for each release. Testers assess bug fixes individually, then place them into a regression testing suite that’s executed before the release. Developers also may create unit tests within the code to automatically test their bug fixes.  

Hotfix benefits

Exercise caution with hotfixes. If you must apply these types of software patches, consider these hotfix benefits: 

• Remediate critical bugs: A hotfix is applied to fix high-severity bugs — like those impacting major functionality or security of an app — that require immediate fixing.
• Speed: Hotfixes are done quickly instead of waiting for the next planned release, and without creating app downtime or the need to reinstall the app.
• Improve user experience: The fast nature of these rapid software patches not only corrects the short-term issue, but can improve performance and usability.  

Hotfix challenges

Hotfixes may help in the short term, but they raise considerations and longer-term problems. Before you apply these software patches, consider hotfix challenges like:

• Long-term loss of quality: To boost customer satisfaction, some companies rely too heavily on hotfixes. This can make the problem worse by lowering the app quality over time. One hotfix often follows another until the application is patched or duct-taped together. A codebase packed with hotfixes is very difficult to maintain.
• Impromptu planning: Most organizations aren’t suited to meet the significant and quick  planning required to promote solid hotfixes. Engineers must move fast to release hotfixes, often adding to future quality issues. 
• SDLC disruptions: Hotfixes can become recurring fire drills. Product owners, developers and testers must create an approach to manage hotfixes and remove defects without adding bugs. These software patches disrupt the flow of daily work. They also distract from developing newer features on the app in question, or working on other projects.
• Codebase destabilization: Because of their rapid-fix nature and sped-up testing cycles, these software patches often introduce unstable code to the app codebase.

“There’s a lot to be gleaned from observing organizations in hotfix hot water. Some hotfix-reliant clients contribute to dev team fatigue, as individuals are pulled away from improving the feature set of the app in question, or other strategic projects. The current sprint can suffer errors which require yet another hotfix. This hotfix cycle should tip off organizations to take a hard look at their SCLC.”

– Hamish Sherlock, VP, Solution Consulting, Applause

Typical hotfix timeline

Software developers and testers work in a sprint, a planned set of work, to create new features and bug fixes for each release. When a hotfix occurs, the organization compiles the bug details. Developers and testers then discuss a plan for a fast code-and-test routine. Other work stops until the hotfix is coded, tested and deployed. 

Once the bug is coded, it undergoes unit testing. After, the fix gets deployed to the test server. The QA professional assigned to the bugfix validates it in the test server. If it passes, it is deployed to a secondary test server, usually called Staging — though is sometimes deployed straight to Production. Depending on the nature of the software patch, such as whether it is a major security vulnerability or critical functionality defect, the QA tester typically runs a basic smoke test against all functionality and the bug fix in production. Testing within a live Production server carries significant risk. That’s why hotfix testing is often only done up to the Staging server.  

Once the hotfix is deployed and live, the team returns to its sprint or release work. 

The risk of hotfixes and their cyclical nature

Hotfixes interrupt the release flow for both development and testing teams. It’s distracting to constantly shift work tasks and priorities, yet software development organizations get into the habit of continuously releasing these software patches.

As mentioned, constant hotfix releases destabilize the Production server. They also introduce new bugs that only cause more software patches. Once a company is on the hotfix carousel, it’s difficult to get off. But, if it doesn’t stop, the organization risks creating a codebase that is layered with hotfix code that is difficult or impossible to support. The regular release cycle is constantly interrupted, code destabilizes and supporting the codebase becomes trickier every day.

The ultimate result is missed release deadlines. Additionally, the application suffers from poor overall quality. Customers might like quick fixes, until they cause more quick fixes. At that point, the lack of consistency and chaos caused by these software patches might prompt the customer to lose trust in the application. This carries reputational and revenue damage for the business. 

Keys to avoiding hotfixes 

The surest method of avoiding hotfixes is increasing the software testing scope, breadth and depth. Plan for full regression testing against a Staging server that mirrors the Production server exactly. Additionally, do tests against all back-end messaging, database, API and other dependent connections. 

Test data must represent real production data at least in type and structure. Testing must encompass configuration settings or customizable settings. Test servers must run the same active connections that Production does rather than rely on simulated connection processing or simulated data loading.

Other keys to avoid hotfixes include to: 

• improve user story or requirements documentation with actual functional details;
• improve design or consider using prototypes before coding;
• create time for unit test development;
• use automated integrated unit tests before each code deployment;
• consider switching to continuous integration and continuous deployment;
• create more in-depth documentation within development and testing.

How to implement a hotfix step by step 

During a tester’s career, they will likely test thousands of hotfixes. Though software patches depend on the specific systems, consider these general considerations before implementing a hotfix:

• Identify the issue. Is it a system malfunction, a critical bug? You must assess the severity and ask yourself if the hotfix is needed now instead of waiting for the next scheduled update. This is a risk vs. vulnerability exercise. 
• Develop a quick solution. Address the most targeted hotfix for the issue. Expanding focus only opens up more risk.
• Communicate the details. Inform the developers coding the fix, including the bug itself and the expected software patch result.
• Review the expected functionality. Guide the testing and product team(s) in determining what they can and can’t test. 
• Make a checklist of all items to be tested. Include any integrated functionality that is affected by the defect. Checklists are fast to create and easy to follow during testing, ensuring all relevant items are tested. They also provide base documentation for any test cases written post-deployment.
• Test the hotfix in a staging or test environment. The environment should closely mirror the production environment before deployment. As time permits, test as extensively as possible. 
• Back up the current system state. Make sure all related components are also considered. 
• Align your expectations. Confirm that all persons involved, including internal and external stakeholders, understand that you’re about to apply the hotfix. Communicate any disruptions expected from these software patches. 
• Deploy the hotfix. If possible, deploy while the system is still running. This might mean deploying code changes without stopping services, for example. If the system has more than one server, a rolling application of the software patch may reduce overall impact risk.
• Regression test around the defect. Determine what other functionality might be impacted by the hotfix correction. Test as many associated features as possible. Once hotfix testing is completed, add the test steps to the regression or smoke test suite for future execution.  
• Monitor the system. Make sure you understand how the system runs after the software patch.
• Document the specifics of the hotfix. Log what the issue was, its urgency, changes made and any details to aid in sorting out any future ramifications of the changes. This data will help integrate changes into the codebase.
• Do a forensic inquiry. Discover what went wrong in the first place. Seek future remedies that do not involve quick software patches.

Handle hotfixes with care

Keep in mind that hotfixes are extreme measures. Don’t make these software patches common practice. To help boost your test coverage and avoid severe defects in the first place, consider a more comprehensive testing strategy that makes use of global crowdtesters who can mimic the real-world use of your product.

Contact Applause today to learn how some of the world’s leading brands rely on crowdtesting to deliver high-quality digital experiences.

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