Overcoming an Unidentified Bug in our SpringBoot Application: My Inspiring Journey with the HNG Internship

Embarking on a journey with the HNG Internship program has been my career aspiration ever since I stumbled upon the program which I believe represents a significant step towards honing my backend development skills. You can be a part of this awesome opportunity by registering through this link https://hng.tech/internship . Recently, I encountered a particularly challenging problem that tested my abilities and pushed me to really think outside the box.

The Challenge

One of the most critical issues I faced involved an unidentified bug in our Spring Boot application that caused intermittent failures in the user registration process. The bug was elusive, not appearing consistently and leaving little trace in the logs, making it difficult to diagnose and resolve.

Step-by-Step Approach to Overcoming this Challenge

1. Understanding the Problem

This was the first step I adopted in handling this challenge. I tried to thoroughly understand the causes of this issue and gather as much information as possible about the failures. I utilized;

• User Reports: I collected detailed reports from users experiencing the issue, noting the specific circumstances under which the failures occurred.
• Log Analysis: I analyzed the logs for any patterns or anomalies that could provide clues, although the logs were sparse and inconsistent.
• Reproducing the Issue: I attempted to reproduce the issue in a controlled environment, running multiple tests under various conditions to trigger the bug.

1. *Identifying Potential Causes * With the initial information gathered, I brainstormed potential causes for the intermittent failures which I presumed maybe due to;

• Concurrency Issues: Given the sporadic nature of the bug, I considered concurrency issues, such as race conditions or thread safety problems.
• Database Transactions: I reviewed the database transactions to ensure that there were no issues with data consistency or integrity.
• Third-Party Services: I examined interactions with third-party services, considering whether external dependencies could be the cause of the intermittent failures.

1. *Enhanced Logging and Monitoring * To gather more data and pinpoint the issue, I implemented enhanced logging and monitoring using;

• Detailed Logging: I added detailed logging at various points in the registration process to capture more granular information about the application's state and behavior.
• Monitoring Tools: I set up monitoring tools like Prometheus and Grafana to track real-time metrics and visualize any patterns that emerged.

1. Code Review and Debugging

With enhanced logging in place, I conducted a thorough code review and debugging session.

• Code Review: I meticulously reviewed the code, looking for potential bugs, such as improper exception handling, uninitialized variables, or misconfigured dependencies.
• Debugging: Using a combination of IntelliJ IDEA's debugger and the new log data, I traced the execution flow to identify where the failures occurred.

1. Fixing the Bug

After a detailed analysis, I discovered that the issue stemmed from a misconfiguration in the Spring Boot application's dependency injection.

• Dependency Injection: The bug was caused by a race condition in the way certain beans were initialized. Specifically, a singleton bean was being accessed by multiple threads before it was fully initialized.
• Solution: I modified the bean scope and initialization logic to ensure proper synchronization. This involved using @PostConstruct to complete any necessary setup before the bean was accessed by other components. Below is a snippet of the correction I made in my code base;

@Service
public class UserService {

    private final UserRepository userRepository;
    private final SomeDependency someDependency;

    @Autowired
    public UserService(UserRepository userRepository, SomeDependency someDependency) {
        this.userRepository = userRepository;
        this.someDependency = someDependency;
    }

    @PostConstruct
    public void init() {
        // Ensure that someDependency is fully initialized before use
        someDependency.initialize();
    }

    // Registration logic
}

1. *Testing and Verification * With the fix implemented, rigorous testing was essential to ensure the bug was resolved.

• Unit Tests: I created detailed unit tests to cover all edge cases and ensure the registration process was robust.
• Integration Tests: I performed integration tests to verify that the entire process worked correctly in a real-world scenario.
• User Testing: I deployed the fix to a staging environment and invited users to test the registration process, monitoring for any further issues.

1. Deployment and Monitoring

Deployment to our production environment required careful planning to minimize disruptions. I also set up monitoring to track the performance and stability of the registration process in real-time.

• Deployment Planning: I planned the deployment to occur during off-peak hours, ensuring minimal impact on users.
• Monitoring Setup: I configured monitoring tools to track registration success rates, error rates, and other relevant metrics, allowing for proactive issue detection and resolution. and thank me later. Reflections on Overcoming this Challenge

Going through this backend challenge was undoubtedly demanding, but immensely rewarding. It not only deepened my technical expertise but also strengthened my problem-solving abilities and collaborative skills within a team setting. The experience reinforced my passion for backend development and my eagerness to continue learning and growing in this dynamic field.

My journey and I

I am that “tech-lady” that can almost never be caught without her eyes fixated on the screen. Yeah, that’s how much I enjoy coding and researching. Participating in this HNG Internship program is one of the goals I have smashed for this year and counting. _So proud of myself..lol. _

Why the HNG Internship

Being a part of the participants for the HNG Internship represents a pivotal opportunity to further expand my knowledge and skills under the mentorship of industry experts. The program’s focus on practical, hands-on experience aligns perfectly with my career goals of becoming a proficient backend developer. Moreover, the chance to work on real-world projects alongside talented peers promises to be a transformative learning experience.

In conclusion, resolving complex backend challenges is not just about writing code; it’s about understanding the problem deeply, designing elegant solutions, and continuously iterating towards improvement. The journey with the HNG Internship marks a new chapter in my career, filled with excitement, growth, and the promise of contributing meaningfully to the tech community. If you are looking to hire talented developers like myself, you can check out https://hng.tech/hire and thank me later.