What is Debugging?
Debugging is the process of finding and fixing errors or bugs in the source code of any software. When software does not work as expected, computer programmers study the code to determine why any errors occurred. They use debugging tools to run the software in a controlled environment, check the code step by step, and analyze and fix the issue.
Where did the term debugging originate?
The term debugging can be traced back to Admiral Grace Hopper, who worked at Harvard University in the 1940s. When one of her colleagues found a moth impeding the operation of one of the university's computers, she told them they were debugging the system. Computer programmers were first recorded as using the terms bugs and debugging by the 1950s, and by the early 1960s, the term debugging was commonly accepted in the programming community.
Why is debugging important?
Bugs and errors happen in computer programming because it is an abstract and conceptual activity. Computers manipulate data in the form of electronic signals. Programming languages abstract this information so humans can interact with computers more efficiently. Any type of software has several layers of abstraction, with different components communicating for an application to work correctly. When errors occur, finding and resolving the issue can be challenging. Debugging tools and strategies help to fix problems faster and improve developer productivity. As a result, both software quality and the end-user experience improve.
How does the debugging process work?
The debugging process typically requires the following steps.
Developers, testers, and end-users report bugs they discover while testing or using the software. Developers locate the exact line of codes or code module causing the bug. This can be a tedious and time-consuming process.
Coders analyze the error by recording all program state changes and data values. They also prioritize the bug fix based on its impact on software functionality. The software team also identifies a timeline for bug fixing depending on development goals and requirements.
Fix and validation
Developers fix the bug and run tests to ensure the software continues to work as expected. They may write new tests to check if the bug recurs in the future.
Debugging vs. testing
Debugging and testing are complementary processes that ensure software programs run as they should. After writing a complete section or part of a code, programmers test to identify bugs and errors. Once bugs are found, coders can begin the process of debugging and work towards ridding software of any errors.
What are the coding errors that require debugging?
Software defects arise due to the complexity that is inherent to software development. Minor production errors are also observed after the software is live because customers use it in unexpected ways. We give below some common types of errors that often require the process of debugging.
A syntax error is a bug that occurs when a computer program has an incorrectly typed statement. It is the equivalent of a typo or spelling error in word processing. The program will not compile or run if syntax errors are present. The code editing software typically highlights this error.
Semantic errors occur due to the improper use of programming statements. For example, if you are translating the expression x/(2 π) into Python, you might write:
y = x / 2 * math.pi
However, this statement is not correct because multiplication and division have the same precedence in Python and are evaluated from left to right. Therefore, this expression computes as (xπ)/2, leading to bugs.
Logic errors occur when programmers misrepresent the step-wise process or algorithm of a computer program. For example, the code may exit a loop too early or may have an incorrect if-then outcome. You can identify logic errors by stepping through the code for several different input/output scenarios.
Runtime errors occur due to the computing environment in which the software code runs. Examples include insufficient memory space or stack overflow. You can resolve runtime errors by surrounding statements in try-catch blocks or logging the exception with an appropriate message.
What are some common debugging strategies?
There are several strategies programmers use to minimize errors and reduce the time required for debugging.
Incremental program development
Incremental development is developing programs in manageable sections so that small portions of the code are frequently tested. By doing this, programmers can localize any bugs that they find. It also allows them to work on one bug at a time rather than multiple errors after writing large sections of code.
Backtracking is a popular method of debugging, particularly for smaller programs. Developers work backwards from where a fatal error occurred to identify the exact point of occurrence in the code. Unfortunately, the process becomes more challenging to achieve as the number of lines of code increases.
Remote debugging is the debugging of an application running in a separate environment from your local machine. For example, you may use debugging tools installed remotely to solve the bug.
Most computer programs record internal data and other critical information like run time and operating system states in log files. Developers study log files to locate and resolve bugs. They also use tools like log analyzers to automate the processing of log files.
Debugging complex cloud applications is challenging because developers have to emulate cloud architectures on local machines. Overtime configuration differences can arise between the cloud environment and the emulated environment. This results in more bugs in production and longer development cycles. Special tools are required for more efficient cloud debugging.
How does AWS help with debugging?
AWS supports coding and debugging efforts in several different ways.
Plugins for popular IDEs
Developers use an Integrated Development Environment (IDE) to write code. AWS has several plugins compatible with IDEs and supports your debugging process. For example, AWS Toolkit for Eclipse is an open-source plugin for the Eclipse Java IDE that makes it easier for developers to develop, debug, and deploy Java applications using Amazon Web Services. Similarly, AWS also provides debugging support for other languages through plugins that integrate with other popular IDEs, such as:
These plugins support cloud debugging so that developers can debug cloud applications by directly accessing code running in the cloud.
AWS X-Ray is a debugging tool that developers use to analyze applications in development and production. It covers everything from simple three-tier applications to complex microservices applications consisting of thousands of services.
With X-Ray, you can:
- Understand how your application and its underlying services are performing
- Identify and troubleshoot the root cause of performance issues and errors
- Analyze an end-to-end view of requests as they travel through your application
Get started with AWS X-Ray by creating a free AWS account today.