Hello everyone, I am Xiaomi, a programmer who is keen on sharing technology. Today I want to talk to you about a topic that is often overlooked but extremely important when writing code-why you should write meaningful logs.
In daily programming work, we often hear the word "log", but some people may not understand why it is necessary to write logs in the code, or think that it is just an unnecessary cumbersome thing. But when you deeply understand the importance of logs and learn how to use them effectively, you'll find that they are an indispensable tool that can help you better understand, maintain, and improve your code.
What is a log?
First, let's understand what a log is. In programming, logging is a way of recording information while the system is running. This information can include the program's status, error messages, warnings, debugging information, and more. Logs are usually logged to a file, but can also be sent to other destinations, such as the console or a remote server.
The main purpose of logs is to provide visual feedback on what is happening while your code is running. They help developers track issues, analyze performance, monitor systems, and understand user behavior. In addition to these basic functions, logs also have some other important functions, let us take a look one by one.
Debugging and troubleshooting
When bugs occur in the code, logging is one of the most powerful tools. By viewing the logs, you can understand the various steps and status of the program during execution, helping you quickly locate and fix problems. Without logs, you could be fumbling in the dark and spending a lot of time diagnosing the problem.
For example, let's say users of your website report that a page is loading very slowly. By looking at the logs, you can discover which parts of your code are taking too long to execute, making it easier to find the root cause of performance issues.
Monitoring and performance analysis
Logs can also be used to monitor application health and performance. You can log key metrics such as response time, memory usage, number of database queries, etc. By analyzing this log data, you can identify potential performance issues in a timely manner and take steps to improve application performance.
Understand user behavior
Logging is also very useful if your application needs to collect user data. You can record user behavior, preferences, and actions to better understand their needs, improve user experience, and make targeted improvements.
safety
Security is a crucial aspect, especially for those applications that handle sensitive data. By logging security incidents and potential risks, you can better protect your applications and user data.
How to write meaningful diaries
Now that we know why we should log, let’s talk about how to write meaningful logs. Logging is more than just outputting some text to a file or console, it requires some skills and strategies.
1. Choose the appropriate log level
When writing logs, there are usually different log levels to choose from, including debug, information, warning, and error. You need to choose the appropriate level based on the importance and urgency of the information. Don't write so many low-level logs that you drown out critical information.
- Debug log: used to record detailed debugging information, only used during the development and testing phases.
- Information log: used to record important events and status information when the program is running normally.
- Warning log: Used to record potential problems or unusual situations that will not cause the program to crash.
- Error log: Used to record serious errors that may cause the program to crash or function to be unavailable.
2. Provide useful information
Each log message should provide enough information to understand the background and context of the problem if needed. This includes the timestamp of the recorded event, the module or function in which the event occurred, related parameters and data, etc.
3. Consider log format
Log format is very important for the readability and analyzeability of logs. You can choose a standard log format such as JSON, XML, or plain text for subsequent analysis and processing. Also, consider using a suitable logging library or tool to format and output logs.
4. Avoid leaking sensitive information
When writing logs, be careful not to accidentally reveal sensitive information such as passwords, API keys, or personal data. Make sure to close or obfuscate any logs that may contain sensitive information in your production environment.
Example: Why is journaling important?
Let’s use a simple example to illustrate why writing meaningful logs is important for maintaining and troubleshooting your code.
Suppose you are developing an e-commerce website that has a shopping cart functionality. Users can add items to their shopping cart and proceed to checkout. One day, you receive a complaint from a user saying that after adding items to their shopping cart, they are unable to complete their purchase.
If you don't have proper logging in your code, you will have to add temporary output statements to your code to debug the problem. Not only does this lead to cluttered code, it can also make your code difficult to maintain.
Instead, if you add logging to key parts of your shopping cart functionality, you can easily track user actions and understand where the problem lies. You can log the following information:
- User ID
- The user adds items to the shopping cart
- Number of items in shopping cart
- checkout operations
By looking at the logs, you may find that an exception occurred during checkout, or that the quantity of an item in your shopping cart is incorrect. This information will help you quickly locate the problem and fix it without having to modify a lot of code.
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Writing meaningful logs is critical for code maintenance, troubleshooting, and performance analysis. They can help you find and solve problems quickly, improve code maintainability and readability, and improve user experience. So, in your next project, don’t forget to add meaningful logs to your code, they will become your right-hand man.
I hope this article has inspired you. If you have any questions or experience sharing about logging, please leave a message in the comments and let us discuss it together. At the same time, if you like this article, please like, share and follow for more exciting content about technology. Thank you everyone for reading!
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