Magento 2 Logging and Debugging: Tools and Differences

• What is Magento 2 Logging?

• What is Magento 2 Debugging?

• Common Magento 2 Log Levels

• Debugging Common Magento 2 Issues

• Tools for Enhanced Logging and Debugging

• Difference Between Magento 2 Logging and Debugging

• FAQs

• Summary

What is Magento 2 Logging?

Magento 2 Logging is the process of recording system activities and events within a Magento 2 store.

The technique uses the Monolog library to track and store information in log files, such as:

• System.log

• Exception.log

• Debug.log

These logs help monitor system performance and debug errors effectively. Magento 2 supports various log levels, providing detailed insights into application behavior.

Developers can also create custom logs for specific modules or features. It helps maintain store stability and resolve technical issues efficiently.

What is Magento 2 Debugging?

“Magento 2 debugging is the process of identifying and resolving issues within a Magento 2 eCommerce store.”

The technique involves analyzing errors and using tools to diagnose problems such as:

• Code bugs

• Performance bottlenecks

• Extension conflicts

Key debugging methods include enabling Developer Mode and examining log files. It also involves using tools like Xdebug for PHP debugging or browser developer tools for front-end issues.

Debugging helps troubleshoot API errors and configuration mismatches. By systematically resolving these issues, Magento 2 debugging ensures optimal store performance and a smooth experience.

Common Magento 2 Log Levels

1. DEBUG

• DEBUG is the most detailed and low-level logging information.

• The log level provides in-depth insights into the system's internal state. It helps developers trace the execution flow. It also helps pinpoint the root cause of issues.

• It is used during the development phase. It is also used to debug specific scenarios in a staging environment.

Examples:

• Logs variable values or query execution times.

• "Entering method: Product::getPrice() with parameters: [productId=101]."

2. INFO

• INFO logs general information about normal operations.

• The level tracks successful system activities or events. It helps maintain a record of routine operations.

• It is used in both the development and production environments. It helps log significant but non-critical activities.

Examples:

• "Cron job executed successfully."

• "Cache cleared for store ID 1."

3. NOTICE

• NOTICE logs normal but noteworthy events that may require attention.

• The level highlights events that could indicate non-critical issues or areas for improvement. It helps identify deprecated functions or less-than-ideal code usage.

• It is used when monitoring system upgrades or code deprecations.

Examples:

• "Deprecated function getOldPrice() used in module."

• "Product price rounding might affect calculations."

4. WARNING

• WARNING indicates potential issues that may lead to problems if left unresolved.

• The level alerts about conditions that could degrade system performance or reliability. It enables early detection of minor issues before they escalate.

• It is used in production and development environments for preventive monitoring.

Examples:

• "Cache storage nearing capacity: 90% full."

• "Slow query detected: SELECT * FROM sales_order took 3.5 seconds."

5. ERROR

• ERROR logs runtime errors that affect specific functionalities but do not stop the entire system.

• The level highlights issues that require attention to restore affected features.

• It is commonly used to address module errors or API failures during production monitoring.

Examples:

• "Unable to load module configuration file: payment_methods.xml."

• "Payment gateway returned an invalid response."

6. CRITICAL

• CRITICAL logs severe issues that impact the core functionality of the system.

• The level helps prevent the application from performing key operations. It helps prioritize and resolve high-impact errors promptly.

• It is used for real-time monitoring in production to address urgent issues.

Examples:

• "Database connection failed."

• "Unable to load payment module: PayPal."

Debugging Common Magento 2 Issues

Common Issues	Symptoms	Debugging Steps	Common Fixes
1. PHP Errors	White screen or error messages in the browser. PHP fatal errors or warnings in the logs.	Edit php.ini to enable display_errors and error_reporting. Enable Developer Mode: php bin/magento deploy:mode:set developer. Inspect var/log/exception.log and var/log/system.log for specific PHP errors. Use Xdebug with an IDE to step through the code and identify the problematic function or variable.	Ensure PHP version compatibility with Magento 2. Resolve syntax errors, missing dependencies, or incorrect configurations.
2. Frontend Issues	Broken layouts, missing elements, or JavaScript errors. CSS changes are not reflected on the website.	Use the browser’s "Inspect Element" feature. You can check for JavaScript errors, CSS conflicts, or missing assets. Regenerate static files: php bin/magento setup:static-content:deploy. Clear the Magento cache: php bin/magento cache:flush. Check the browser console for JavaScript errors. Debug AJAX calls to ensure correct responses.	Verify theme and module compatibility. Ensure proper permissions for the pub/static directory.
3. Performance Issues	Slow page load times or high server load. Timeout errors during heavy traffic.	Activate the Magento profiler to track execution time for Magento operations. Review var/log/debug.log for database queries and execution times. Use database query logs to identify slow queries. Optimize indexes and clean unnecessary data. Ensure proper caching setup. Reindex data: php bin/magento indexer:reindex.	Optimize custom modules or third-party extensions that are causing bottlenecks. Use content delivery networks (CDNs) for static assets.
4. Extension Conflicts	Errors or unexpected behavior after installing new extensions. Features overlapping or modules not functioning properly.	Use tools like Magento Conflict Checker to identify overlapping class rewrites. Disable suspected modules one by one to isolate the issue: php bin/magento module:disable Vendor_Module. Review exception logs for module-related errors.	Resolve conflicts by merging customizations into one plugin. Contact the extension provider for support.
5. API and Integration Issues	Errors in API responses or failure to connect to third-party services.	Use tools like Postman to test Magento REST or SOAP API endpoints. Validate request and response payloads. Debug API-related logs in var/log/debug.log. Display detailed error messages for API issues.	Check API credentials and permissions. Update endpoints or configurations for compatibility.
6. Database Errors	Data not displaying correctly or corrupted entries. SQL errors in the application or logs.	Enable MySQL’s slow query log to identify problematic queries. Check for missing or corrupted tables. Reindex Data: Run php bin/magento indexer:reindex.	Repair or optimize database tables. Validate database credentials and configurations in app/etc/env.php.
7. Cache and Indexing Problems	Changes not reflected in the store. Errors during cache clearing or reindexing.	Flush and Rebuild Cache: Run php bin/magento cache:flush and cache:clean. Reindex Data: Run php bin/magento indexer:reindex. Ensure proper file and folder permissions for cache directories.	Use Redis or Varnish for powerful caching. Fix indexing errors by troubleshooting specific indexers.
8. Email Sending Issues	Emails are not being sent or received by customers.	Use a reliable SMTP extension for Magento 2. Review email-related logs for errors. Send test emails to verify settings.	Ensure proper mail server configuration. Use third-party email services like SendGrid or Mailgun.

Tools for Enhanced Logging and Debugging

A. Logging Tools

1. Mageplaza Log Viewer

• It is an extension used to view Magento 2 logs directly in the admin panel.

• The tool categorizes logs for easier navigation. It provides real-time log updates without server access.

• It simplifies log analysis, especially for non-technical administrators.

2. Monolog

• It is the built-in logging library in Magento 2.

• The tool supports multiple log levels, including DEBUG, INFO, and ERROR. It allows custom log handlers to do advanced logging.

• It customizes the logging framework for complex applications.

3. Graylog

• It is a centralized log management system.

• The tool aggregates and visualizes logs from multiple sources. It supports advanced filtering and searching.

• It monitors logs across Magento instances for large-scale operations.

4. New Relic

• It is an application performance monitoring tool.

• The tool tracks server and application performance metrics. It integrates with Magento for real-time error reporting.

• It helps monitor and troubleshoot performance in production environments.

5. Sentry

• It is a log aggregation and error-tracking platform.

• The tool captures exceptions and errors in real-time. It provides detailed stack traces for debugging.

• It centralizes error monitoring for Magento stores.

6. ELK Stack (Elasticsearch, Logstash, Kibana)

• It is a powerful suite for log:

  1. Aggregation

  2. Analysis

  3. Visualization

• The tool helps collect logs from multiple servers. It creates dashboards for performance and error trends.

• It is used for comprehensive log management for enterprise-scale Magento deployments.

B. Debugging Tools

1. MySQL Workbench

• It is a graphical tool for MySQL database management.

• The tool debugs and optimizes database queries. It visualizes database schema and relationships.

• It debugs slow queries or database-related errors in Magento.

2. phpMyAdmin

• It is a web-based database management tool.

• The tool allows direct manipulation of Magento’s database. It facilitates query execution and debugging.

• It helps identify and resolve database inconsistencies.

3. Postman

• It is an API testing and debugging tool.

• The tool helps send and test REST/SOAP API requests. It provides detailed request/response information.

• It debugs Magento 2 API integration issues.

4. SOAP UI

• It is a tool used to test SOAP APIs.

• The tool validates WSDL files and SOAP requests. It tracks API errors and inconsistencies.

• It troubleshoots SOAP-based integrations.

Difference Between Magento 2 Logging and Debugging

Aspect	Magento 2 Logging	Magento 2 Debugging
1. Purpose	Logging records system activities, errors, and events. It is used for monitoring and analysis.	Debugging diagnoses and resolves issues within the codebase, configuration, or system performance.
2. Focus	It enables long-term monitoring of system health and activities.	It enables short-term investigation to identify and fix specific issues.
3. Output	Logs are stored in files (system.log, exception.log) in the var/log/ directory.	Debugging outputs include error messages, stack traces, and variable values during runtime.
4. Usage	It helps track historical data for auditing and troubleshooting.	It is actively used during development or when resolving an immediate issue.
5. Tools	Built-in Monolog library Log viewers, including Mageplaza Log Viewer Centralized tools, including ELK and Sentry	Xdebug for PHP debugging Browser developer tools for frontend debugging Magento profiler for performance analysis.
6. Environment	It is used in both development and production environments.	It is primarily used in development or staging environments.
7. Scope	It captures events across the entire application. These include errors, warnings, and system activities.	It is focused on isolating and fixing specific issues within the code, database, or front end.
8. Log Levels	It supports multiple levels like DEBUG, INFO, WARNING, and ERROR. These are used for categorizing log entries.	There are no predefined levels. Debugging involves tracking code behavior and identifying the cause of issues.
9. Examples	Recording errors in third-party integrations Monitoring cron job execution Capturing deprecation warnings	Diagnosing PHP syntax errors Debugging API request failures Fixing layout or JavaScript issues
10. Proactive/Reactive	These are proactive. Logs can be reviewed regularly to prevent potential issues.	These are reactive. Debugging is triggered in response to a specific problem or error.

FAQs

1. How do I enable the Magento 2 debug log?

Set your store to developer mode using the command php bin/magento deploy:mode:set developer. Debug logs are stored in the var/log/ directory within your Magento root directory. It helps developers identify issues during Magento 2 development and troubleshooting.

2. What is the Magento error log, and how can it help?

The Magento error log records detailed error messages. It is located in the var/log/exception.log file. It helps developers and administrators troubleshoot problems such as server errors and API failures. Ensuring logs are properly configured improves the debugging process.

3. Where can I find cron logs in Magento 1 or Magento 2.3.1?

Cron logs track the execution of scheduled tasks. These are located in the var/log/system.log file. These logs help administrators monitor cron jobs for reindexing and cache cleaning. They ensure smooth operations for various processes.

4. What is the role of logging in Magento 2 production mode?

Logging in to Magento 2 ensures efficient monitoring of the Magento 2 system while optimizing performance. While debug mode is disabled, critical logs like syslog and exception.log help troubleshoot problems. They don’t impact live store performance.

Summary

Magento 2 logging and debugging helps maintain system performance and ensure a smooth store experience. The article explores the key points of the techniques, including:

• Magento 2 logging uses Monolog to track system events with log levels.

• Magento 2 debugging identifies and resolves issues using different tools.

• Common debugging issues include PHP errors and front-end problems.

• Logging and debugging tools enhance issue resolution and system optimization.

Optimize your eCommerce store with expert tools for logging and debugging. Pair it with managed Magento hosting for better performance and hassle-free issue resolution.