What is Logging and Tracing?
Logging and tracing are crucial mechanisms for understanding and debugging software systems. They provide insights into system behavior by capturing events, messages, and execution paths.
Logging involves recording events and messages to a designated output, such as a file or a console. These records can be filtered, formatted, and analyzed to diagnose issues and identify patterns in system activity. [Source: https://en.wikipedia.org/wiki/Log_file]
Tracing focuses on tracking the flow of requests through a distributed system. It captures the sequence of operations, including timestamps, and provides a complete view of how a request is processed. This enables developers to identify bottlenecks, performance issues, and error propagation paths. [Source: https://en.wikipedia.org/wiki/Distributed_tracing]
Why is Logging and Tracing Important?
Logging and tracing play a vital role in various aspects of software development and operation:
- Debugging and Issue Resolution: Logs provide a detailed record of events and errors, aiding in troubleshooting and diagnosing issues. [Source: https://en.wikipedia.org/wiki/Debugging]
- Performance Monitoring: Tracing helps pinpoint performance bottlenecks by analyzing request durations and resource utilization across different system components. [Source: https://en.wikipedia.org/wiki/Performance_monitoring]
- Code Understanding: Tracing facilitates understanding the flow of execution through a codebase, revealing how requests are handled and data is processed. [Source: https://en.wikipedia.org/wiki/Code_tracing]
- Security Auditing: Logs can be used to record security-related events, such as access attempts and changes to system configurations, for auditing purposes. [Source: https://en.wikipedia.org/wiki/Security_auditing]
Logging
Zoekt utilizes the standard Go logging library (https://pkg.go.dev/log) for logging events and messages. The logging level can be configured via environment variables or command-line flags.
Tracing
Zoekt uses the OpenTelemetry library (https://opentelemetry.io/) to implement tracing capabilities. This allows for integration with various tracing systems like Jaeger and Zipkin.
Usage
Logging and tracing are used extensively within Zoekt to provide visibility into system operations. Examples include:
- Search Request Processing: Logs record details about each search request, including the query, time taken, and results.
- Index Creation and Management: Logs track the process of creating, updating, and deleting indexes.
- Error Handling: Logs capture error conditions and exceptions encountered during execution.
Tracing is leveraged to monitor the flow of requests through the search pipeline, providing insights into performance bottlenecks and potential issues.
Top-Level Directory Explanations
doc/ - This directory contains documentation for the project.
internal/ - This directory contains internal packages used by the project.
trace/ - This directory contains the code for tracing.
