Observability #

In our web application development, observability is crucial for gaining insights into system behavior. It involves using various tools to surface application data through logs, metrics, and traces, which are the three pillars of observability. By collecting and analyzing data from these sources, we can understand our systems better and optimize performance.

We use New Relic for comprehensive performance monitoring and Sentry for error tracking and detailed logging, creating a robust observability framework for our projects.

Logging #

Logs are time-stamped records of discrete events within a system, providing valuable information for debugging and understanding system behavior including error messages, system status updates, transaction records, and operational events. Logging in web applications refers to keeping a log of all the operational events such as content creation, deletion, cron runs, and error reporting. These log messages can be recorded and kept in a log file (text format), in the database, or sent to an external service.

Effective Logging #

Effective logging involves understanding:

What data should be logged?
When to log?
Where to log?
How long to preserve logged data?

Automated tools like log analyzers and dashboards enhance visibility and reduce manual effort.

Logs can be categorized into:

Application-level logging: Logging events, messages, and data within the application.
Server-level logging: Logging server-related events. Logged messages typically include:
Date of the message
User
Severity
Type
The actual message, including a complete backtrace of the action performed

For details on logging and Sentry setup refer to our reference baseline.

Metrics #

Metrics are numerical representations of data measured over time, providing a high-level overview of the system’s health. They help track application and infrastructure health, alerting us to deviations from the norm.

Traces #

Traces provide a detailed view of function calls and requests during a single transaction, helping understand the program flow and identify performance bottlenecks.

APM (Application Performance Monitoring) #

APM involves monitoring and tracking software application performance using tools like New Relic, Elastic APM, and Sentry.

APM tools can monitor:

Uptime: Tracking application uptime and alerting if the application is down.
CPU usage: Monitoring CPU usage affected by query processing and other operations.
Transaction Monitoring: Monitoring processes like search functionality, user registration, content editing.
Page load speed: Recording and tracking page load speed.
Real-time user monitoring: Tracking active users and their operations on the website.

New Relic #

New Relic is a SaaS-based APM tool that uses Apdex scores to rate application performance. Key features include:

End-to-end user monitoring
External services performance monitoring
Synthetic monitoring
Key business transaction monitoring
Alerts and notifications
Availability and error monitoring
Native integration with third-party tools like Slack and PagerDuty

Sentry #

Sentry is an open-source APM and error tracking tool supporting over 30 coding languages with an SDK for integration.

For details on creating a project on Sentry and the details to set up the integration with other tools, refer to our reference baseline.

Elastic APM #

Elastic monitors software services and applications in real-time, collecting detailed performance information on response times, database queries, cache calls, external HTTP requests, and more.