Application Programming Interfaces (APIs) are the foundation of modern inter-application communication. Their performance and availability directly impact end-user experience. Like other components of the application infrastructure, they must be monitored for availability, speed, error, and consistency.

This article covers the top best practices for effective API monitoring.

Best Practices for Effective API Monitoring

There are several key best practices for effective API monitoring that provide significant benefits:

1. Set Appropriate Key Performance Indicators

Clearly defining Key Performance Indicators (KPIs) or Service Level Objectives provides a benchmark to measure and understand API performance. Some common API performance metrics used as KPIs include:

Latency - the time to process a request
Response Time - the time to respond to a user request
Error Rate - the percentage of requests resulting in errors
Consistency/Accuracy - the predictability of system behavior
Availability - the uptime without disruptions
Throughput - the number of requests processed in a time frame

KPIs can also be customized to fit specific business needs. Once defined, KPIs enable creating Service Level Objectives (SLOs) which are performance targets for aspects of a system. SLOs facilitate Service Level Agreements (SLAs) between systems, especially with third-party vendors. SLAs can define compensation when agreements are not met.

Visualization of how a metric (KPI) can be used in conjunction with SLOs and SLAs

2. Continuous Real-Time Monitoring

APIs should be monitored 24/7 in real-time to detect anomalies and errors swiftly. Real-time monitoring enables a shorter mean time to recovery and reduces impact. Detecting issues early allows them to be addressed before evolving into larger problems affecting user experience, system performance, or data continuity.
Real-time monitoring is enabled by:

Services emitting logs and metrics while processing requests
Distributed tracing to track requests end-to-end
Emitting metrics and logs for 100% of traffic rather than samples

Endpoint level monitoring provides clearer understanding of bottlenecks or other issues. Solutions like Catchpoint gather metrics directly from user devices, tracing their internet journey for greater insight.

3. Set Up Alerts and Reporting

Alerts ensure teams are notified of problems needing attention. Metric and log-based alerts can trigger when values exceed thresholds. Alert configuration should balance avoiding noise fatigue and timely notifications. Reports help identify improvement opportunities and prove optimization successes.

Alert threshold chart

4. Integrate Monitoring with CI/CD Pipelines

Incorporating monitoring into continuous integration/continuous delivery (CI/CD) pipelines shifts monitoring left in the development process and bakes it in from the start. Pipelines can automatically generate and update dashboards so new metrics are covered when code reaches production.
Key aspects of pipeline integration include:

Validating data and SLOs by running pipeline tests against API endpoints using synthetic traffic to collect performance data
Identifying changes introduced across iterations
Enabling quick rollbacks when issues emerge

5. Understand the User Perspective

Monitoring user experience is critical for customer satisfaction, business performance, and product/service success. Synthetic monitoring emulates user transactions to measure workflow performance and detect issues proactively before users are impacted.
User perspective monitoring approaches include:

Simulating user requests from different regions and user types
Synthetic monitoring using scripts and real browsers to validate availability, performance, and functionality from an end user point of view
Promoting collaboration between technical and business teams to align monitoring priorities

As API endpoints serve end users, improving user experience based on monitoring data is key for positive outcomes. Frequently testing response data also builds perception of reliability and accuracy.

Conclusion

Effective API monitoring requires:

Customized KPIs tailored to business needs
Real-time monitoring to swiftly address issues
Actionable alerts balanced to notification needs
Integration with CI/CD pipelines for rapid iteration
Insights into user experience to guide improvements

By emphasizing these best practices, organizations can optimize API performance, and deliver a seamless and reliable user experience.

API Monitoring Best Practices