REST API Monitoring with PRTG

API

API stands for “application programming interface.” It is an interface that can be used to access the information of a program, operating system, or framework, and then exchange this information in a standardized manner. Communication takes place via the defined interface.

REST

REST stands for “representational state transfer.” It is a programming paradigm that is mostly used online. REST is an alternative to SOAP (Simple Object Access Protocol). Its architecture is significantly more modern and generates lighter loads. Another advantage of REST: a large part of the infrastructure, including web servers, HTML-compatible clients, and XML parsers, is already available on the Internet.

REST and HTTP

To communicate with RESTful APIs, an HTTP or HTTPS request is sent to a target, for example a web address. This communication occurs by way of GET and POST. GET has read-access to resources. With POST, data can be sent along with the request.

RESTful API

Many web environments, websites, and web services use RESTful APIs. These programming interfaces are based on REST. HTTP requests placed via a REST or RESTful API return XML and JSON files, which can then be selected to monitor desired values, for example.

REST and RESTful

REST stands for the architectural style or programming paradigm. Web services or websites are “RESTful” when they use or implement REST.

REST API monitoring refers to the process of tracking and analyzing the performance, functionality, availability, and reliability of REST APIs (Representational State Transfer Application Programming Interfaces). It involves assessing the APIs to ensure they are working correctly, meeting performance expectations, and providing a seamless experience for users or applications that rely on them.

Use cases of REST API monitoring include:

• Performance monitoring: Measures metrics such as response time, latency, and throughput to ensure APIs meet the required speed and efficiency. Identifies bottlenecks and delays in API calls.
• Uptime monitoring: Tracks the uptime and downtime of APIs to ensure they are accessible when needed. Helps identify outages or instances where the API is unreachable.
• Error monitoring: Logs and tracks API errors, such as HTTP status codes (e.g., 4xx for client errors, 5xx for server errors).
• Functional monitoring: Verifies that API functionality is working as expected by testing endpoints and ensuring correct data is returned. May involve automated API testing or simulated requests.
• User monitoring: Tracks API usage patterns to understand traffic trends and monitor for unusual activity. Helps identify potential abuse or misconfiguration.
• Security monitoring: Ensures APIs are secure by checking for vulnerabilities like improper authentication, lack of encryption, or rate-limiting bypass. Monitors for malicious activities such as API abuse or injection attacks.

There are several benefits of REST API monitoring, including:

• Improved reliability: Proactively detects and resolves issues before they affect users.
• Enhanced performance: Optimizes API response times and reduces latency.
• Better user experience: Ensures that APIs deliver consistent and expected results to end users or dependent systems.
• Reduced downtime: Quickly identifies outages or failures for faster recovery.
• Compliance & security: Maintains data protection standards and SLAs, and identifies security vulnerabilities.

In PRTG, “sensors” are the basic monitoring elements. One sensor usually monitors one measured value in your network, for example the traffic of a switch port, the CPU load of a server, or the free space on a disk drive. On average, you need about 5-10 sensors per device or one sensor per switch port.