API Tracing

What's an AWS X-Ray?

As the name suggests, Amazon X-Ray helps us see through the complete stack and look for what we need to know. One problem with microservice and serverless architecture is that the logs are scattered. As a result, tracking how different services process a particular request is challenging. AWS X-Ray makes this possible. It helps us trace a single request as it passes through different services and components of the system.

Why tracing?

Such functionality made little sense in the monolith world, where every request passed through a chain of function calls. It was easy to discover the entire request route sequentially laid out in the single log file. Microservice developers don’t have this luxury. This problem is worsened when we go serverless, where each request is processed by an independent Lambda function that spins up and dies out with the request. Half the processing in serverless applications is done without code in the other services like SQS, SNS, API Gateway, EventBridge, and so on.

In the production system, if we discover that a particular request wasn’t processed correctly, it’s difficult to identify the root cause because it’s difficult to identify logs related to that particular request. AWS X-Ray comes to our rescue when we’re stuck with such issues.

X-Ray requires minimal configuration and is smart enough to discover our application without much setup. It can trace through the path taken by every API request and comes up with a wonderful visualization of how that request was processed at each service.

Such visualization solves half the problem when debugging a complex serverless application.

Enable X-Ray

Let’s now see the X-Ray in action by implementing an API with traces enabled.