Using X-Ray Agent in Spring Boot & Zuul Proxy API Gateway

We are trying to instrument our microservices using x-ray java agent. Our microservices are implemented using Spring Boot framework. For other microservices, we accomplished the auto instrumentation using the disco plugins by adding environment variables to our applications as below.

> -Dcom.amazonaws.xray.strategy.tracingName=serviceName
> -Dcom.amazonaws.xray.strategy.contextMissingStrategy=IGNORE_ERROR
> -Dcom.amazonaws.xray.emitter.daemonAddress=127.0.0.1:2000
> -Dcom.amazonaws.xray.tracingEnabled=True
> -javaagent:src/main/resources/disco/disco-java-agent.jar=pluginPath=src/main/resources/disco/disco-plugins

But in our API Gateway, we failed to do so. While we try to trace any request from our API Gateway, we came across an error like this below:

> {
> "error": "Exception while serializing entity.",
> "stack_trace":"com.fasterxml.jackson.databind.JsonMappingException: Failed to load class
> 'com.amazonaws.xray.entities.SegmentImpl$Access4JacksonSerializerdb8acfce':
> com.fasterxml.jackson.module.afterburner.ser.BeanPropertyAccessor
> com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:295)
> }
> [full-stack-trace.json.zip](https://github.com/aws/aws-xray-java-agent/files/7633675/full-stack-trace.json.zip)
>

Also in our x-ray daemon running locally, we encountered with this warning below:

> [Warn] Missing header or segment: {"format": "json", "version": 1}

To resolve this error, we tried to exclude plugin path from command like below:

> -Dcom.amazonaws.xray.strategy.tracingName=bid-service-local
> -Dcom.amazonaws.xray.strategy.contextMissingStrategy=IGNORE_ERROR
> -Dcom.amazonaws.xray.emitter.daemonAddress=127.0.0.1:2000
> -Dcom.amazonaws.xray.tracingEnabled=True
> -javaagent:src/main/resources/disco/disco-java-agent.jar

But there was no segment sent to the daemon that is running locally. Then we tried to add the plugins to its path one by one,

> aws-xray-agent-plugin.jar
> disco-java-agent-aws-plugin.jar

First, we added the two jars above to disco-plugins path above, there was no error, but segment also not sent to our daemon .

Then, we added the jar below and, we saw that this error is related to this plugin, with some dependencies that we use in our API Gateway application.

> disco-java-agent-web-plugin.jar
>
> Dependencies & Technologies
>
> Spring Boot version is 2.3.8.
>
> ```
> - implementation "org.springframework.boot:spring-boot-configuration-processor"
> - implementation "org.springframework.boot:spring-boot-starter-actuator"
> - implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
> - implementation 'org.springframework.cloud:spring-cloud-starter-netflix-zuul'
> - implementation 'org.springframework.cloud:spring-cloud-starter-netflix-hystrix-dashboard'
> - implementation 'org.springframework.cloud:spring-cloud-starter-netflix-hystrix'
> - implementation 'org.springframework.cloud:spring-cloud-starter-netflix-ribbon'
> - implementation "org.springframework.cloud:spring-cloud-starter-sleuth:2.2.8.RELEASE"
> ```
>

Also we are using `ZuulFilter` to add custom headers to incoming requests' header. Could this also be an issue for our error that we encounter, how can we move forward from here? 🙏