spring-cloud-sleuth-annotation

Introduction

This extension to spring-cloud-sleuth gives you the ability to create "local" spans at points not instrumented by spring-cloud-sleuth by default. For example you could want to create local spans for database calls. With this extension you can create a new Span simply by adding an annotation to your method.

Example

The following method would be wrapped by a local span with name "TestClass/findProducts"

public class TestClass {
...
  @CreateSleuthSpan
  public List<Products> findProducts(Long tenantId, Integer minAmount) {
  ...
  }
}

Enable it

To use this library, you have to add the following two annotations to one of your configuration files:

@EnableAspectJAutoProxy
@Import(SleuthAnnotationConfiguration.class)

Further features

Customize span names

You can customize the name of the created span by adding the "name" attribute to @CreateSleuthSpan annotation. Example: The following will change the span name to "psql/findProductsByTenantAndAmount".

public class TestClass {
...
  @CreateSleuthSpan(name = "psql/findProductsByTenantAndAmount")
  public List<Products> findProducts(Long tenantId, Integer minAmount) {
  ...
  }
}

Add tags to span

There are 3 different ways to add tags to a span. All of them are controlled by the SleuthSpanTag annotation. Precedence is Way 3 -> Way 2 -> Way 1

Way 1: using toString method

The following method adds a tag with name "tenantId" and value of "tenantId.toString()" to the span:

public class TestClass {
...
  @CreateSleuthSpan(name = "psql/findProductsByTenantAndAmount")
  public List<Products> findProducts(@SleuthSpanTag("tenantId") Long tenantId, Integer minAmount) {
  ...
  }
}

Way 2: using SpEL expression for value

The following method adds a tag with name "tenantId" and value of "tenantId + 1" to the span:

public class TestClass {
...
  @CreateSleuthSpan(name = "psql/findProductsByTenantAndAmount")
  public List<Products> findProducts(@SleuthSpanTag(value = "tenantId", tagValueExpression = "param + 1") Long tenantId, Integer minAmount) {
  ...
  }
}

Way 3: use custom SleuthTagValueResolver Bean

The value of the tag for following method will be computed by an implementation of SleuthTagValueResolver interface.

public class TestClass {
...
  @CreateSleuthSpan(name = "psql/findProductsByTenantAndAmount")
  public List<Products> findProducts(@SleuthSpanTag(value = "tenantId", tagValueResolverBeanName = "tenantIdTagValueResolver") Long tenantId, Integer minAmount) {
  ...
  }
}