diff --git a/spring-cloud-sleuth.html b/spring-cloud-sleuth.html index df2e1156e..24b9c0c9d 100644 --- a/spring-cloud-sleuth.html +++ b/spring-cloud-sleuth.html @@ -438,6 +438,11 @@ body.book #toc,body.book #preamble,body.book h1.sect0,body.book .sect1>h2{page-b
  • JSON Logback with Logstash
    • +
  • Propagating Span Context + +
  • Adding to the project @@ -935,6 +940,67 @@ If you’re using a custom logback-spring.xml then you have to +
    +

    Propagating Span Context

    +
    +

    The span context is the state that must get propagated to any child Spans across process boundaries. +Part of the Span Context is the Baggage. The trace and span IDs are a required part of the span context. +Baggage is an optional part.

    +
    +
    +

    Baggage is a set of key:value pairs stored in the span context. Baggage travels together with the trace +and is attached to every span. Spring Cloud Sleuth will understand that a header is baggage related if the HTTP + header is prefixed with baggage- and for messaging it starts with baggage_.

    +
    +
    + + + + + +
    +
    Important
    +    		 +There’s currently no limitation of the count or size of baggage items. However, keep in mind that +too many can decrease system throughput or increase RPC latency. In extreme cases, it could crash the app due +to exceeding transport-level message or header capacity. +
    +
    +
    +

    Example of setting baggage on a span:

    +
    +
    +
    +
    Span initialSpan = this.tracer.createSpan("span");
+initialSpan.setBaggageItem("foo", "bar");
    +
    +
    +
    +
    Baggage vs. Span Tags
    +
    +

    Baggage travels with the trace (i.e. every child span contains the baggage of its parent). Zipkin has no knowledge of +baggage and will not even receive that information.

    +
    +
    +

    Tags are attached to a specific span - they are presented for that particular span only. However you +can search by tag to find the trace, where there exists a span having the searched tag value.

    +
    +
    +

    If you want to be able to lookup a span based on baggage, you should add corresponding entry as a tag in the root span.

    +
    +
    +
    +
    @Autowired Tracer tracer;
+
+Span span = tracer.getCurrentSpan();
+String baggageKey = "key";
+String baggageValue = "foo";
+span.setBaggageItem(baggageKey, baggageValue);
+tracer.addTag(baggageKey, baggageValue);
    +
    +
    +
    +

    Adding to the project

    @@ -952,7 +1018,7 @@ the spring-cloud-starter-sleuth module to your project.

    <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> - <version>Brixton.RELEASE</version> + <version>Camden.RELEASE</version> <type>pom</type> <scope>import</scope> </dependency> @@ -981,7 +1047,7 @@ the Spring BOM

    dependencyManagement { (1)
     imports {
-        mavenBom "org.springframework.cloud:spring-cloud-dependencies:Brixton.RELEASE"
+        mavenBom "org.springframework.cloud:spring-cloud-dependencies:Camden.RELEASE"
     }
 }
 
@@ -1015,7 +1081,7 @@ the Spring BOM
    
              <dependency>
                  <groupId>org.springframework.cloud</groupId>
                  <artifactId>spring-cloud-dependencies</artifactId>
-                 <version>Brixton.RELEASE</version>
+                 <version>Camden.RELEASE</version>
                  <type>pom</type>
                  <scope>import</scope>
              </dependency>
@@ -1044,7 +1110,7 @@ the Spring BOM
    
 
    
 
    dependencyManagement { (1)
     imports {
-        mavenBom "org.springframework.cloud:spring-cloud-dependencies:Brixton.RELEASE"
+        mavenBom "org.springframework.cloud:spring-cloud-dependencies:Camden.RELEASE"
     }
 }
 
@@ -1078,7 +1144,7 @@ the Spring BOM
    
              <dependency>
                  <groupId>org.springframework.cloud</groupId>
                  <artifactId>spring-cloud-dependencies</artifactId>
-                 <version>Brixton.RELEASE</version>
+                 <version>Camden.RELEASE</version>
                  <type>pom</type>
                  <scope>import</scope>
              </dependency>
@@ -1122,7 +1188,7 @@ the Spring BOM
    
 
    
 
    dependencyManagement { (1)
     imports {
-        mavenBom "org.springframework.cloud:spring-cloud-dependencies:Brixton.RELEASE"
+        mavenBom "org.springframework.cloud:spring-cloud-dependencies:Camden.RELEASE"
     }
 }
 
@@ -1166,7 +1232,7 @@ dependency
    
              <dependency>
                  <groupId>org.springframework.cloud</groupId>
                  <artifactId>spring-cloud-dependencies</artifactId>
-                 <version>Brixton.RELEASE</version>
+                 <version>Camden.RELEASE</version>
                  <type>pom</type>
                  <scope>import</scope>
              </dependency>
@@ -1210,7 +1276,7 @@ the Spring BOM
    
 
    
 
    dependencyManagement { (1)
     imports {
-        mavenBom "org.springframework.cloud:spring-cloud-dependencies:Brixton.RELEASE"
+        mavenBom "org.springframework.cloud:spring-cloud-dependencies:Camden.RELEASE"
     }
 }