Chapter 356. Zipkin Component

Available as of Camel 2.18

The camel-zipkin component is used for tracing and timing incoming and outgoing Camel messages using zipkin.

Events (span) are captured for incoming and outgoing messages being sent to/from Camel.

Note

camel-zipkin is planned to be refactored in Camel 2.22.0 to not use zipkin-scribe but use the default http transport. This work may cause backwards incompatibility.

This means you need to configure which Camel endpoints map to zipkin service names.

The mapping can be configured using:

  • route id - A Camel route id
  • endpoint url - A Camel endpoint url

For both kinds you can match using wildcards and regular expressions, using the rules from Intercept.

To match all Camel messages you can use * in the pattern and configure that to the same service name.

If no mapping has been configured, Camel will fallback and use endpoint uri’s as service names. 
However, it’s recommended to configure service mappings so you can use human-readable names instead of Camel endpoint uris in the names.

Camel will auto-configure a span reporter one hasn’t been explicitly configured, and if the hostname and port to a zipkin collector has been configured as environment variables

  • ZIPKIN_COLLECTOR_HTTP_SERVICE_HOST - The http hostname
  • ZIPKIN_COLLECTOR_HTTP_SERVICE_PORT - The port number

or

  • ZIPKIN_COLLECTOR_THRIFT_SERVICE_HOST - The Scribe (Thrift RPC) hostname
  • ZIPKIN_COLLECTOR_THRIFT_SERVICE_PORT - The port number

This makes it easy to use camel-zipkin in container platforms where the platform can run your application in a linux container where service configurations are provided as environment variables.

356.1. Options

OptionDefaultDescription

rate

1.0f

Configures a rate that decides how many events should be traced by zipkin. The rate is expressed as a percentage (1.0f = 100%, 0.5f is 50%, 0.1f is 10%).

spanReporter

 

Mandatory: The reporter to use for sending zipkin span events to the zipkin server.

serviceName

 

To use a global service name that matches all Camel events

clientServiceMappings

 

Sets the client service mappings that matches Camel events to the given zipkin service name. The content is a Map<String, String> where the key is a pattern and the value is the service name. The pattern uses the rules from Intercept.

serverServiceMappings

 

Sets the server service mappings that matches Camel events to the given zipkin service name. The content is a Map<String, String> where the key is a pattern and the value is the service name. The pattern uses the rules from Intercept.

excludePatterns

 

Sets exclude pattern(s) that will disable tracing with zipkin for Camel messages that matches the pattern. The content is a Set<String> where the key is a pattern. The pattern uses the rules from Intercept.

includeMessageBody

false

Whether to include the Camel message body in the zipkin traces. This is not recommended for production usage, or when having big payloads. You can limit the size by configuring the max debug log size

includeMessageBodyStreams

false

Whether to include message bodies that are stream based in the zipkin traces. This requires enabling streamcaching on the routes or globally on the CamelContext. This is not recommended for production usage, or when having big payloads. You can limit the size by configuring the max debug log size.  

356.2. Example

To enable camel-zipkin you need to configure first

ZipkinTracer zipkin = new ZipkinTracer();
// Configure a reporter, which controls how often spans are sent
//   (the dependency is io.zipkin.reporter2:zipkin-sender-okhttp3)
sender = OkHttpSender.create("http://127.0.0.1:9411/api/v2/spans");
zipkin.setSpanReporter(AsyncReporter.create(sender));
// and then add zipkin to the CamelContext
zipkin.init(camelContext);

The configuration above will trace all incoming and outgoing messages in Camel routes. 

To use ZipkinTracer in XML, all you need to do is to define scribe and zipkin tracer beans. Camel will automatically discover and use them.

  <!-- configure how to reporter spans to a Zipkin collector
          (the dependency is io.zipkin.reporter2:zipkin-reporter-spring-beans) -->
  <bean id="http" class="zipkin2.reporter.beans.AsyncReporterFactoryBean">
    <property name="sender">
      <bean id="sender" class="zipkin2.reporter.beans.OkHttpSenderFactoryBean">
        <property name="endpoint" value="http://localhost:9411/api/v2/spans"/>
      </bean>
    </property>
    <!-- wait up to half a second for any in-flight spans on close -->
    <property name="closeTimeout" value="500"/>
  </bean>

  <!-- setup zipkin tracer -->
  <bean id="zipkinTracer" class="org.apache.camel.zipkin.ZipkinTracer">
    <property name="serviceName" value="dude"/>
    <property name="spanReporter" ref="http"/>
  </bean>

356.2.1. ServiceName

However, if you want to map Camel endpoints to human friendly logical names, you can add mappings

  • ServiceName *

You can configure a global service name that all events will fallback and use, such as:

zipkin.setServiceName("invoices");

This will use the same service name for all incoming and outgoing zipkin traces. If your application uses different services, you should map them to more finely grained client / server service mappings

356.2.2. Client and Server Service Mappings

  • ClientServiceMappings
  • ServerServiceMappings

If your application hosts a service that others can call, you can map the Camel route endpoint to a server service mapping. For example, suppose your Camel application has the following route:

from("activemq:queue:inbox")
  .to("http:someserver/somepath");

And you want to make that as a server service, you can add the following mapping:

zipkin.addServerServiceMapping("activemq:queue:inbox", "orders");

Then when a message is consumed from that inbox queue, it becomes a zipkin server event with the service name 'orders'.

Now suppose that the call to http:someserver/somepath is also a service, which you want to map to a client service name, which can be done as:

zipkin.addClientServiceMapping("http:someserver/somepath", "audit");

Then in the same Camel application you have mapped incoming and outgoing endpoints to different zipkin service names.

You can use wildcards in the service mapping. To match all outgoing calls to the same HTTP server you can do:

zipkin.addClientServiceMapping("http:someserver*", "audit");

356.3. Mapping rules

The service name mapping for server occurs using the following rules

  1. Is there an exclude pattern that matches the endpoint uri of the from endpoint? If yes then skip.
  2. Is there a match in the serviceServiceMapping that matches the endpoint uri of the from endpoint? If yes, then use the found service name
  3. Is there a match in the serviceServiceMapping that matches the route id of the current route? If yes, then use the found service name
  4. Is there a match in the serviceServiceMapping that matches the original route id where the exchange started? If yes, then use the found service name
  5. No service name was found, the exchange is not traced by zipkin

The service name mapping for client occurs using the following rules

  1. Is there an exclude pattern that matches the endpoint uri of the from endpoint? If yes then skip.
  2. Is there a match in the clientServiceMapping that matches the endpoint uri of endpoint where the message is being sent to? If yes, then use the found service name
  3. Is there a match in the clientServiceMapping that matches the route id of the current route? If yes, then use the found service name
  4. Is there a match in the clientServiceMapping that matches the original route id where the exchange started? If yes, then use the found service name
  5. No service name was found, the exchange is not traced by zipkin

356.3.1. No client or server mappings

If there has been no configuration of client or server service mappings, CamelZipkin runs in a fallback mode, and uses endpoint uris as the service name.

In the example above, this would mean the service names would be defined as if you add the following code yourself:

zipkin.addServerServiceMapping("activemq:queue:inbox", "activemq:queue:inbox");
zipkin.addClientServiceMapping("http:someserver/somepath", "http:someserver/somepath");

This is not a recommended approach, but gets you up and running quickly without doing any service name mappings. However, when you have multiple systems across your infrastructure, then you should consider using human-readable service names, that you map to instead of using the camel endpoint uris.

356.4. camel-zipin-starter

If you are using Spring Boot then you can add the camel-zipkin-starter dependency, and turn on zipkin by annotating the main class with @CamelZipkin. You can then configure camel-zipkin in the application.properties file where you can configure the hostname and port number for the Zipkin Server, and all the other options as listed in the options table above.

You can find an example of this in the https://github.com/apache/camel/tree/master/examples/camel-example-zipkin[camel-example-zipkin]