Few tips using Zipkin

Zipkin is a very useful tracing solution while building microservice. (It is also useful at any service because it measure latency between two services). It becomes more and more popular but there are little documents. This post is few tips while adapting Zipkin in production.

Zipkin with Finatra

Zipkin is firstly made by Twitter and it supports Finatra (Base on Twitter Server and Finagle) well. Integrating Zipkin with Finatra is very simple.

1. Just add a dependency to project.(libraryDependencies in build.sbt)

com.twitter" %% "finagle-zipkin" %% finagle-version

2. And after that, just add Twitter flag while running Finatra Server. You can see Twitter flags when you add ‘-help’ end of jar or SBT. And all you need to know about flags related to Zipkin is

-thrift.name='thrift': Thrift server name // When Thrift Server
or
-http.name='http': Http server name // When Http Server
-com.twitter.finagle.zipkin.host='localhost:1463': Host to scribe traces to
-com.twitter.finagle.zipkin.initialSampleRate='0.001': Initial sample rate

Yes! when you add Twitter flags end of your application, it works! But sometimes, I have to check whether it is applied. Then you can check in Twitter Server admin. Its URL is ‘admin/clients/zipkin-tracer’.

If you set Zipkin Server properly, you can see your server address in ‘Set(Inet({Server Address}, Map()))’.

Add Twitter flag in SBT

When you want to add Twitter flags while in sbt run, you can add twitter flags like this

$ sbt 'run -help'

Existing instrumentations

Zipkin support many framework and language. If you want to find a supported framework, You can find it here.

Scribe

Above page, there are main 2 kinds of protocol, HTTP, and Scribe. As you know, Zipkin Server supports Http and Scribe. I was very curious what a Scribe is. You can see description in here. Simply to say, Scribe is logging protocol base on thrift.

com.twitter:finagle-zipkin

finagle-zipkin has two version. One is openzipkin/zipkin-finagle and another is finagle-zipkin in twitter/finagle. What is a difference between two things? openzipkin/zipkin-finagle is maintained by the openzipkin group. You can select protocol HTTP and Scribe. But, finagle-zipkin in twitter/finagle is little different. It supports only Scribe. so, if you want to connect with Finatra, you have to load Zipkin Server which supports Scribe.

Ports

Zipkin needs two port. One is 9411 which get HTTP Request. And 9410 which support Scribe. 9410 port is only opened when you enable Scribe support.