HttpClient Integration

In this document will demonstrate how to use SOFATracer to track of HttpClient, this example address.

Assuming you have built a simple Spring Web project based on SOFABoot, Then you can be operated by the following steps:

Introduce dependency

<!-- SOFATracer dependency -->
<dependency>
    <groupId>com.alipay.sofa</groupId>
    <artifactId>tracer-sofa-boot-starter</artifactId>
</dependency>
<!-- HttpClient dependency -->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <!--  4.5.X  -->
    <version>4.5.3</version>
</dependency>
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpasyncclient</artifactId>
    <!--  4.X -->
    <version>4.1.3</version>
</dependency>

Project Configuration

Then, add the parameters to be used by SOFATracer under the project’s application.properties file, including spring.application.name that indicates the current application name and logging.path that specifies the log output directory.

# Application Name
spring.application.name=HttpClientDemo
# logging path
logging.path=./logs

Add a Controller that provides RESTful service

@RestController
public class SampleRestController {

    private final AtomicLong counter = new AtomicLong(0);

    /**
     * Request http://localhost:8080/httpclient?name=
     * @param name name
     * @return Map of Result
     */
    @RequestMapping("/httpclient")
    public Map<String, Object> greeting(@RequestParam(value = "name", defaultValue = "httpclient") String name) {
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("count", counter.incrementAndGet());
        map.put("name", name);
        return map;
    }
}

Construct HttpClient to initiate a call to the RESTful service above

The code example is as follows:

• Construct an HttpClient synchronous call instance:

HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
// SOFATracer
SofaTracerHttpClientBuilder.clientBuilder(httpClientBuilder);
CloseableHttpClient httpClient = httpClientBuilder.setConnectionManager(connManager).disableAutomaticRetries()
                .build();

• Construct an HttpClient asynchronous call instance:

RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(6000).setConnectTimeout(6000).setConnectionRequestTimeout(6000).build();
HttpAsyncClientBuilder httpAsyncClientBuilder = HttpAsyncClientBuilder.create();
//tracer
SofaTracerHttpClientBuilder.asyncClientBuilder(httpAsyncClientBuilder);
CloseableHttpAsyncClient asyncHttpclient = httpAsyncClientBuilder.setDefaultRequestConfig(requestConfig).build();

When you construct the HttpClient via the SofaTracerHttpClientBuilder (clientBuilder method for synchronous call instance, and asyncClientBuilder method for asynchronous call instance) to initiate a call to the RESTful service above, the link data of SOFATracer can be tracked.

Run the project

Start Current SOFABoot Application. You will see the log about startup in the console:

2018-09-27 20:31:21.465  INFO 33277 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2018-09-27 20:31:21.599  INFO 33277 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2018-09-27 20:31:21.608  INFO 33277 --- [           main] c.a.s.t.e.h.HttpClientDemoApplication    : Started HttpClientDemoApplication in 5.949 seconds (JVM running for 6.573)

If there is a log similar to the followings, it indicates that the call to HttpClient succeeded:

2018-09-27 20:31:22.336  INFO 33277 --- [           main] c.a.s.t.e.h.HttpClientDemoApplication    : Response is {"count":1,"name":"httpclient"}
2018-09-27 20:31:22.453  INFO 33277 --- [           main] c.a.s.t.e.h.HttpClientDemoApplication    : Async Response is {"count":2,"name":"httpclient"}

View log

In the application.properties, the log printing directory we configured is ./logs, which is the root directory of the current application (we can configure it based on actual situation). Thus, in the root directory of the current project, you can see log files in the structure similar to the followings:

./logs
├── spring.log
└── tracelog
    ├── httpclient-digest.log
    ├── httpclient-stat.log
    ├── spring-mvc-digest.log
    ├── spring-mvc-stat.log
    ├── static-info.log
    └── tracer-self.log

In the example, a call to the same RESTful service is initiated by constructing two HttpClients (one is synchronous and the other is asynchronous). After the call is completed, you can see the log similar to the followings in httpclient-digest.log. About the meaning of each output field, you can see documentation for SOFATracer.

{"time":"2018-09-27 20:31:22.328","local.app":"HttpClientDemo","traceId":"0a0fe8801538051482054100133277","spanId":"0","request.url":"http://localhost:8080/httpclient","method":"GET","result.code":"200","req.size.bytes":0,"resp.size.bytes":-1,"time.cost.milliseconds":274,"current.thread.name":"main","remote.app":"","baggage":""}
{"time":"2018-09-27 20:31:22.443","local.app":"HttpClientDemo","traceId":"0a0fe8801538051482410100233277","spanId":"0","request.url":"http://localhost:8080/httpclient","method":"GET","result.code":"200","req.size.bytes":0,"resp.size.bytes":-1,"time.cost.milliseconds":33,"current.thread.name":"I/O dispatcher 1","remote.app":"","baggage":""}