Distributed tracing and usage in Spring Boot

Distributed tracing and usage in Spring Boot

With the increasing complexity of Internet applications, distributed systems have become the standard configuration of many enterprise-level applications. In a distributed system, due to the intricate invocation relationship between services, it is difficult to trace the execution path and time of a request in the entire system, which brings great challenges to troubleshooting and performance optimization. In order to solve this problem, distributed tracking technology came into being. This article will introduce the distributed tracing technology in Spring Boot and how to use it.

The concept of distributed tracing

Distributed Tracing (Distributed Tracing) is a technique used to trace the execution path and time of requests in a distributed system. In a distributed system, since the request may pass through multiple service nodes, it is necessary to add a unique identifier (Trace ID) in the request process and pass the Trace ID to all relevant service nodes. When each service node processes a request, it needs to record the Trace ID in the context of the request, and pass the context information of the request to the next service node. In this way, the execution path and time of a request in the entire system can be traced through the Trace ID. During the tracking process, it is also necessary to record the time and time spent on processing requests by each service node in order to analyze and optimize system performance.

Spring Cloud Sleuth

Spring Cloud Sleuth is a distributed tracking framework in Spring Cloud. It provides a request tracking function based on Trace ID, which can help developers quickly track the request execution path and time in a distributed system, and help troubleshoot problems and optimize performance.

Spring Cloud Sleuth uses Zipkin to store and display distributed tracing information. Zipkin is an open source distributed tracing system that can be used to store and display request tracing information in distributed systems.

Distributed Tracing in Spring Boot

Spring Boot integrates Spring Cloud Sleuth, which makes it very convenient to implement distributed tracing. In a Spring Boot application, only the following dependencies need to be added:

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-sleuth</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-zipkin</artifactId>
</dependency>

With these dependencies added, a Spring Boot application can automatically configure distributed tracing and send tracing information to a Zipkin server.

In the application, you can Tracercreate a Trace ID through the interface, and record the Trace ID in the context of the request:

@Autowired
private Tracer tracer;

@GetMapping("/hello")
public String hello() {
    
    
    Span span = tracer.nextSpan().name("hello").start();
    try (Tracer.SpanInScope ws = tracer.withSpan(span)) {
    
    
        // 处理请求
        return "Hello World!";
    } finally {
    
    
        span.finish();
    }
}

In each service node, the Trace ID needs to be recorded in the context of the request, and the context information of the request is passed to the next service node. Spring Boot can automatically pass the context information of the request through RestTemplateand Feign, just add the corresponding configuration in RestTemplateand :Feign

@Bean
public RestTemplate restTemplate() {
    
    
    return new RestTemplateBuilder()
            .interceptors(new TraceRestTemplateInterceptor(tracer()))
            .build();
}

@Bean
public Feign.Builder feignBuilder() {
    
    
    return Feign.builder().requestInterceptor(new TraceFeignRequestInterceptor(tracer()));
}

Use of Zipkin

Zipkin is a system for storing and displaying distributed tracing information, which can be used to analyze and optimize the performance of distributed systems. In Spring Boot, Zipkin can be used through the following steps:

1. Download and start the Zipkin server

You can download the Zipkin server from Zipkin's official website and start the Zipkin server. http://localhost:9411After starting the Zipkin server, you can view Zipkin's web interface by visiting in your browser .

2. Configure Spring Boot application to send trace information to Zipkin server

In a Spring Boot application, the following configuration can be used to send trace information to the Zipkin server:

spring:
  zipkin:
    base-url: http://localhost:9411

3. View Distributed Tracing Information

After starting a Spring Boot application, you can fire off requests by accessing the application's endpoints and view distributed trace information in Zipkin's web interface. In Zipkin's web interface, you can view information such as the Trace ID of each request, the service node in the request process, the execution time and time-consuming of the service node.

Summarize

Distributed tracing technology is one of the key technologies to solve the problem that the request execution path and time cannot be traced in a distributed system. Spring Boot integrates Spring Cloud Sleuth and Zipkin, making distributed tracing very simple. In the Spring Boot application, you can implement the distributed tracking function by adding corresponding dependencies and configurations, and send the tracking information to the Zipkin server. Using distributed tracing technology can help developers better manage and monitor distributed systems, and improve system reliability and performance.