不知道大家有没有一堆日志就是定位不到那块是异常部分,接口错误无法复现,也找不到报错信息等比较棘手的问题。
其实解决上面的问题很简单,只要我们为每一个请求都分配一个唯一的 RequestId 或者叫 TraceId ,一旦出了问题,只需要拿着 Id 去日志里一搜,妖魔鬼怪立马原形毕露。
对于分布式链路追踪,有很多开源中间件,本文主要通过 logback 的 MDC 实现。
请求拦截器
@Component
public class TraceIdInterceptor extends HandlerInterceptorAdapter {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
String traceId = String.format("%s - %s",request.getRequestURI(), UUID.fastUUID().toString(true));
MDC.put("traceId", traceId);
return true;
}
注册拦截器
@Component
@RequiredArgsConstructor
public class GlobalWebMvcConfigurer implements WebMvcConfigurer {
private final TraceIdInterceptor traceIdInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(traceIdInterceptor);
}
}
统一返回值
@Data
@NoArgsConstructor
@AllArgsConstructor
public class CommonResponse<T> implements Serializable {
/** 错误码 */
private Integer code;
/** 错误消息 */
private String message;
/** 泛型响应数据 */
private T Data;
private String traceId;
public CommonResponse(Integer code, String message) {
this.code = code;
this.message = message;
this.traceId = MDC.get("traceId");
}
}
日志配置
logback.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<property name="LOG_PATTERN"
value="%d{yyyy-MM-dd} %d{HH:mm:ss.SSS} [%highlight(%-5level)] [%boldYellow(%X{traceId})] [%boldYellow(%thread)] %boldGreen(%logger{36} %F.%L) %msg%n">
</property>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>${LOG_PATTERN}</pattern>
</encoder>
<!-- 控制台打印INFO及以上级别的日志 -->
<filter class="ch.qos.logback.classic.filter.ThresholdFilter">
<level>INFO</level>
</filter>
</appender>
<root>
<appender-ref ref="STDOUT"/>
</root>
</configuration>
测试
接口返回值
{
"code": 0,
"message": "",
"traceId": "/commerce-user/user/findById - 73e470120ef24d57a111de6b671d030b",
"data": {
"id": 1,
"username": "test1",
"password": "test",
"extraInfo": "{}",
"createTime": "2022-06-20T09:23:18.000+00:00",
"updateTime": "2022-06-20T09:23:18.000+00:00",
"balance": 0
}
}
日志
如此,如果线上有接口出现问题,拿着 traceId 到日志文件搜索,就能检索到该请求的日志调用链路,处理问题就变得简单了。
异步调用配置
因为是 ThreadLocal ,异步任务必然是获取不到 traceId 的,需要再线程池配置中手动添加。
线程池配置
@Configuration
public class AsyncConfig implements AsyncConfigurer {
@Bean
@Override
public Executor getAsyncExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(10);
executor.setMaxPoolSize(20);
executor.setQueueCapacity(20);
executor.setKeepAliveSeconds(60);
executor.setThreadNamePrefix("user-async-");
// 等待所有任务结果候再关闭线程池
executor.setWaitForTasksToCompleteOnShutdown(true);
executor.setAwaitTerminationSeconds(60);
// 定义拒绝策略
executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
//设置线程装饰器
executor.setTaskDecorator(runnable -> ThreadMdcUtils.wrapAsync(runnable, MDC.getCopyOfContextMap()));
// 初始化线程池, 初始化 core 线程
executor.initialize();
return executor;
}
}
public class ThreadMdcUtils {
public static Runnable wrapAsync(Runnable task, Map<String,String> context){
return () -> {
if(context==null){
MDC.clear();
}else {
MDC.setContextMap(context);
}
if(MDC.get("traceId")==null){
MDC.put("traceId", UUID.fastUUID().toString(true));
}
try {
task.run();
}finally {
MDC.clear();
}
};
}
}
再次测试