这段时间的面试，遇到好多问日志管理的，今天我就一起聊聊，本地日志输出和全链路日志配置
目标：介绍我们框架中使用的本地日志系统及全链路日志系统。本地日志使用spring推荐的logbak，基本是零配置的形式。全链路日志追踪也叫分布式日志，使用zipkin。原理很简单：
1、各模块集成zipkin日志收集功能，日志打在kafka中（生产者）；
2、zipkin管理端会上来搜刮kafka（消费者），并使用elasticsearch保存日志；
3、使用zipkin ui或kabana展示，在之前的我接触的项目中我们两者都用了
一、本地日志输出配置
1. 新增日志配置文件[src/main/resources/logback-spring.xml]
必须使用这个配置，这是需要事先和运维约定好，日志文件的格式、存放路径、存放周期、命名等都有要求，不要自己再去撸一个运维不认的
注意这个地方用到了一个变量${app.dir}，必须先设置值。
有两种方式，第一种就是引入我们已经封装好项目模块，pom.xml引入就好了，目前是0.0.2版本。
另外一种方式就是自己撸代码，在自己的启动类中加入以下java代码。
log.info("初始化System.setProperty(\"app.dir\")");
String userDir = System.getProperty("user.dir");
System.setProperty("app.dir",
userDir.substring(userDir.lastIndexOf(File.separator)));
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<property name="CONSOLE_LOG_PATTERN"
value="%clr(%d{yyyy-MM-dd HH:mm:ss.SSS}){faint} %clr(${LOG_LEVEL_PATTERN:-%5p}) %clr(${PID:- }){magenta} %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:[%L]){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:-%wEx}"/>
<property name="FILE_LOG_PATTERN"
value="${FILE_LOG_PATTERN:-%d{yyyy-MM-dd HH:mm:ss.SSS} ${LOG_LEVEL_PATTERN:-%5p} ${PID:- } --- [%t] %-40.40logger{39} :[%L] %m%n${LOG_EXCEPTION_CONVERSION_WORD:-%wEx}}"/>
<property name="LOG_PATH" value="/log/web/${app.dir}"/>
<property name="LOG_FILE" value="${LOG_FILE:-${LOG_PATH:-${LOG_TEMP:-${java.io.tmpdir:-/tmp}}}/${app.dir}-info}"/>
<include resource="org/springframework/boot/logging/logback/defaults.xml"/>
<include resource="org/springframework/boot/logging/logback/console-appender.xml"/>
<appender name="FILE"
class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>${LOG_FILE}.log</file>
<rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
<!-- rollover daily -->
<fileNamePattern>${LOG_FILE}-%d{yyyy-MM-dd-HH00}.%i.log</fileNamePattern>
<!-- each file should be at most 100MB, keep 15 days worth of history, but at most 20GB -->
<maxFileSize>100MB</maxFileSize>
<maxHistory>360</maxHistory>
<totalSizeCap>20GB</totalSizeCap>
</rollingPolicy>
<encoder>
<pattern>${FILE_LOG_PATTERN}</pattern>
</encoder>
</appender>
<logger name="org.springframework.security" level="DEBUG"/>
<logger name="org.springframework.cloud.sleuth.instrument.web.client.feign.TraceFeignClient" level="DEBUG"/>
<logger name="org.springframework.web.servlet.DispatcherServlet" level="DEBUG"/>
<logger name="org.springframework.cloud.sleuth.instrument.web.TraceFilter" level="DEBUG"/>
<logger name="com.jarvis.cache" level="DEBUG"/>
<logger name="com.youli" level="DEBUG"/>
<logger name="org.springframework.security.web.util.matcher" level="INFO"/>
<root level="INFO">
<appender-ref ref="CONSOLE"/>
<appender-ref ref="FILE"/>
</root>
</configuration>
2. 在spring boot的启动类中增加环境变量设置代码
public static void main(String[] args) {
//只要增加下面两行就行了，为了获取当前jar包所在的目录。日志文件将输出在/log/web/{app.dir}下面
String userDir = System.getProperty("user.dir");
System.setProperty("app.dir", userDir.substring(userDir.lastIndexOf(File.separator)));
//End
SpringApplication.run(AppGatewayApplication.class, args);
}
3. 代码逻辑，lombok的搞法。
lombok是个很好用的工具包，比如@Setter@Getter之类的，话题太长，不懂的度娘扫盲下。
安装也很简单，去官网下载个jar包，本地java -jar运行就好了。
pom.xml引入lombok依赖
<!--lombok工具-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
在Class上加上注解@Slf4j，然后日志就可以开心的打日志了
package com.youli.demo.controller;
import javax.servlet.http.HttpServletRequest;
import org.slf4j.LoggerFactory;
import org.slf4j.Logger;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@Slf4j//这个注解加上
@RequestMapping(value="/demo/log")
public class LogController {
//这行代码不要了
//private final Logger logger = LoggerFactory.getLogger(this.getClass());
@RequestMapping(value="/logMe")
public String logMe(HttpServletRequest request) {
String a = request.getParameter("a");
String b = request.getParameter("b");
// 日志输出禁止使用字符串拼接，应该使用占位符的方式
// 以防止级别调高性能依然消耗的情况
//logger.debug("params: a={}, b={}", a, b);
//logger没有了，用@Slf4j注进来的log
log.debug("params: a={}, b={}", a, b);
return "ok";
}
}
程序启动后在D:\log\web\[你的工程目录名]能看到日志了
3.日志场景
接口访问404
修改日志配置文件[src/main/resources/logback-spring.xml]，添加配置将RequestMappingHandlerMapping类设置为debug输出
<logger name="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping" level="DEBUG" />
这样当出现404错误的时候服务端日志就能看见如下输出：
2017-12-14 11:35:17.691 DEBUG 4484 --- [nio-9050-exec-1] s.w.s.m.m.a.RequestMappingHandlerMapping : Looking up handler method for path /abcdsdfsdf
2017-12-14 11:35:17.694 DEBUG 4484 --- [nio-9050-exec-1] s.w.s.m.m.a.RequestMappingHandlerMapping : Did not find handler method for [/abcdsdfsdf]
2017-12-14 11:35:17.699 DEBUG 4484 --- [nio-9050-exec-1] s.w.s.m.m.a.RequestMappingHandlerMapping : Looking up handler method for path /error
2017-12-14 11:35:17.701 DEBUG 4484 --- [nio-9050-exec-1] s.w.s.m.m.a.RequestMappingHandlerMapping : Returning handler method [public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)]
二、全链路日志配置
1.目标
简单两个步骤的配置就搞定了，配置成功的标志是-日志输出带全局traceID，长下面这个样子的（[bootstrap,948cb6650eb020a6,948cb6650eb020a6,true]这个就是全局traceID和spanID了）
2017-12-15 15:07:55.570 INFO [bootstrap,948cb6650eb020a6,948cb6650eb020a6,true] 5856 --- [nio-9001-exec-1] s.c.a.AnnotationConfigApplicationContext :[583] Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@40c35b01: startup date [Fri Dec 15 15:07:55 CST 2017]; parent: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@162be91c
2017-12-15 15:07:55.636 INFO [bootstrap,948cb6650eb020a6,948cb6650eb020a6,true] 5856 --- [nio-9001-exec-1] f.a.AutowiredAnnotationBeanPostProcessor :[155] JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
2017-12-15 15:07:55.920 INFO [bootstrap,948cb6650eb020a6,948cb6650eb020a6,true] 5856 --- [nio-9001-exec-1] c.netflix.config.ChainedDynamicProperty :[115] Flipping property: common-external-platform.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2017-12-15 15:07:55.945 INFO [bootstrap,948cb6650eb020a6,948cb6650eb020a6,true] 5856 --- [nio-9001-exec-1] c.n.u.concurrent.ShutdownEnabledTimer :[58] Shutdown hook installed for: NFLoadBalancer-PingTimer-common-external-platform
2017-12-15 15:07:55.965 INFO [bootstrap,948cb6650eb020a6,948cb6650eb020a6,true] 5856 --- [nio-9001-exec-1] c.netflix.loadbalancer.BaseLoadBalancer :[192] Client: common-external-platform instantiated a LoadBalancer: DynamicServerListLoadBalancer:{NFLoadBalancer:name=common-external-platform,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:null
2017-12-15 15:07:55.971 INFO [bootstrap,948cb6650eb020a6,948cb6650eb020a6,true] 5856 --- [nio-9001-exec-1] c.n.l.DynamicServerListLoadBalancer :[214] Using serverListUpdater PollingServerListUpdater
2017-12-15 15:07:55.999 INFO [bootstrap,948cb6650eb020a6,948cb6650eb020a6,true] 5856 --- [nio-9001-exec-1] c.netflix.config.ChainedDynamicProperty :[115] Flipping property: common-external-platform.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2017-12-15 15:07:56.001 INFO [bootstrap,948cb6650eb020a6,948cb6650eb020a6,true] 5856 --- [nio-9001-exec-1] c.n.l.DynamicServerListLoadBalancer :[150] DynamicServerListLoadBalancer for client common-external-platform initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=common-external-platform,current list of Servers=[10.18.2.82:9050, 10.18.2.81:9050],Load balancer stats=Zone stats: {defaultzone=[Zone:defaultzone; Instance count:2; Active connections count: 0; Circuit breaker tripped count: 0; Active connections per server: 0.0;]
2.步骤
1.修改配置文件[pom.xml] 添加zipkin依赖库
<!--全链路日志追踪zipkin,kafka收集-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-sleuth-zipkin-stream</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-stream-kafka</artifactId>
</dependency>
2.修改配置文件[src/main/resources/application.yml] 配置kafka和ZK节点信息(注意：这个配置是SIT的)，配置sleuth采样率为1（100%采样）
spring:
cloud:
stream:
kafka:
binder:
brokers: 192.167.1.3:9092,192.168.1.4:9092,192.168.1.5:9092
zkNodes: 192.168.1.3:2181
sleuth:
sampler:
percentage: 1.0
完了，很简单吧