基础概述
对于log4j2的同步和异步的讲解,本人也是找了很多的资料,也阅读了官方的文档和源码。
对于两者的区别已经log执行流程可参考,讲的挺全面的。
https://www.cnblogs.com/yeyang/p/7944906.html
其中对于AsyncAppender和AsyncLogger源码的解读可参考:
https://www.cnblogs.com/lewis09/p/10003462.html
https://www.cnblogs.com/lewis09/p/10004117.html
Disruptor详解请参考:
https://www.jianshu.com/p/bad7b4b44e48
配置优化
本文是对之前那篇log4j2异步将log发送到kafka(https://blog.csdn.net/qq_35754073/article/details/103386177)的补充和log4j2在高并发情况下的优化。
1.给log增加tracking_id,对每次请求的log作标识。
2.Loggers的配置从大部分配在root改为配置在logger,因为陪在root发现会有一些不是项目中的log发送到了kafka,而logger就很精准。
3.增加Disruptor队列长度并配置队列堵塞丢弃策略从而增加高并发下的性能
添加tracking_id:
String tracingId = request.getHeader("tracing_id");
if (tracingId == null || tracingId.isEmpty()) {
tracingId = UUID.randomUUID().toString();
}
MDC.put("tracking_id", tracingId);
代码中直接使用:
因为MDC是线程安全的,每个线程都有唯一的一个,所以我们直接使用就可以了
String tracingId = MDC.get(Constant.TRACKING_ID);
在log4j2输出log的时候默认输出tracing_id:
Configuration:
Properties:
Property:
- name: log-path
value: "logs"
- name: charset
value: "UTF-8"
- name: log.pattern
value: "%d{yyyy-MM-dd HH:mm:ss.SSS} -%5p ${PID:-} [%X{tracking_id}] [%15.15t] %-30.30C{1.} : %m%n"
Appenders:
Console:
name: CONSOLE
target: SYSTEM_OUT
PatternLayout:
pattern: ${log.pattern}
RollingFile:
- name: REQUEST_LOG
fileName: ${log-path}/request.log
filePattern: "${log-path}/historyLog/info-%d{yyyy-MM-dd}-%i.log.gz"
Filters:
ThresholdFilter:
- level: error
onMatch: DENY
onMismatch: NEUTRAL
- level: warn
onMatch: DENY
onMismatch: NEUTRAL
- level: info
onMatch: ACCEPT
onMismatch: DENY
JsonLayout:
- charset: ${charset}
compact: ${compact}
complete: ${complete}
stacktraceAsString: ${stacktraceAsString}
eventEol: ${eventEol}
properties: true
KeyValuePair:
- key: tags
value: REQUEST_LOG
Policies:
TimeBasedTriggeringPolicy:
interval: 1
modulate: true
DefaultRolloverStrategy:
max: 100
- name: REQUEST_LOG
#下面是输出PatternLayout
# fileName: ${log-path}/request.log
# filePattern: "${log-path}/historyLog/info-%d{yyyy-MM-dd}-%i.log.gz"
# PatternLayout:
# charset: ${charset}
# pattern: ${log.pattern}
# Filters:
# ThresholdFilter:
# - level: error
# onMatch: DENY
# onMismatch: NEUTRAL
# - level: warn
# onMatch: DENY
# onMismatch: NEUTRAL
# - level: debug
# onMatch: ACCEPT
# onMismatch: DENY
# Policies:
# TimeBasedTriggeringPolicy:
# interval: 1
# modulate: true
# DefaultRolloverStrategy:
# max: 100
Loggers:
AsyncRoot:
level: debug
# add location in async
includeLocation: true
AppenderRef:
- ref: CONSOLE
AsyncLogger:
- name: REQUEST_LOG
AppenderRef:
- ref: REQUEST_LOG
Loggers全部改为AsyncLogger:
Loggers:
AsyncRoot:
level: debug
# add location in async
includeLocation: true
AppenderRef:
- ref: CONSOLE
AsyncLogger:
- name: REQUEST_LOG
AppenderRef:
- ref: REQUEST_LOG
- name: SERVICE_LOG
AppenderRef:
- ref: SERVICE_LOG
- name: ERROR_LOG
AppenderRef:
- ref: ERROR_LOG
代码中使用:
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
public interface NeuralyzerLog {
Logger requestLog = LogManager.getLogger("REQUEST_LOG");
Logger serviceLog = LogManager.getLogger("SERVICE_LOG");
Logger errorLog = LogManager.getLogger("ERROR_LOG");
}
增加Disruptor队列长度并配置队列堵塞丢弃策略:
需要更改System Property(系统参数)
log4j2.asyncLoggerRingBufferSize:指定队列的长度
log4j2.AsyncQueueFullPolicy:指定堵塞丢弃策略,如果未指定此属性或具有value "Default"
,则此工厂创建DefaultAsyncQueueFullPolicy
对象。如果此属性具有value "Discard"
,则此工厂将创建 DiscardingAsyncQueueFullPolicy
对象。默认情况下,如果队列已满,此路由器将丢弃级别为INFO,DEBUG和TRACE的事件。可以使用属性log4j2.DiscardThreshold
(开始丢弃的级别名称)进行调整。
更详细的参数请参考官网:
https://logging.apache.org/log4j/2.x/manual/async.html
指定System Property(系统参数)的方式:
1.启动参数方式
启动的时候增加-Dlog4j2.asyncLoggerRingBufferSize=123456789
2.代码的方式
System.setProperty("log4j2.asyncLoggerRingBufferSize", "123456789");
3.log4j2提供的og4j2.component.properties file方式
classpath下创建og4j2.component.properties文件
log4j2.asyncLoggerRingBufferSize=123456789
log4j2.AsyncQueueFullPolicy=Discard
log4j2.AsyncQueueFullPolicy=Discard;log4j2.DiscardThreshold=INFO
如果两者都配置了,则第二种方式将会覆盖第一种方式的配置。