java9中gc log参数迁移

 更新时间:2018年03月02日 08:44:20   转载 作者:codecraft  
本篇文章给大家详细讲述了java9中gc log参数迁移的相关知识点,对此有需要的朋友可以参考学习下。


本文主要研究一下java9 gc log参数的迁移。

统一JVM及GC的Logging

java9引进了一个统一的日志框架,把gc相关的log输出及配置也给纳入进来了。

相关JEP(JDK Enhancement Proposal)

Xlog语法

-Xlog[:option]
  option     := [<what>][:[<output>][:[<decorators>][:<output-options>]]]
            'help'
            'disable'
  what      := <selector>[,...]
  selector    := <tag-set>[*][=<level>]
  tag-set    := <tag>[+...]
            'all'
  tag      := name of tag
  level     := trace
            debug
            info
            warning
            error
  output     := 'stderr'
            'stdout'
            [file=]<filename>
  decorators   := <decorator>[,...]
            'none'
  decorator   := time
            uptime
            timemillis
            uptimemillis
            timenanos
            uptimenanos
            pid
            tid
            level
            tags
  output-options := <output_option>[,...]
  output-option := filecount=<file count>
            filesize=<file size in kb>
            parameter=value

what

主要是配置tag及level

tag

其中all代表所有的tag,其他的如下:

add,age,alloc,annotation,aot,arguments,attach,barrier,biasedlocking,blocks,bot,breakpoint,bytecode,census,class,classhisto,cleanup,compaction,comparator,constraints,constantpool,coops,cpu,cset,data,defaultmethods,dump,ergo,event,exceptions,exit,fingerprint,freelist,gc,hashtables,heap,humongous,ihop,iklass,init,itables,jfr,jni,jvmti,liveness,load,loader,logging,mark,marking,metadata,metaspace,method,mmu,modules,monitorinflation,monitormismatch,nmethod,normalize,objecttagging,obsolete,oopmap,os,pagesize,parser,patch,path,phases,plab,preorder,promotion,protectiondomain,purge,redefine,ref,refine,region,remset,resolve,safepoint,scavenge,scrub,setting,stackmap,stacktrace,stackwalk,start,startuptime,state,stats,stringdedup,stringtable,subclass,survivor,sweep,system,task,thread,time,timer,tlab,unload,update,verification,verify,vmoperation,vtables,workgang

level

主要分off,trace,debug,info,warning,error

output

- stdout(`Sends output to stdout`)
- stderr(`Sends output to stderr`)
- file=filename(`Sends output to text file(s)`)

有如上三种,其中指定file的话,可以使用%p变量表示当前jvm的pid,用%t表示jvm的启动时间戳。比如

-Xlog:gc:demoapp-gc-%p-%t.log

输出的文件名如下:

demoapp-gc-1678-2018-03-01_21-44-18.log

decorators

  • time -- Current time and date in ISO-8601 format
  • uptime -- Time since the start of the JVM in seconds and milliseconds (e.g., 6.567s)
  • timemillis -- The same value as generated by System.currentTimeMillis()
  • uptimemillis -- Milliseconds since the JVM started
  • timenanos -- The same value as generated by System.nanoTime()
  • uptimenanos -- Nanoseconds since the JVM started
  • pid -- The process identifier
  • tid -- The thread identifier
  • level -- The level associated with the log message
  • tags -- The tag-set associated with the log message

不指定的话,默认是uptime, level, and tags这三个。比如

[3.080s][info][gc,cpu ] GC(5) User=0.03s Sys=0.00s Real=0.01s

实例

-Xlog:gc=trace:file=gctrace.txt:uptimemillis,pid:filecount=5,filesize=1024

tag为gc,levle为trace,rotate文件数为5,每个文件1M,文件名为gctrace.txt,decrotators为uptimemillis和pid

输出实例

[1110ms][1867] GC(2) Pause Remark 17M->17M(256M) 2.024ms
[1110ms][1867] GC(2) Finalize Live Data 0.000ms
[1110ms][1867] GC(2) Pause Cleanup 17M->17M(256M) 0.177ms
[1112ms][1867] GC(2) Concurrent Cycle 7.470ms
[2951ms][1867] GC(3) Pause Initial Mark (Metadata GC Threshold) 149M->30M(256M) 27.175ms
[2951ms][1867] GC(4) Concurrent Cycle
[2972ms][1867] GC(4) Pause Remark 32M->32M(256M) 5.132ms
[2974ms][1867] GC(4) Finalize Live Data 0.000ms
[2974ms][1867] GC(4) Pause Cleanup 32M->32M(256M) 0.214ms
[2976ms][1867] GC(4) Concurrent Cycle 25.422ms

迁移

旧版GC相关参数迁移

Legacy Garbage Collection (GC) Flag Xlog Configuration Comment
G1PrintHeapRegions -Xlog:gc+region=trace Not Applicable
GCLogFileSize No configuration available Log rotation is handled by the framework.
NumberOfGCLogFiles Not Applicable Log rotation is handled by the framework.
PrintAdaptiveSizePolicy -Xlog:ergo*=level Use a level of debug for most of the information, or a level of trace for all of what was logged for PrintAdaptiveSizePolicy.
PrintGC -Xlog:gc Not Applicable
PrintGCApplicationConcurrentTime -Xlog:safepoint Note that PrintGCApplicationConcurrentTime and PrintGCApplicationStoppedTime are logged on the same tag and aren't separated in the new logging.
PrintGCApplicationStoppedTime -Xlog:safepoint Note that PrintGCApplicationConcurrentTime and PrintGCApplicationStoppedTime are logged on the same tag and not separated in the new logging.
PrintGCCause Not Applicable GC cause is now always logged.
PrintGCDateStamps Not Applicable Date stamps are logged by the framework.
PrintGCDetails -Xlog:gc* Not Applicable
PrintGCID Not Applicable GC ID is now always logged.
PrintGCTaskTimeStamps -Xlog:task*=debug Not Applicable
PrintGCTimeStamps Not Applicable Time stamps are logged by the framework.
PrintHeapAtGC -Xlog:gc+heap=trace Not Applicable
PrintReferenceGC -Xlog:ref*=debug Note that in the old logging, PrintReferenceGC had an effect only if PrintGCDetails was also enabled.
PrintStringDeduplicationStatistics -Xlog:stringdedup*=debug Not Applicable
PrintTenuringDistribution -Xlog:age*=level Use a level of debug for the most relevant information, or a level of trace for all of what was logged for PrintTenuringDistribution.
UseGCLogFileRotation Not Applicable What was logged for PrintTenuringDistribution.

旧版运行时参数迁移

Legacy Runtime Flag Xlog Configuration Comment
TraceExceptions -Xlog:exceptions=info Not Applicable
TraceClassLoading -Xlog:class+load=level Use level=info for regular information, or level=debug for additional information. In Unified Logging syntax, -verbose:class equals -Xlog:class+load=info,class+unload=info.
TraceClassLoadingPreorder -Xlog:class+preorder=debug Not Applicable
TraceClassUnloading -Xlog:class+unload=level Use level=info for regular information, or level=trace for additional information. In Unified Logging syntax, -verbose:class equals -Xlog:class+load=info,class+unload=info.
VerboseVerification -Xlog:verification=info Not Applicable
TraceClassPaths -Xlog:class+path=info Not Applicable
TraceClassResolution -Xlog:class+resolve=debug Not Applicable
TraceClassInitialization -Xlog:class+init=info Not Applicable
TraceLoaderConstraints -Xlog:class+loader+constraints=info Not Applicable
TraceClassLoaderData -Xlog:class+loader+data=level Use level=debug for regular information or level=trace for additional information.
TraceSafepointCleanupTime -Xlog:safepoint+cleanup=info Not Applicable
TraceSafepoint -Xlog:safepoint=debug Not Applicable
TraceMonitorInflation -Xlog:monitorinflation=debug Not Applicable
TraceBiasedLocking -Xlog:biasedlocking=level Use level=info for regular information, or level=trace for additional information.
TraceRedefineClasses -Xlog:redefine+class*=level level=info, =debug, and =trace provide increasing amounts of information.

小结

java9把gc log的选型及输出也给统一到了Xlog中,可以按照官方给出的迁移表进行迁移。

相关文章

  • 细数Java接口的概念、分类及与抽象类的区别

    细数Java接口的概念、分类及与抽象类的区别

    下面小编就为大家带来一篇细数Java接口的概念、分类及与抽象类的区别。小编觉得挺不错的,现在就分享给大家,也给大家做个参考。一起跟随小编过来看看吧
    2016-11-11
  • Java实现单例模式之饿汉式、懒汉式、枚举式

    Java实现单例模式之饿汉式、懒汉式、枚举式

    本篇文章主要介绍了Java实现单例的3种普遍的模式,饿汉式、懒汉式、枚举式。具有一定的参考价值,感兴趣的小伙伴们可以参考一下。
    2016-10-10
  • java数组基础详解

    java数组基础详解

    这篇文章主要介绍了Java数组基础详解,具有一定参考价值,需要的朋友可以了解下。
    2017-11-11
  • java8 LocalDate LocalDateTime等时间类用法实例分析

    java8 LocalDate LocalDateTime等时间类用法实例分析

    这篇文章主要介绍了java8 LocalDate LocalDateTime等时间类用法,结合具体实例形式分析了LocalDate、LocalTime、LocalDateTime等日期时间相关类的功能与具体使用技巧,需要的朋友可以参考下
    2017-04-04
  • Java编写的24点纸牌游戏

    Java编写的24点纸牌游戏

    这篇文章主要介绍了Java编写的24点纸牌游戏的相关资料,需要的朋友可以参考下
    2015-03-03
  • Spring中配置数据源的几种方式

    Spring中配置数据源的几种方式

    今天小编就为大家分享一篇关于Spring中配置数据源的几种方式,小编觉得内容挺不错的,现在分享给大家,具有很好的参考价值,需要的朋友一起跟随小编来看看吧
    2019-01-01
  • Spring boot集成RabbitMQ的示例代码

    Spring boot集成RabbitMQ的示例代码

    本篇文章主要介绍了Spring boot集成RabbitMQ的示例代码,小编觉得挺不错的,现在分享给大家,也给大家做个参考。一起跟随小编过来看看吧
    2018-05-05
  • java读取excel文件的两种方法

    java读取excel文件的两种方法

    这篇文章主要为大家详细介绍了java读取excel文件的两种方法,具有一定的参考价值,感兴趣的小伙伴们可以参考一下
    2017-08-08
  • SpringBoot拦截器Filter的使用方法详解

    SpringBoot拦截器Filter的使用方法详解

    这篇文章主要介绍了SpringBoot拦截器Filter的使用方法详解,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下
    2020-03-03
  • Springboot+echarts实现可视化

    Springboot+echarts实现可视化

    这篇文章主要为大家详细介绍了Springboot+echarts实现可视化,文中示例代码介绍的非常详细,具有一定的参考价值,感兴趣的小伙伴们可以参考一下
    2019-12-12

最新评论