jvm 虚拟机日志参数

╰+攻爆jí腚メ 2023-07-20 13:54 1阅读 0赞

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### jvm 虚拟机日志参数 ###

**官网：[https://docs.oracle.com/en/java/javase/14/docs/specs/man/java.html\#advanced-runtime-options-for-java][https_docs.oracle.com_en_java_javase_14_docs_specs_man_java.html_advanced-runtime-options-for-java]**

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**-Xlog ****命令格式**

-Xlog[:[selections][:[output][:[decorators][:output-options]]]]

**-Xlog：**开启日志输出，默认为**-Xlog:all=warning:stdout:uptime,level,tags**

**-Xlog:help：**查看-Xlog参数使用方式

**-Xlog:disable：**禁用-Xlog日志输出

**常用日志参数**

**-Xlog:gc：**输出gc日志

**-Xlog:gc\*：**输出详细gc日志

**-Xlog:gc+heap=debug：**输出gc前后堆信息，等同于-XX:+PrintHeapAtGC，java9及之后使用

**-Xlog:safepoint：**输出gc过程中用户线程并发及停顿时间

**-Xlog:gc+age=trace：**输出gc、新生代对象年龄

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**selections：tags + level，可选**

**tags**

Available log tags:
     add, age, alloc, annotation, aot, arguments, attach, barrier, biasedlocking, blocks, 
    bot, breakpoint, bytecode, cds, census, class, classhisto, cleanup, codecache, 
    compaction, compilation, constantpool, constraints, container, coops, cpu, cset, data, 
    datacreation, dcmd, decoder, defaultmethods, director, dump, dynamic, ergo, event, 
    exceptions, exit, fingerprint, free, freelist, gc, handshake, hashtables, heap, 
    humongous, ihop, iklass, init, inlining, install, interpreter, itables, jfr, jit, jni, 
    jvmti, liveness, load, loader, logging, malloc, mark, marking, membername, memops, 
    metadata, metaspace, methodcomparator, mirror, mmu, module, monitorinflation, 
    monitormismatch, nestmates, nmethod, normalize, numa, objecttagging, obsolete, oldobject, 
    oom, oopmap, oops, oopstorage, os, pagesize, parser, patch, path, perf, periodic, phases, 
    plab, preorder, preview, promotion, protectiondomain, ptrqueue, purge, record, redefine, 
    ref, refine, region, reloc, remset, resolve, safepoint, sampling, scavenge, setting, smr, 
    stackmap, stacktrace, stackwalk, start, startuptime, state, stats, streaming, 
    stringdedup, stringtable, subclass, survivor, sweep, symboltable, system, table, task, 
    thread, time, timer, tlab, tracking, unload, unshareable, update, verification, verify, 
    vmmutex, vmoperation, vmthread, vtables, vtablestubs, workgang
    
     Specifying 'all' instead of a tag combination matches all tag combinations.

**level： off, trace, debug, info, warning, error**

**示例：**

**all：**包含所有标签

**gc：**只有gc标签的日志

**gc\*：**包含gc的标签

**gc + phases：**只有gc、phrases的日志，单独的gc、phases不输出

**gc + phases\*：**输出包含gc、phases的日志

**gc=trace：**输出日志级别在trace或以上的日志

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**output：输出位置**

**stdout：**输出到控制台

**stderr：**错误输出

**file=file\_name：**输出到文件

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**decorations：日志输出格式，可选，默认为uptime，level，tags**

**time、t：**当前时间，当前时区时间，如：**\[2020-04-02T16:17:54.614+0800\]**

**utctime、utc：**通用时间，0时区时间，如：**\[2020-04-02T08:17:54.614+0000\]**

**timemills、tm：**System.currentTimeMillis()的数值，如：**\[1585815474614ms\]**

**timenanos、tn：**System.nanoTime()的数值，如：**\[108171620762600ns\]**

**uptime、u：**虚拟机启动到当前时间间隔，如：**\[0.179s\]**

**uptimemillis、um：**虚拟机启动经过的毫秒数，如：**\[171ms\]**

**uptimenanos、un：**虚拟机启动到当前经过的时间，纳秒，如：**\[108303677015300ns\]**

**hostname、hn：**主机名

**pid、p：**进程id

**tid、ti：**线程id

**level、l：**日志级别

**tags、tg：**标签名

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**示例**

public class Test {
    
        public static void main(String[] args){
            byte[] b=new byte[1024*1024];
            b=null;
    
            System.gc();
        }
    }

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**控制台输出**

**虚拟机参数：\-XX:+UseParallelGC -Xlog:gc\*:stdout:time,utc,uptime,hostname,pid,tid,level,tags**

[2020-04-02T16:30:54.480+0800][2020-04-02T08:30:54.480+0000][0.027s][LAPTOP-D73GD8TE][6480][1664][info][gc,heap,coops] Heap address: 0x0000000081c00000, size: 2020 MB, Compressed Oops mode: 32-bit
    [2020-04-02T16:30:54.483+0800][2020-04-02T08:30:54.483+0000][0.028s][LAPTOP-D73GD8TE][6480][1664][info][gc           ] Using Parallel
    [2020-04-02T16:30:54.600+0800][2020-04-02T08:30:54.600+0000][0.146s][LAPTOP-D73GD8TE][6480][4388][info][gc,start     ] GC(0) Pause Young (System.gc())
    [2020-04-02T16:30:54.602+0800][2020-04-02T08:30:54.602+0000][0.148s][LAPTOP-D73GD8TE][6480][4388][info][gc,heap      ] GC(0) PSYoungGen: 9472K(38400K)->968K(38400K) Eden: 9472K(33280K)->0K(33280K) From: 0K(5120K)->968K(5120K)
    [2020-04-02T16:30:54.602+0800][2020-04-02T08:30:54.602+0000][0.148s][LAPTOP-D73GD8TE][6480][4388][info][gc,heap      ] GC(0) ParOldGen: 0K(87552K)->8K(87552K)
    [2020-04-02T16:30:54.602+0800][2020-04-02T08:30:54.602+0000][0.148s][LAPTOP-D73GD8TE][6480][4388][info][gc,metaspace ] GC(0) Metaspace: 624K(4864K)->624K(4864K) NonClass: 566K(4352K)->566K(4352K) Class: 58K(512K)->58K(512K)
    [2020-04-02T16:30:54.602+0800][2020-04-02T08:30:54.602+0000][0.148s][LAPTOP-D73GD8TE][6480][4388][info][gc           ] GC(0) Pause Young (System.gc()) 9M->0M(123M) 1.999ms
    [2020-04-02T16:30:54.602+0800][2020-04-02T08:30:54.602+0000][0.148s][LAPTOP-D73GD8TE][6480][4388][info][gc,cpu       ] GC(0) User=0.00s Sys=0.00s Real=0.00s
    [2020-04-02T16:30:54.602+0800][2020-04-02T08:30:54.602+0000][0.148s][LAPTOP-D73GD8TE][6480][4388][info][gc,start     ] GC(1) Pause Full (System.gc())
    [2020-04-02T16:30:54.602+0800][2020-04-02T08:30:54.602+0000][0.148s][LAPTOP-D73GD8TE][6480][4388][info][gc,phases,start] GC(1) Marking Phase
    [2020-04-02T16:30:54.604+0800][2020-04-02T08:30:54.604+0000][0.149s][LAPTOP-D73GD8TE][6480][4388][info][gc,phases      ] GC(1) Marking Phase 1.591ms
    [2020-04-02T16:30:54.604+0800][2020-04-02T08:30:54.604+0000][0.150s][LAPTOP-D73GD8TE][6480][4388][info][gc,phases,start] GC(1) Summary Phase
    [2020-04-02T16:30:54.604+0800][2020-04-02T08:30:54.604+0000][0.150s][LAPTOP-D73GD8TE][6480][4388][info][gc,phases      ] GC(1) Summary Phase 0.015ms
    [2020-04-02T16:30:54.604+0800][2020-04-02T08:30:54.604+0000][0.150s][LAPTOP-D73GD8TE][6480][4388][info][gc,phases,start] GC(1) Adjust Roots
    [2020-04-02T16:30:54.605+0800][2020-04-02T08:30:54.605+0000][0.150s][LAPTOP-D73GD8TE][6480][4388][info][gc,phases      ] GC(1) Adjust Roots 0.652ms
    [2020-04-02T16:30:54.605+0800][2020-04-02T08:30:54.605+0000][0.150s][LAPTOP-D73GD8TE][6480][4388][info][gc,phases,start] GC(1) Compaction Phase
    [2020-04-02T16:30:54.607+0800][2020-04-02T08:30:54.607+0000][0.153s][LAPTOP-D73GD8TE][6480][4388][info][gc,phases      ] GC(1) Compaction Phase 2.365ms
    [2020-04-02T16:30:54.607+0800][2020-04-02T08:30:54.607+0000][0.153s][LAPTOP-D73GD8TE][6480][4388][info][gc,phases,start] GC(1) Post Compact
    [2020-04-02T16:30:54.607+0800][2020-04-02T08:30:54.607+0000][0.153s][LAPTOP-D73GD8TE][6480][4388][info][gc,phases      ] GC(1) Post Compact 0.048ms
    [2020-04-02T16:30:54.607+0800][2020-04-02T08:30:54.607+0000][0.153s][LAPTOP-D73GD8TE][6480][4388][info][gc,heap        ] GC(1) PSYoungGen: 968K(38400K)->0K(38400K) Eden: 0K(33280K)->0K(33280K) From: 968K(5120K)->0K(5120K)
    [2020-04-02T16:30:54.607+0800][2020-04-02T08:30:54.607+0000][0.153s][LAPTOP-D73GD8TE][6480][4388][info][gc,heap        ] GC(1) ParOldGen: 8K(87552K)->925K(87552K)
    [2020-04-02T16:30:54.607+0800][2020-04-02T08:30:54.607+0000][0.153s][LAPTOP-D73GD8TE][6480][4388][info][gc,metaspace   ] GC(1) Metaspace: 624K(4864K)->624K(4864K) NonClass: 566K(4352K)->566K(4352K) Class: 58K(512K)->58K(512K)
    [2020-04-02T16:30:54.607+0800][2020-04-02T08:30:54.607+0000][0.153s][LAPTOP-D73GD8TE][6480][4388][info][gc             ] GC(1) Pause Full (System.gc()) 0M->0M(123M) 4.869ms
    [2020-04-02T16:30:54.607+0800][2020-04-02T08:30:54.607+0000][0.153s][LAPTOP-D73GD8TE][6480][4388][info][gc,cpu         ] GC(1) User=0.00s Sys=0.00s Real=0.01s
    [2020-04-02T16:30:54.608+0800][2020-04-02T08:30:54.608+0000][0.153s][LAPTOP-D73GD8TE][6480][1664][info][gc,heap,exit   ] Heap
    [2020-04-02T16:30:54.608+0800][2020-04-02T08:30:54.608+0000][0.154s][LAPTOP-D73GD8TE][6480][1664][info][gc,heap,exit   ]  PSYoungGen      total 38400K, used 1664K [0x00000000d5f00000, 0x00000000d8980000, 0x0000000100000000)
    [2020-04-02T16:30:54.608+0800][2020-04-02T08:30:54.608+0000][0.154s][LAPTOP-D73GD8TE][6480][1664][info][gc,heap,exit   ]   eden space 33280K, 5% used [0x00000000d5f00000,0x00000000d60a01e8,0x00000000d7f80000)
    [2020-04-02T16:30:54.608+0800][2020-04-02T08:30:54.608+0000][0.154s][LAPTOP-D73GD8TE][6480][1664][info][gc,heap,exit   ]   from space 5120K, 0% used [0x00000000d7f80000,0x00000000d7f80000,0x00000000d8480000)
    [2020-04-02T16:30:54.608+0800][2020-04-02T08:30:54.608+0000][0.154s][LAPTOP-D73GD8TE][6480][1664][info][gc,heap,exit   ]   to   space 5120K, 0% used [0x00000000d8480000,0x00000000d8480000,0x00000000d8980000)
    [2020-04-02T16:30:54.608+0800][2020-04-02T08:30:54.608+0000][0.154s][LAPTOP-D73GD8TE][6480][1664][info][gc,heap,exit   ]  ParOldGen       total 87552K, used 925K [0x0000000081c00000, 0x0000000087180000, 0x00000000d5f00000)
    [2020-04-02T16:30:54.608+0800][2020-04-02T08:30:54.608+0000][0.154s][LAPTOP-D73GD8TE][6480][1664][info][gc,heap,exit   ]   object space 87552K, 1% used [0x0000000081c00000,0x0000000081ce76d0,0x0000000087180000)
    [2020-04-02T16:30:54.608+0800][2020-04-02T08:30:54.608+0000][0.154s][LAPTOP-D73GD8TE][6480][1664][info][gc,heap,exit   ]  Metaspace       used 627K, capacity 4531K, committed 4864K, reserved 1056768K
    [2020-04-02T16:30:54.608+0800][2020-04-02T08:30:54.608+0000][0.154s][LAPTOP-D73GD8TE][6480][1664][info][gc,heap,exit   ]   class space    used 58K, capacity 402K, committed 512K, reserved 1048576K

[https_docs.oracle.com_en_java_javase_14_docs_specs_man_java.html_advanced-runtime-options-for-java]: https://docs.oracle.com/en/java/javase/14/docs/specs/man/java.html#advanced-runtime-options-for-java