使用 jmap 命令 [生产环境慎用! 会造成生产环境卡顿!!!!]
调优，从规划开始
-
调优，从业务场景开始，没有业务场景的调优都是耍流氓
-
无监控（压力测试，能看到结果），不调优
-
步骤：
- 熟悉业务场景（没有最好的垃圾回收器，只有最合适的垃圾回收器）
- 响应时间、停顿时间 [CMS G1 ZGC] （需要给用户作响应）
- 吞吐量 = 用户时间 /( 用户时间 + GC时间) [PS]
- 选择回收器组合
- 计算内存需求（经验值 1.5G 16G）
- 选定CPU（越高越好）
- 设定年代大小、升级年龄
- 设定日志参数
- -Xloggc:/opt/xxx/logs/xxx-xxx-gc-%t.log -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=5 -XX:GCLogFileSize=20M -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCCause
- 或者每天产生一个日志文件
- 观察日志情况
- 熟悉业务场景（没有最好的垃圾回收器，只有最合适的垃圾回收器）
top命令 查看进程占用资源情况
-
Processes: 393 total, 2 running, 391 sleeping, 1727 threads 10:26:14
-
Load
Avg:
3.60,
3.03,
2.80 CPU
usage:
21.24%
user,
14.8%
sys,
64.67% idle SharedLibs:
217M resident,
60M
data,
39M linkedit.
-
MemRegions:
111000 total,
5331M resident,
158M
private,
1972M shared. PhysMem:
16G used (
2420M wired),
480M unused.
-
VM:
2005G vsize,
1297M framework vsize,
725056(
0) swapins,
845477(
0) swapouts. Networks: packets:
7278266/
11G
in,
5756934/
4837M out.
-
Disks:
1039370/
15G
read,
2239416/
30G written.
-
-
PID COMMAND %CPU
TIME #TH #WQ #PORT MEM PURG CMPRS PGRP PPID STATE BOOSTS %CPU_ME %CPU_OTHRS UID
-
6738 top
3.9
00:
00.70
1/
1
0
25
4880K+
0B
0B
6738
4188 running *
0[
1]
0.00000
0.00000
0
-
6736 CFNetworkAge
0.0
00:
00.10
3
2
43
10M
0B
0B
6736
1 sleeping *
0[
1]
0.00000
0.00000
0
-
6734 ocspd
0.0
00:
00.02
2
1
31
1636K
0B
0B
6734
1 sleeping *
0[
1]
0.00000
0.00000
0
-
6731 backupd
0.0
00:
00.04
2
1
42
1612K
0B
0B
6731
1 sleeping *
0[
1]
0.00000
0.00000
0
-
6730 VTDecoderXPC
0.0
00:
00.55
2
1
50
5288K
0B
0B
6730
1 sleeping
0[
43]
0.00000
0.00000
501
-
6710 CoreServices
0.0
00:
00.20
3
1
164
4288K
0B
0B
6710
1 sleeping *
0[
1]
0.00000
0.00000
501
-
6708 Google Chrom
0.0
00:
00.14
12
1
100
14M
4096B
0B
737
737 sleeping *
0[
7]
0.00000
0.00000
501
-
6707 Google Chrom
0.0
00:
00.52
12
1
142
25M
4096B
0B
737
737 sleeping *
0[
5]
0.00000
0.00000
501
-
6705 Google Chrom
0.0
00:
00.37
12
1
134
18M
4096B
0B
737
737 sleeping *
0[
6]
0.00000
0.00000
501
-
6703 Google Chrom
0.0
00:
04.29
13
1
155
72M
4096B
0B
737
737 sleeping *
0[
5]
0.00000
0.00000
501
jps 命令 查看 java进程
-
MacBook-
Pro:~ sysadmin$ jps
-
6613 Launcher
-
6605
-
6733 Jps
-
jstack 命令 关注 WATTING 查看死锁问题
-
MacBook-Pro:~ sysadmin$ jstack
6613
-
2020-
02-
10
10:
24:
35
-
Full thread
dump Java HotSpot(TM)
64-Bit Server VM (
25.161-b12 mixed mode):
-
-
"Attach Listener"
#13 daemon prio=9 os_prio=31 tid=0x00007fb2d1869000 nid=0xb07 waiting on condition [0x0000000000000000]
-
java.lang.Thread.State: RUNNABLE
-
-
"DestroyJavaVM"
#12 prio=5 os_prio=31 tid=0x00007fb2cf2ea000 nid=0x2703 waiting on condition [0x0000000000000000]
-
java.lang.Thread.State: RUNNABLE
-
-
"JPS event loop"
#9 prio=5 os_prio=31 tid=0x00007fb2d01de000 nid=0x4703 runnable [0x000070000bc6e000]
-
java.lang.Thread.State: RUNNABLE
-
at sun.nio.ch.KQueueArrayWrapper.kevent
0(Native Method)
-
at sun.nio.ch.KQueueArrayWrapper.poll(KQueueArrayWrapper.java:
198)
-
at sun.nio.ch.KQueueSelectorImpl.doSelect(KQueueSelectorImpl.java:
117)
-
at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:
86)
-
- locked <
0x00000007b57
jstat -gc pid 查看 GC 情况
-
MacBook-
Pro:~ sysadmin$ jstat -gc
6613
-
S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT GCT
-
10752.0
10752.0
0.
0
4405.1
65536.0
26391.4
175104.0
152.0
17152.0
16563.7
2048.0
1933.2
1
0.
007
0
0.
000
0.
007
jinfo pid 查看 jvm 常用信息
-
-
[root@henghe-
023 sbin]# jinfo
27519
-
Attaching
to process ID
27519, please wait...
-
Debugger attached successfully.
-
Server compiler detected.
-
JVM version
is
25.151-b12
-
Java System Properties:
-
-
java.runtime.
name = Java(TM) SE Runtime Environment
-
java.vm.version =
25.151-b12
-
sun.boot.
library.path = /opt/jdk1.
8/jre/lib/amd64
-
hadoop.root.logger = INFO,RFA
-
java.vendor.url = http:
//java.oracle.com/
-
java.vm.vendor = Oracle Corporation
-
path.separator = :
-
file.encoding.pkg = sun.io
-
java.vm.
name = Java HotSpot(TM)
64-Bit Server VM
-
sun.os.patch.level = unknown
-
sun.java.launcher = SUN_STANDARD
-
user.country = CN
-
user.dir = /opt/hadoop-
2.7.
4
-
java.vm.specification.
name = Java
Virtual Machine Specification
-
hdfs.audit.logger = INFO,NullAppender
-
java.runtime.version =
1.8.
0_151-b12
-
java.awt.graphicsenv = sun.awt.X11GraphicsEnvironment
-
os.arch = amd64
-
java.endorsed.dirs = /opt/jdk1.
8/jre/lib/endorsed
-
line.separator =
-
-
java.io.tmpdir = /tmp
-
hadoop.log.
file = hadoop-root-namenode-henghe-
023.log
-
java.vm.specification.vendor = Oracle Corporation
-
os.
name = Linux
-
hadoop.id.str = root
-
sun.jnu.encoding = UTF-
8
-
java.
library.path = /usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
-
hadoop.home.dir = /opt/hadoop-
2.7.
4
-
java.specification.
name = Java
Platform API Specification
-
java.
class.version =
52.0
-
java.net.preferIPv4Stack = true
-
proc_namenode =
-
sun.management.compiler = HotSpot
64-Bit Tiered Compilers
-
os.version =
3.10.
0-
1062.4.
3.el7.x86_64
-
user.home = /root
-
user.timezone = Asia/Shanghai
-
java.awt.printerjob = sun.print.PSPrinterJob
-
file.encoding = UTF-
8
-
java.specification.version =
1.8
-
user.
name = root
-
java.
class.path = /opt/hadoop-
2.7.
4/etc/hadoop:************.jar
-
java.vm.specification.version =
1.8
-
sun.arch.data.model =
64
-
sun.java.command = org.apache.hadoop.hdfs.server.namenode.NameNode
-
java.home = /opt/jdk1.
8/jre
-
user.language = zh
-
java.specification.vendor = Oracle Corporation
-
hadoop.security.logger = INFO,RFAS
-
awt.toolkit = sun.awt.X11.XToolkit
-
java.vm.info = mixed mode
-
hadoop.log.dir = /opt/hadoop-
2.7.
4/logs
-
java.version =
1.8.
0_151
-
java.ext.dirs = /opt/jdk1.
8/jre/lib/ext:/usr/java/packages/lib/ext
-
sun.boot.
class.path = /opt/jdk1.
8/jre/lib/resources.jar:/opt/jdk1.
8/jre/lib/rt.jar:/opt/jdk1.
8/jre/lib/sunrsasign.jar:/opt/jdk1.
8/jre/lib/jsse.jar:/opt/jdk1.
8/jre/lib/jce.jar:/opt/jdk1.
8/jre/lib/charsets.jar:/opt/jdk1.
8/jre/lib/jfr.jar:/opt/jdk1.
8/jre/classes
-
java.vendor = Oracle Corporation
-
file.separator = /
-
java.vendor.url.bug = http:
//bugreport.sun.com/bugreport/
-
sun.io.unicode.encoding = UnicodeLittle
-
sun.cpu.endian = little
-
hadoop.policy.
file = hadoop-policy.xml
-
sun.cpu.isalist =
-
-
VM Flags:
-
Non-
default VM flags: -XX:CICompilerCount=
3 -XX:InitialHeapSize=
9995026432 -XX:MaxHeapSize=
9995026432 -XX:MaxNewSize=
1073741824 -XX:MinHeapDeltaBytes=
524288 -XX:NewSize=
1073741824 -XX:OldSize=
8921284608 -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseFastUnorderedTimeStamps -XX:+UseParallelGC
-
Command line: -Dproc_namenode -Xmx1000m -Djava.net.preferIPv4Stack=true -Dhadoop.log.dir=/opt/hadoop-
2.7.
4/logs -Dhadoop.log.
file=hadoop.log -Dhadoop.home.dir=/opt/hadoop-
2.7.
4 -Dhadoop.id.str=root -Dhadoop.root.logger=INFO,console -Dhadoop.policy.
file=hadoop-policy.xml -Djava.net.preferIPv4Stack=true -Djava.net.preferIPv4Stack=true -Djava.net.preferIPv4Stack=true -Dhadoop.log.dir=/opt/hadoop-
2.7.
4/logs -Dhadoop.log.
file=hadoop-root-namenode-henghe-
023.log -Dhadoop.home.dir=/opt/hadoop-
2.7.
4 -Dhadoop.id.str=root -Dhadoop.root.logger=INFO,RFA -Dhadoop.policy.
file=hadoop-policy.xml -Djava.net.preferIPv4Stack=true -Xmx9531m -Xms9531m -Xmn1024m -Dhadoop.security.logger=INFO,RFAS -Dhdfs.audit.logger=INFO,NullAppender -Xmx9531m -Xms9531m -Xmn1024m -Dhadoop.security.logger=INFO,RFAS -Dhdfs.audit.logger=INFO,NullAppender -Xmx9531m -Xms9531m -Xmn1024m -Dhadoop.security.logger=INFO,RFAS -Dhdfs.audit.logger=INFO,NullAppender -Dhadoop.security.logger=INFO,RFAS
arthas [推荐]
Arthas 是Alibaba开源的Java诊断工具.
安装&启动
-
curl -O https:
//alibaba.github.io/arthas/arthas-boot.jar
-
java -jar arthas-boot.jar
-
[root@henghe
-023 data]
# java -jar arthas-boot.jar
-
[INFO] arthas-boot version:
3.1
.7
-
[INFO] Found existing java process, please choose one
and hit
RETURN.
-
* [
1]:
28443 org.apache.hadoop.hdfs.server.datanode.DataNode
-
[
2]:
27519 org.apache.hadoop.hdfs.server.namenode.NameNode
-
2
-
[INFO] arthas home: /root/.arthas/lib/
3.1
.7/arthas
-
[INFO]
Try to attach process
27519
-
[INFO] Attach process
27519 success.
-
[INFO] arthas-client connect
127.0
.0
.1
3658
-
,---. ,------. ,--------.,--. ,--. ,---. ,---.
-
/ O \ | .--.
''--. .--
'| '--
' | / O \ ' .-
'
-
| .-. || '--
'.' | | | .--. || .-. |`. `-.
-
| | | || |\ \ | | | | | || | | |.-
' |
-
`--' `--
'`--'
'--' `--
' `--' `--
'`--' `--
'`-----'
-
-
-
wiki https:
//alibaba.github.io/arthas
-
tutorials https:
//alibaba.github.io/arthas/arthas-tutorials
-
version
3.1
.7
-
pid
28443
-
time
2020
-02
-10
10:
46:
37
-
-
[arthas@
28443]$
安装/使用参考官方文档: https://alibaba.github.io/arthas/install-detail.html
-
[arthas@
14804]$ dashboard
-
ID NAME GROUP PRIORITY STATE %CPU
TIME INTERRUPT DAEMON
-
20 pool
-1-thread
-12 main
5 WAITING
4
0:
0
false
false
-
27 pool
-1-thread
-19 main
5 WAITING
4
0:
0
false
false
-
10 pool
-1-thread
-2 main
5 WAITING
3
0:
0
false
false
-
50 pool
-1-thread
-42 main
5 WAITING
3
0:
0
false
false
-
19 pool
-1-thread
-11 main
5 WAITING
2
0:
0
false
false
-
22 pool
-1-thread
-14 main
5 WAITING
2
0:
0
false
false
-
24 pool
-1-thread
-16 main
5 WAITING
2
0:
0
false
false
-
25 pool
-1-thread
-17 main
5 WAITING
2
0:
0
false
false
-
28 pool
-1-thread
-20 main
5 WAITING
2
0:
0
false
false
-
33 pool
-1-thread
-25 main
5 WAITING
2
0:
0
false
false
-
39 pool
-1-thread
-31 main
5 WAITING
2
0:
0
false
false
-
41 pool
-1-thread
-33 main
5 WAITING
2
0:
0
false
false
-
44 pool
-1-thread
-36 main
5 WAITING
2
0:
0
false
false
-
45 pool
-1-thread
-37 main
5 WAITING
2
0:
0
false
false
-
54 pool
-1-thread
-46 main
5 WAITING
2
0:
0
false
false
-
57 pool
-1-thread
-49 main
5 WAITING
2
0:
0
false
false
-
13 pool
-1-thread
-5 main
5 WAITING
2
0:
0
false
false
-
58 pool
-1-thread
-50 main
5 WAITING
2
0:
0
false
false
-
Memory used total max usage GC
-
heap
63M
89M
89M
71.18% gc.ps_scavenge.count
17
-
ps_eden_space
5M
11M
11M
51.41% gc.ps_scavenge.
time(ms)
232
-
ps_survivor_space
3M
11M
11M
28.69% gc.ps_marksweep.count
0
-
ps_old_gen
54M
67M
67M
81.52% gc.ps_marksweep.
time(ms)
0
-
nonheap
19M
20M
-1
95.94%
-
code_cache
4M
4M
240M
1.79%
-
metaspace
13M
14M
-1
97.40%
-
compressed_class_space
1M
1M
1024M
0.16%
-
-
Runtime
-
os.name Linux
-
os.version
3.10
.0
-1062.4
.3.el7.x86_64
-
java.version
1.8
.0_151
-
java.home /opt/jdk1
.8/jre
-
systemload.average
0.60
-
processors
6
-
uptime
182s
-
-
-
ID NAME GROUP PRIORITY STATE %CPU
TIME INTERRUPT DAEMON
-
57 pool
-1-thread
-49 main
5 WAITING
8
0:
0
false
false
-
10 pool
-1-thread
-2 main
5 WAITING
5
0:
0
false
false
-
22 pool
-1-thread
-14 main
5 TIMED_WAI
3
0:
0
false
false
-
45 pool
-1-thread
-37 main
5 WAITING
2
0:
0
false
false
-
54 pool
-1-thread
-46 main
5 WAITING
2
0:
0
false
false
-
16 pool
-1-thread
-8 main
5 WAITING
2
0:
0
false
false
-
73
Timer-
for-arthas-dashboard
-6 system
10 RUNNABLE
1
0:
0
false
true
-
9 pool
-1-thread
-1 main
5 WAITING
1
0:
0
false
false
-
18 pool
-1-thread
-10 main
5 WAITING
1
0:
0
false
false
-
19 pool
-1-thread
-11 main
5 WAITING
1
0:
0
false
false
-
20 pool
-1-thread
-12 main
5 WAITING
1
0:
0
false
false
-
21 pool
-1-thread
-13 main
5 WAITING
1
0:
0
false
false
-
23 pool
-1-thread
-15 main
5 WAITING
1
0:
0
false
false
-
24 pool
-1-thread
-16 main
5 WAITING
1
0:
0
false
false
-
25 pool
-1-thread
-17 main
5 WAITING
1
0:
0
false
false
-
26 pool
-1-thread
-18 main
5 WAITING
1
0:
0
false
false
-
27 pool
-1-thread
-19 main
5 WAITING
1
0:
0
false
false
-
28 pool
-1-thread
-20 main
5 WAITING
1
0:
0
false
false
-
Memory used total max usage GC
-
heap
68M
89M
89M
76.85% gc.ps_scavenge.count
17
-
ps_eden_space
10M
11M
11M
96.60% gc.ps_scavenge.
time(ms)
232
-
ps_survivor_space
3M
11M
11M
28.69% gc.ps_marksweep.count
0
-
ps_old_gen
54M
67M
67M
81.52% gc.ps_marksweep.
time(ms)
0
-
nonheap
20M
21M
-1
95.65%
-
code_cache
4M
4M
240M
1.87%
-
metaspace
13M
14M
-1
95.72%
-
compressed_class_space
1M
1M
1024M
0.17%
-
-
Runtime
-
os.name Linux
-
os.version
3.10
.0
-1062.4
.3.el7.x86_64
-
java.version
1.8
.0_151
-
java.home /opt/jdk1
.8/jre
-
systemload.average
0.55
-
processors
6
-
uptime
187s
使用 jmap 命令 [生产环境慎用! 会造成生产环境卡顿!!!!]
jmap -histo $PID | head -50 查看类对象
示例:
-
-
[root@henghe-
023 arthas]
# jmap -histo 23893 | head -50
-
-
num
#instances #bytes class name
-
----------------------------------------------
-
1:
381601
27475272 java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask
-
2:
506262
16200384 java.util.concurrent.locks.AbstractQueuedSynchronizer$Node
-
3:
381626
15265040 java.math.BigDecimal
-
4:
381600
12211200 com.zl.gc.T15_FullGC_Problem01$CardInfo
-
5:
381612
9158688 java.util.Date
-
6:
381602
9158448 java.util.concurrent.Executors$RunnableAdapter
-
7:
381600
6105600 com.zl.gc.T15_FullGC_Problem01$$Lambda$2/
245257410
-
8:
131012
4192384 java.util.HashMap$Node
-
9:
2470
4135208 [B
-
10:
36531
2892152 [Ljava.lang.Object;
-
11:
3
2662808 [Ljava.util.concurrent.RunnableScheduledFuture;
-
12:
53790
2048256 [C
-
13:
14342
1669984 [I
-
14:
53552
1285248 java.lang.String
-
15:
2355
1134592 [Ljava.util.HashMap$Node;
-
16:
33494
803856 java.util.ArrayList
-
17:
31471
755304 io.termd.core.term.Feature
-
18:
30539
488624 io.termd.core.term.OpCode$Literal
-
19:
26476
423616 io.termd.core.term.Sequence
-
20:
2710
306568 java.lang.Class
-
21:
5178
207120 java.util.LinkedHashMap$Entry
-
22:
1575
138600 java.lang.reflect.Method
-
23:
156
102336 io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueue
-
24:
28
98816 [Ljava.nio.channels.SelectionKey;
-
25:
1887
90576 java.util.HashMap
-
26:
2700
86400 com.taobao.text.Style$Composite
-
27:
2647
84704 io.termd.core.term.OpCode$Printf
-
28:
4643
74288 io.termd.core.term.OpCode$PushParam
-
29:
1629
52128 io.termd.core.term.Device
-
30:
1795
43064 [Ljava.lang.Class;
-
31:
1314
42048 io.termd.core.term.Capability
-
32:
443
40336 [Ljava.lang.String;
-
33:
1169
37408 io.termd.core.term.TermInfoBuilder$Entry
-
34:
645
36120 java.util.LinkedHashMap
-
35:
475
34200 java.lang.reflect.Field
-
36:
1397
33528 io.termd.core.term.OpCode$PushConstant
-
37:
1327
31848 io.termd.core.term.OpCode$If
-
38:
1327
31848 io.termd.core.term.OpCode$Then
-
39:
492
27552 java.util.zip.ZipFile$ZipFileInflaterInputStream
-
40:
492
27552 java.util.zip.ZipFile$ZipFileInputStream
-
41:
48
27264 io.netty.util.internal.shaded.org.jctools.queues.MpscUnboundedArrayQueue
-
42:
667
26680 java.util.ArrayList$SubList
-
43:
819
26208 java.util.concurrent.ConcurrentHashMap$Node
-
44:
612
24480 java.lang.ref.Finalizer
-
45:
59
22184 java.lang.Thread
-
46:
10
17120 [Lio.netty.buffer.PoolSubpage;
-
47:
383
15320 java.lang.ref.SoftReference
-
[root@henghe-
023 arthas]
#
jmap -dump:format=b,file=20200210.hprof $PID 将内存信息生成文件,进行分析 [jhat, jvisualvm,mat]
-
[root@henghe-
023 arthas]# jmap -dump:format=b,
file=
20200210.hprof
23893
-
Dumping heap
to /data/arthas/
20200210.hprof ...
-
Heap dump
file created
使用jvisualvm 进行查看 dump 文件[试验用]
/Library/java/JavaVirtualMachines/jdk1.8.0_161.jdk/Contents/Home/bin/jvisualvm
JVM 日志设置
-Xloggc:/opt/xxx/logs/xxx-xxx-gc-%t.log -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=5 -XX:GCLogFileSize=20M -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCCause
-
-Xloggc:
/opt/xxx/logs/xxx-gc-%t.log
// GC 文件路径
-
-XX:+UseGCLogFileRotation
// 启用 GC日志滚动记录功能
-
-XX:NumberOfGCLogFiles=
5
// 生成 GC 文件数量
-
-XX:GCLogFileSize=
20M
// 单个 GC 文件大小
-
-XX:+PrintGCDetails
// 打印 GC 详情
-
-XX:+PrintGCDateStamps
// 打印 GC 时间戳
-
-XX:+PrintGCCause
// 打印 GC 产生原因
-
对象创建流程
CMS GC 过程
初始标记和重新标记要 触发 STW
转载：https://blog.csdn.net/zhanglong_4444/article/details/104242276
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