blocks|key|2856098|text|您可以在外部使用jstat查看这些大小，如|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2856099|jstat+-gc+{pid}+10s|code-block|syntax|javascript|2856100|您可以通过|2856101|jps+-lvm|2856102|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

You can watch these sizes externally using jstat like

<pre><code>jstat -gc {pid} 10s
</code></pre>

You can find out the pid by using

<pre><code>jps -lvm
</code></pre>

blocks|key|466418|text|Perm生成是通过MaxPermSize分配的单独空间。这不包括在-Xmx中|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|466419|-Xmx包括一个伊甸园空间，两个幸存者空间和老一代。|466420|您甚至可以通过了解--xx:NewRation:来计算各个空间。这是年轻一代和老年人之间的比例。例如，如果one+forth是3，则比率是1:3，而Eden和survivor空间的组合大小是年轻一代和老年一代总规模的3。|BOLD|466421|您还可以使用jstat命令来了解单个的大小，并且像VisualVM这样的工具也可以对您有很大的帮助。只需看一看图片，它说明您的个人空间细节的图形表示。|466422|​|466423|📷|atomic|466424|466425|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://developer.qcloudimg.com/http-save/yehe-900000/60a48e4485fa7c73eeb02011326482c6.png|imageAlt^0|9|B|X|4|0|0|4|0|9|F|1H|9|1R|1|1X|3|22|4|27|8|30|1|1H|9|0|6|5|P|8|6|5|0|0|0|1|0|0|0^^$0|@$1|2|3|4|5|6|7|11|8|@$9|12|A|13|B|C]|$9|14|A|15|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|16|8|@$9|17|A|18|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|19|8|@$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]|$9|1E|A|1F|B|C]|$9|1G|A|1H|B|C]|$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]|$9|1M|A|1N|B|C]|$9|1O|A|1P|B|J]]|D|@]|E|$]]|$1|K|3|L|5|6|7|1Q|8|@$9|1R|A|1S|B|J]|$9|1T|A|1U|B|J]|$9|1V|A|1W|B|C]]|D|@]|E|$]]|$1|M|3|N|5|6|7|1X|8|@]|D|@]|E|$]]|$1|O|3|P|5|Q|7|1Y|8|@]|D|@$9|1Z|A|20|1|21]]|E|$]]|$1|R|3|N|5|6|7|22|8|@]|D|@]|E|$]]|$1|S|3|-4|5|6|7|23|8|@]|D|@]|E|$]]]|T|$U|$5|V|W|X|E|$Y|Z|10|-4]]]]

Perm generation is a separate space allocated via <code>MaxPermSize</code>. This is not included in <code>-Xmx</code>

<code>-Xmx</code> includes one Eden space , two survivor space and old generation.

You can even calculate the individual spaces by knowing <code>--xx:NewRation:</code>. This is ratio between the young and old generations. For example if <code>n</code> is <code>3</code> than ratio is <code>1:3</code> and the combined size of <code>Eden</code> and <code>survivor</code> spaces is <code>one forth</code> of the total size of the young and old generation.

You can also use <code>jstat</code> command to know individual sizes and also tools like VisualVM can help you great deal. Just look in to the picture which states you pictorial representation of individual space details.

<img src="https://i.stack.imgur.com/aphc1.png" alt="enter image description here">

blocks|key|1777885|text|如果您想知道这些空间的大小，请使用java选项-verbose:gc+-XX:%2BPrintGCDetails。这个文档将帮助您理解不同世代的工作方式。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1777886|entityMap|0|LINK|mutability|MUTABLE|url|http://www.oracle.com/technetwork/java/javase/gc-tuning-6-140523.html^0|N|V|1L|2|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]]|D|@$9|Q|A|R|1|S]]|E|$]]|$1|F|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

If you want to know the size of those space use the java option <code>-verbose:gc -XX:+PrintGCDetails</code>.
This <a href="http://www.oracle.com/technetwork/java/javase/gc-tuning-6-140523.html" rel="nofollow">documentation</a> will help you understand how the differents generations work.

blocks|key|467936|text|通过-Xmx分配的最大堆大小是年轻一代和终身代的组合。permgen空间是单独分配的，使用-XX:MaxPermSize选项对JVM进行分配。以下是这个问题的答案：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|467937|permgen是否包括在-Xmx中？|467938|在JVM中(尤其是在远程服务器上)，确定堆中不同代的大小大小的一个好方法是使用jmap命令：|467939|http://docs.oracle.com/javase/6/docs/technotes/tools/share/jmap.html|467940|下面是我管理的服务器的一些示例输出：|467941|$+sudo+jmap+-heap+28579

Attaching+to+process+ID+28579,+please+wait...
Debugger+attached+successfully.
Server+compiler+detected.
JVM+version+is+1.5.0_07-b03

using+parallel+threads+in+the+new+generation.
using+thread-local+object+allocation.
Concurrent+Mark-Sweep+GC

Heap+Configuration:
+++MinHeapFreeRatio+=+40
+++MaxHeapFreeRatio+=+70
+++MaxHeapSize++++++=+6127878144+(5844.0MB)
+++NewSize++++++++++=+2147483648+(2048.0MB)
+++MaxNewSize+++++++=+2147483648+(2048.0MB)
+++OldSize++++++++++=+3980394496+(3796.0MB)
+++NewRatio+++++++++=+15
+++SurvivorRatio++++=+1024
+++PermSize+++++++++=+314572800+(300.0MB)
+++MaxPermSize++++++=+314572800+(300.0MB)

Heap+Usage:
New+Generation+(Eden+%2B+1+Survivor+Space):
+++capacity+=+2145452032+(2046.0625MB)
+++used+++++=+2130014864+(2031.3404693603516MB)
+++free+++++=+15437168+(14.722030639648438MB)
+++99.28047014010332%25+used
Eden+Space:
+++capacity+=+2143420416+(2044.125MB)
+++used+++++=+2130014864+(2031.3404693603516MB)
+++free+++++=+13405552+(12.784530639648438MB)
+++99.37457197384462%25+used
From+Space:
+++capacity+=+2031616+(1.9375MB)
+++used+++++=+0+(0.0MB)
+++free+++++=+2031616+(1.9375MB)
+++0.0%25+used
To+Space:
+++capacity+=+2031616+(1.9375MB)
+++used+++++=+0+(0.0MB)
+++free+++++=+2031616+(1.9375MB)
+++0.0%25+used
concurrent+mark-sweep+generation:
+++capacity+=+3980394496+(3796.0MB)|code-block|syntax|javascript|467942|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/4084280/is-permgen-included-in-xmx|1^0|2|4|19|F|0|0|I|0|0|0|0|1W|1|0|0|0^^$0|@$1|2|3|4|5|6|7|11|8|@$9|12|A|13|B|C]|$9|14|A|15|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|16|8|@]|D|@$9|17|A|18|1|19]]|E|$]]|$1|H|3|I|5|6|7|1A|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|1B|8|@]|D|@$9|1C|A|1D|1|1E]]|E|$]]|$1|L|3|M|5|6|7|1F|8|@]|D|@]|E|$]]|$1|N|3|O|5|P|7|1G|8|@]|D|@]|E|$Q|R]]|$1|S|3|-4|5|6|7|1H|8|@]|D|@]|E|$]]]|T|$U|$5|V|W|X|E|$Y|Z]]|10|$5|V|W|X|E|$Y|K]]]]

The max heap size allocated via <code>-Xmx</code> is a combination of the young generation and the tenured generation. permgen space is allocated separately, using the <code>-XX:MaxPermSize</code> option to the JVM. This question is answered here:

<a href="https://stackoverflow.com/questions/4084280/is-permgen-included-in-xmx">Is permgen included in -Xmx?</a>

One good way to determine the sizing of the different generations in the heap in a JVM - particularly on a remote server - is to use the jmap command:

<a href="http://docs.oracle.com/javase/6/docs/technotes/tools/share/jmap.html" rel="nofollow noreferrer">http://docs.oracle.com/javase/6/docs/technotes/tools/share/jmap.html</a>

Here's some sample output from a server that I administer:

<pre><code>$ sudo jmap -heap 28579

Attaching to process ID 28579, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 1.5.0_07-b03

using parallel threads in the new generation.
using thread-local object allocation.
Concurrent Mark-Sweep GC

Heap Configuration:
 MinHeapFreeRatio = 40
 MaxHeapFreeRatio = 70
 MaxHeapSize = 6127878144 (5844.0MB)
 NewSize = 2147483648 (2048.0MB)
 MaxNewSize = 2147483648 (2048.0MB)
 OldSize = 3980394496 (3796.0MB)
 NewRatio = 15
 SurvivorRatio = 1024
 PermSize = 314572800 (300.0MB)
 MaxPermSize = 314572800 (300.0MB)

Heap Usage:
New Generation (Eden + 1 Survivor Space):
 capacity = 2145452032 (2046.0625MB)
 used = 2130014864 (2031.3404693603516MB)
 free = 15437168 (14.722030639648438MB)
 99.28047014010332% used
Eden Space:
 capacity = 2143420416 (2044.125MB)
 used = 2130014864 (2031.3404693603516MB)
 free = 13405552 (12.784530639648438MB)
 99.37457197384462% used
From Space:
 capacity = 2031616 (1.9375MB)
 used = 0 (0.0MB)
 free = 2031616 (1.9375MB)
 0.0% used
To Space:
 capacity = 2031616 (1.9375MB)
 used = 0 (0.0MB)
 free = 2031616 (1.9375MB)
 0.0% used
concurrent mark-sweep generation:
 capacity = 3980394496 (3796.0MB)
</code></pre>

a) As I know <code>-Xmx</code> represents max heap. 
Is it a combination of young generation(eden+survivor) and tenured generation(old generation) and perm gen ?

b) How can I now the min/max size of different spaces of memory of the application which is in UAT/Prod
1) eden space 
2) survior space 
3) tenured 
4) perm gen

Java heap Xmx flag and max size of diff spaces of my app in prod

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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如我所知，-Xmx代表最大堆。它是年轻一代(eden+survivor)和终身世代(老一代)和烫发一代的结合吗？( b)我现在如何才能在UAT/Prod 1)伊甸园空间中计算出应用程序不同内存空间的最小/最大尺寸2)生存空间3)终身4)烫发原

问Java堆Xmx标志和我的应用程序在prod中的diff空间的最大大小
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