Hi
I would like to know what are the default JVM arguments when server jvm is started without any additional flags, like this:
java -server myapp
I have been unable to find bullet proof document from those. I'm running Sun 1.5.0_08 on 32bit Win2003.
I would espacially be interested on thread stack size, useTLAB?, xmx & xms...
Br
Draes
> I would espacially be interested in;
> thread stack size,
On Win - default is in the binary file - use EDITBIN to manipulate - needed to change primorial thread - other threads use -Xss
> useTLAB?,
true for both client & server - on all platforms - for JVM after 1.3
> xmx &
The default size is 32M for clients and 64M for servers.
> xms...
Who cares.
http://java.sun.com/javase/technologies/hotspot/vmoptions.jsp
> Thanks tschodt
>
> Is there any limit how small xss parameter can be in
> java 5. Some pages say that in java 6 it is 64kb, is
> it same in java 5?
>
> Br
>Draes
Not sure what the limit is on this, but according to this site:
http://www.caucho.com/resin-3.0/performance/jvm-tuning.xtp
If the stack space is too small, eventually you will see an exception class java.lang.StackOverflowError .
> > xmx &
>
> The default size is 32M for clients and 64M for
> servers.
The default was 64M for both client and server, but starting with JDK 1.5, it's more complicated than that. The parallel collector (option -XX:+UseParallelGC) uses a fraction of the installed physical memory as the default maximum heap size (-Xmx). Note that the parallel collector is also selected by default on some platforms; see
http://java.sun.com/j2se/1.5.0/docs/guide/vm/gc-ergonomics.html
Note that the above also applies to Java SE 6.
> > > xmx &
> >
> > The default size is 32M for clients and 64M for
> > servers.
>
> The default was 64M for both client and server, but
> starting with JDK 1.5, it's more complicated than
> that.
Ah, yes - it is the defaults for MaxPermSize that are 32m for client and 64m for server.
> Ah, yes - it is the defaults for MaxPermSize
> that are 32m for client and 64m for server.
The default MaxPermSize is 64m for both client and server, at least in 1.4 and later releases. However, starting with 1.5, the default value for PermSize, which is the initial size of the permanent generation, is different: server is 16m, client is 8m in 1.5 and 12m in 1.6.
> > Ah, yes - it is the defaults for
> MaxPermSize
> > that are 32m for client and 64m for server.
>
> The default MaxPermSize is 64m for both client and
> server, at least in 1.4 and later releases.
> However, starting with 1.5, the default value for
> PermSize, which is the initial size of the
> permanent generation, is different: server is 16m,
> client is 8m in 1.5 and 12m in 1.6.
Already from 1.4.2: http://java.sun.com/docs/hotspot/gc1.4.2/faq.html (FAQ #30)
I do find it strange that I can find no mention of these changes in the release notes;
http://java.sun.com/products/archive/j2se/1.4.0_04/ReleaseNotes.html
http://java.sun.com/products/archive/j2se/1.4.1_07/ReleaseNotes.html
