Multiple Platforms

[Rick Rothweiler]

Hi All:
I am fairley new to java,  and receintly wrote a very
simple program  in a windows IDE.  I tried to run the .class file on my

linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
machine says "Exception in thread "main"

java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.


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Re: Multiple Platforms

[Ingo Rockel]

On -1 xxx -1, Rick Rothweiler wrote:

> Hi All:
> I am fairley new to java,  and receintly wrote a very
> simple program  in a windows IDE.  I tried to run the .class file on my
> 
> linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
> machine says "Exception in thread "main"
> 
> java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.
The VM did not find the Class, you have to set the CLASSPATH var (e.g 
export CLASSPATH=$CLASSPATH:/where/are/my/classes
with bash)

Then you could start ypur class First.class with: java First
>
This is a problem with your java setup not with any incompabilities
between linux and windows. Under Windows the IDE you installed has setup
the classpath.

Ingo 

* **
**  In the manual it said "For use with W95, W98 or better"*
*** So I installed Linux... 
 ***
*   Ingo Rockel, EMAIL: [EMAIL PROTECTED] **
**   Homepage: http://inro.da.ru   *


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Re: Multiple Platforms

[John Rousseau]

On Friday May 12, 2000, Rick Rothweiler wrote:

> Hi All:
> I am fairley new to java,  and receintly wrote a very
> simple program  in a windows IDE.  I tried to run the .class file on my
> 
> linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
> machine says "Exception in thread "main"
> 
> java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.

You need to run the command "java First_tst", _not_ "java
First_txt.class".

-John


John Rousseau   [EMAIL PROTECTED]
SilverStream Software Phone: +1 781 238 5564
1 Burlington Woods  Fax: +1 781 238 5499
Burlington, MA 01803 http://www.silverstream.com



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RE: IBM has posted early-access JDK 1.3

[Gayathri Viswanathan]

Hi !

Is the setRequestProperty method in java.net.URLConnection implemented in
this version ? I checked out the Sun release for Windows and the 1.3 version
doesnt seem to have implemented it yet.

Thanks a lot.

--Gayathri


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Re: Multiple Platforms

[Kristian Soerensen]

Hi

Call it like this:
java First_tst

and it schould work.
Read up on Classpath and package conventions to get the whole idea of
what's going on here.

---   http://www.elof.dk   --
Kristian Elof Soerensen  [EMAIL PROTECTED]   (+45) 45 93 92 02 

On Fri, 12 May 2000, Rick Rothweiler wrote:

> Hi All:
> I am fairley new to java,  and receintly wrote a very
> simple program  in a windows IDE.  I tried to run the .class file on my
> 
> linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
> machine says "Exception in thread "main"
> 
> java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.
> 
> 
> --
> To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
> 
> 


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Re: Multiple Platforms

[David Marshall]

Rick Rothweiler wrote:

> Hi All:
> I am fairley new to java,  and receintly wrote a very
> simple program  in a windows IDE.  I tried to run the .class file on my
>
> linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
> machine says "Exception in thread "main"
>
> java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.

Rick,

Leave off the '.class' extension when invoking from the command line. I.e.
invoke as:

java First_tst

not as:java First_tst.class

See the JDK1.2.2 docs for additional details. You won't find Linux
specific docs in the core docs, but just follow the Solaris thread for
command line tools, environment etc as the same options would apply to the
corresponding Linux versions.

--
David Marshall   mailto:[EMAIL PROTECTED]
VM Systems, Inc.   http://www.vmguys.com




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Re: Multiple Platforms

[Matthias Pfisterer]

Hi Rick,

Do not run your program with
java First_tst.class
Instead, run it with
java First_tst

Matthias


Rick Rothweiler wrote:
> 
> Hi All:
> I am fairley new to java,  and receintly wrote a very
> simple program  in a windows IDE.  I tried to run the .class file on my
> 
> linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
> machine says "Exception in thread "main"
> 
> java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.
> 
> --
> To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]

-- 
Matthias Pfisterer  

Share your knowledge.
It's a way to achieve immortality.

 (from a nepalese mantra)

Java Sound Examples:
http://rupert.informatik.uni-stuttgart.de/~pfistere/jsexamples/
Tritonus, the open source implementation of the Java Sound API:
http://tritonus.sourceforge.net/
--


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RE: IBM has posted early-access JDK 1.3

[Paul Ho]

AFAICT implemention for setRequestProperty is the same in jdk 1.1, 1.2 and 1.3
Don't forget java.net.URLConnection is an abstract class.

Cheers,
Paul

At 11:53 AM -0400 5/9/0, Gayathri Viswanathan wrote:
>Hi !
>
>Is the setRequestProperty method in java.net.URLConnection implemented in
>this version ? I checked out the Sun release for Windows and the 1.3 version
>doesnt seem to have implemented it yet.



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Re: jdk1.1.7 v1a & Redhat 6.1 / Repaint() problems?

[Albert Y. C. Lai]

Paul Metcalfe <[EMAIL PROTECTED]> writes:

> This resulted in the following message:
> /opt/jdk117_v1a/bin/../bin/i586/green_threads/java: error in loading 
> shared libraries: /opt/jdk117_v1a/bin/../lib/i586/green_threads/libjava.so:
> undefined symbol: _dl_symbol_value
> 
> Any suggestions on how to get jdk 1.1.7 v1a to run under Redhat 6.1

This may be due to library version mismatches: Redhat 6.1 uses glibc
2.1 and the version of JDK 1.1.7v1a you downloaded uses glibc 2.0.

Make sure you use a JDK version that clearly states "I am for glibc
2.1".  If you have already done so, I am out of ideas.

-- 
[If you post a response, no need to cc me; if you cc me, please say so.]
"When you think you know everything, you can get a Bachelor's.  When
you realize you don't know anything, you can get a Master's.  When you
realize your supervisor also doesn't know anything, you can get a Ph.D."


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Re: Multiple Platforms

[Riyad Kalla]

I think this question got more replies than I've ever seen on this list in a
WHILE :)

Lets all go look at the thread tree for it

-Riyad

- Original Message -
From: "Matthias Pfisterer" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Sent: Tuesday, May 09, 2000 10:05 AM
Subject: Re: Multiple Platforms


> Hi Rick,
>
> Do not run your program with
> java First_tst.class
> Instead, run it with
> java First_tst
>
> Matthias
>
>
> Rick Rothweiler wrote:
> >
> > Hi All:
> > I am fairley new to java,  and receintly wrote a very
> > simple program  in a windows IDE.  I tried to run the .class file on my
> >
> > linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
> > machine says "Exception in thread "main"
> >
> > java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.
> >
> > --
> > To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
>
> --
> Matthias Pfisterer 
>
> Share your knowledge.
> It's a way to achieve immortality.
>
>  (from a nepalese mantra)
>
> Java Sound Examples:
> http://rupert.informatik.uni-stuttgart.de/~pfistere/jsexamples/
> Tritonus, the open source implementation of the Java Sound API:
> http://tritonus.sourceforge.net/
> --
>
>
> --
> To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
>
>


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RE: Multiple Platforms

[[EMAIL PROTECTED]]

Rick,

Another thing you might want to consider is testing your
class with the JDK on the platform you built it 
on. IDE's sometime hide essential information
from the developer until you try to run it 
elsewhere. If you had tried to run this code in
a DOS window with the JDK you would heve seen the same 
behavior and probably have saved yourself some time.

Regards
Tony Dean

>= Original Message From Matthias Pfisterer <[EMAIL PROTECTED]> 
=
>Hi Rick,
>
>Do not run your program with
>   java First_tst.class
>Instead, run it with
>   java First_tst
>
>Matthias
>
>
>Rick Rothweiler wrote:
>>
>> Hi All:
>> I am fairley new to java,  and receintly wrote a very
>> simple program  in a windows IDE.  I tried to run the .class file on my
>>
>> linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
>> machine says "Exception in thread "main"
>>
>> java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.
>>
>> --
>> To UNSUBSCRIBE, email to [EMAIL PROTECTED]
>> with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
>
>--
>Matthias Pfisterer 
>
>Share your knowledge.
>It's a way to achieve immortality.
>
> (from a nepalese mantra)
>
>Java Sound Examples:
>http://rupert.informatik.uni-stuttgart.de/~pfistere/jsexamples/
>Tritonus, the open source implementation of the Java Sound API:
>http://tritonus.sourceforge.net/
>--
>
>
>--
>To UNSUBSCRIBE, email to [EMAIL PROTECTED]
>with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]


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Re: Multiple Platforms

[John Rousseau]

On Tuesday May 9, 2000, Riyad Kalla wrote:

> I think this question got more replies than I've ever seen on this list in a
> WHILE :)
> 
> Lets all go look at the thread tree for it

Can we hold hands and sing Kum-by-ya while we do it?!?!

I'm still waiting to hear how well the imbedded JVM in your pool
skimmer is working. :-P

-John


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Re: Multiple Platforms

[Sabyasachi Gupta[CONTRACTOR]]

yup, Riyad...Strange but true..
Newbie questions are flooded with replies while important
questions might not receive even one..!!!

> 
> I think this question got more replies than I've ever seen on this list in a
> WHILE :)
> 
> Lets all go look at the thread tree for it
> 
> -Riyad
> 
> - Original Message -
> From: "Matthias Pfisterer" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Cc: <[EMAIL PROTECTED]>
> Sent: Tuesday, May 09, 2000 10:05 AM
> Subject: Re: Multiple Platforms
> 
> 
> > Hi Rick,
> >
> > Do not run your program with
> > java First_tst.class
> > Instead, run it with
> > java First_tst
> >
> > Matthias
> >
> >
> > Rick Rothweiler wrote:
> > >
> > > Hi All:
> > > I am fairley new to java,  and receintly wrote a very
> > > simple program  in a windows IDE.  I tried to run the .class file on my
> > >
> > > linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
> > > machine says "Exception in thread "main"
> > >
> > > java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.
> > >
> > > --
> > > To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> > > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
> >
> > --
> > Matthias Pfisterer 
> >
> > Share your knowledge.
> > It's a way to achieve immortality.
> >
> >  (from a nepalese mantra)
> >
> > Java Sound Examples:
> > http://rupert.informatik.uni-stuttgart.de/~pfistere/jsexamples/
> > Tritonus, the open source implementation of the Java Sound API:
> > http://tritonus.sourceforge.net/
> > --
> >
> >
> > --
> > To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
> >
> >
> 
> 
> --
> To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
> 


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Re: Multiple Platforms

[Rob Saul]

John Rousseau wrote:
> 
> I'm still waiting to hear how well the imbedded JVM in your pool
> skimmer is working. :-P

Wouldn't that be a KVM?


--
Rob Saul |


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RE: Multiple Platforms

[Lyanne Truong]

hi.

i've been getting mails from people i don't even know who are asking advices 
on certain problems that are relating to computer technical problems or seem 
to be coming from a java-linux organization. i have no idea how and why i am 
receiving these mailzplease put me off of the mailing list.

thanx,
lyanne

>From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
>To: java-linux <[EMAIL PROTECTED]>
>Subject: RE: Multiple Platforms
>Date: Tue, 09 May 2000 14:07:32 -0600
>MIME-Version: 1.0
>Received: from [192.41.21.66] by hotmail.com (3.2) with ESMTP id 
>MHotMailBAE1CB400068D820F39DC029154204C80; Tue May 09 14:16:50 2000
>Received: (karlasha@localhost) by karlasha.2kweb.net (8.8.5) id NAA20957; 
>Tue, 9 May 2000 13:58:57 -0600 (MDT)
>From [EMAIL PROTECTED] Tue May 09 14:17:56 2000
>Resent-Date: Tue, 9 May 2000 13:58:57 -0600 (MDT)
>Sender: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
>Message-id: <[EMAIL PROTECTED]>
>X-Mailer: WebMail (Hydra) SMTP v3.61
>X-WebMail-UserID: [EMAIL PROTECTED]
>X-EXP32-SerialNo: 2722
>Resent-Message-ID: <[EMAIL PROTECTED]>
>Resent-From: [EMAIL PROTECTED]
>X-Mailing-List: <[EMAIL PROTECTED]> archive/latest/3605
>X-Loop: [EMAIL PROTECTED]
>Precedence: list
>Resent-Sender: [EMAIL PROTECTED]
>
>Rick,
>
>Another thing you might want to consider is testing your
>class with the JDK on the platform you built it
>on. IDE's sometime hide essential information
>from the developer until you try to run it
>elsewhere. If you had tried to run this code in
>a DOS window with the JDK you would heve seen the same
>behavior and probably have saved yourself some time.
>
>Regards
>Tony Dean
>
> >= Original Message From Matthias Pfisterer 
><[EMAIL PROTECTED]>
>=
> >Hi Rick,
> >
> >Do not run your program with
> > java First_tst.class
> >Instead, run it with
> > java First_tst
> >
> >Matthias
> >
> >
> >Rick Rothweiler wrote:
> >>
> >> Hi All:
> >> I am fairley new to java,  and receintly wrote a very
> >> simple program  in a windows IDE.  I tried to run the .class file on my
> >>
> >> linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
> >> machine says "Exception in thread "main"
> >>
> >> java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.
> >>
> >> --
> >> To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> >> with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
> >
> >--
> >Matthias Pfisterer   
> >
> >Share your knowledge.
> >It's a way to achieve immortality.
> >
> > (from a nepalese mantra)
> >
> >Java Sound Examples:
> >http://rupert.informatik.uni-stuttgart.de/~pfistere/jsexamples/
> >Tritonus, the open source implementation of the Java Sound API:
> >http://tritonus.sourceforge.net/
> >--
> >
> >
> >--
> >To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> >with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
>
>
>--
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>


Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com


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Re: Multiple Platforms

[Riyad Kalla]

For me personally that happens because I either don't know the answer, or am
not sure and want to avoid looking like an idiot.

There is SO much unforseen ego floating around when it comes to programming
( in any language ), everyone wants to either be a god, or percieved as a
god, or both!

So from now on I'm going to reply to every email in complete gibberish, just
to break this trend.
:)

-Riyad

- Original Message -
From: "Sabyasachi Gupta[CONTRACTOR]" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Tuesday, May 09, 2000 3:06 PM
Subject: Re: Multiple Platforms


> yup, Riyad...Strange but true..
> Newbie questions are flooded with replies while important
> questions might not receive even one..!!!
>
> >
> > I think this question got more replies than I've ever seen on this list
in a
> > WHILE :)
> >
> > Lets all go look at the thread tree for it
> >
> > -Riyad
> >
> > - Original Message -
> > From: "Matthias Pfisterer" <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>
> > Cc: <[EMAIL PROTECTED]>
> > Sent: Tuesday, May 09, 2000 10:05 AM
> > Subject: Re: Multiple Platforms
> >
> >
> > > Hi Rick,
> > >
> > > Do not run your program with
> > > java First_tst.class
> > > Instead, run it with
> > > java First_tst
> > >
> > > Matthias
> > >
> > >
> > > Rick Rothweiler wrote:
> > > >
> > > > Hi All:
> > > > I am fairley new to java,  and receintly wrote a
very
> > > > simple program  in a windows IDE.  I tried to run the .class file on
my
> > > >
> > > > linux machine with no luck.  Both systems have jdk 1.2.2.  My linux
> > > > machine says "Exception in thread "main"
> > > >
> > > > java.lang.NoClassDefFoundError:  First_tst/class. Any Ideas.
> > > >
> > >
> --
> > > > To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> > > > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
> > >
> > > --
> > > Matthias Pfisterer 
> > >
> > > Share your knowledge.
> > > It's a way to achieve immortality.
> > >
> > >  (from a nepalese mantra)
> > >
> > > Java Sound Examples:
> > > http://rupert.informatik.uni-stuttgart.de/~pfistere/jsexamples/
> > > Tritonus, the open source implementation of the Java Sound API:
> > > http://tritonus.sourceforge.net/
> > > --
> > >
> > >
> > > --
> > > To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> > > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
> > >
> > >
> >
> >
> > --
> > To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
> >
>
>
> --
> To UNSUBSCRIBE, email to [EMAIL PROTECTED]
> with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
>
>


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high performance I/O?

[Dan Kegel]

Anyone here interested in getting Java to handle heavy I/O nicely?   

I'm personally interested in insane things like trying to write an ftp daemon
that can handle 5000 simultaneous clients in Java, but there are probably more sane 
examples.

I have a few notes on the subject at 
  http://www.kegel.com/c10k.html#java
and am musing about how one might support /dev/poll 
  ( http://www.kegel.com/c10k.html#/dev/poll )
in Java under Linux.

Sun is trying to deal with these issues, too; see
http://java.sun.com/aboutJava/communityprocess/jsr/jsr_051_ioapis.html

- Dan

-- 
Entia non sunt multiplicanda praeter necessitatem.


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Re: high performance I/O?

[Juergen Kreileder]

> Dan Kegel writes:

Dan> Anyone here interested in getting Java to handle heavy I/O
Dan> nicely?  I'm personally interested in insane things like
Dan> trying to write an ftp daemon that can handle 5000
Dan> simultaneous clients in Java, but there are probably more
Dan> sane examples.

Dan> I have a few notes on the subject at 
Dan>   http://www.kegel.com/c10k.html#java
Dan> and am musing about how one might support /dev/poll 
Dan>   ( http://www.kegel.com/c10k.html#/dev/poll )
Dan> in Java under Linux.

Dan> Sun is trying to deal with these issues, too; see
Dan> http://java.sun.com/aboutJava/communityprocess/jsr/jsr_051_ioapis.html

I once started to port the JNI-poll interface example from the Solaris
production release JDK to Linux but never had to time finish it.  You
can find a more or less usable version at:
http://guiness.cs.uni-dortmund.de/~kreilede/poller/

The code requires a native threads VM, I recommend 1.2.2-RC4.


Juergen

-- 
Juergen Kreileder, Blackdown Java-Linux Team
http://www.blackdown.org/java-linux.html
JVM'01: http://www.usenix.org/events/jvm01/


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Re: high performance I/O?

[Matt Welsh]

Hi Dan,

> Anyone here interested in getting Java to handle heavy I/O nicely?   

Exactly the topic of my research :-) You should check out Jaguar,
a system I have developed to do high-performance networking and I/O in
Java. It's at
http://www.cs.berkeley.edu/~mdw/proj/jaguar
Using Jaguar I can obtain over 480 megabits/sec bandwidth over our
cluster area network (the same performance as in C). I have also
implemented a near zero-cost serialization technique using Jaguar; 
the idea is to lay out object fields in a form that is "pre-serialized"
(hence the name, "Pre-Serialized Objects"). 

We are also working on building large-scale Internet services in Java.
Many of the problems you talk about on your 'c10k' web page (which is
very good, by the way) are things we are addressing. Along with the 
"Ninja" project here at Berkeley we're building large-scale server 
applications in Java using workstation clusters. One of my colleagues,
Steve Gribble, has done a lot of performance characterization and
tuning of Java applications which require high I/O throughput. What
we're working on now is pulling together Jaguar, his work, and some
other ideas we've had into a new system which obtains very high
I/O performance -- all in Java, of course.

You also might want to read a paper we wrote recently about engineering
systems for high throughput. What we have in mind here is Java,
but it applies to any language and O/S:
http://www.cs.berkeley.edu/~mdw/papers/events.pdf

I'm also on the Expert Group for JSR 51 (the new I/O APIs for the Java 
platform), so hopefully good things will happen there!  

My personal feeling is that there is a lot that will need to happen at
both the Java and the O/S level to get great I/O performance. I am not
sure I agree with many of the discussions in the linux-kernel list
that the right way to get high I/O bandwidth is just to use some 
bastardization of signals; I think that the folks at Rice are a lot
closer to the mark with their novel event-delivery mechanism (by
this I mean http://www.cs.rice.edu/~druschel/usenix99event.ps.gz).

Once you can get Linux by itself to handle the load, delivering the
same performance to Java applications is still very tricky. Using 
native methods won't work -- I have demonstrated that native methods 
can be extremely slow, especially when you pass a large amount of 
data across the JNI interface. JNI is also not expressive enough for 
many things you want to do. As a trivial example, think about how 
you would "wrap" a data structure in C -- outside of the Java heap -- 
in a Java object or array. With JNI, you simply can't do it. Jaguar 
solves this problem, but there are other potential solutions too.

Apart from the native code interface, the traditional Java performance 
issues of compilation, garbage collection, and threading still need to
be solved (especially for Linux, which generally does not have the
state-of-the-art JVMs and compilers available for it). I also believe 
that once you have a large amount of I/O going on in your application, 
that traditional approaches to garbage collection will not be able to cope
with it. But that is another discussion!

So ... it's a very interesting space to work in right now. Demanding 
I/O applications place a lot of new demands on Java (and operating systems
as well). I would be interested in having more discussion with people on
this list about their experiences!

Cheers-

Matt Welsh, [EMAIL PROTECTED]



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java -Xmx1024M doesn't work

[Joseph Shraibman]

I started an application with java -Xmx1024M classname and at about 60megs
I got an OutOfMemoryError.  I tried it again with java -Xmx1073741824
classname and it works.

Verstion is 1.2.2 rc4



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Re: high performance I/O?

[Dan Kegel]

Matt Welsh wrote:
> Exactly the topic of my research :-) You should check out Jaguar,
> http://www.cs.berkeley.edu/~mdw/proj/jaguar
OK, I now link to it from http://www.kegel.com/c10k.html#java

> We are also working on building large-scale Internet services in Java.
> Many of the problems you talk about on your 'c10k' web page (which is
> very good, by the way) are things we are addressing.
Thanks.  The table of contents I just added ought to make it more readable.

> You also might want to read a paper we wrote recently about engineering
> systems for high throughput. What we have in mind here is Java,
> but it applies to any language and O/S:
> http://www.cs.berkeley.edu/~mdw/papers/events.pdf

Looks like a good read.  I now link to it.
(Wish my copy of Ghostscript didn't choke on half the pages!)
 
> I'm also on the Expert Group for JSR 51 (the new I/O APIs for the Java
> platform), so hopefully good things will happen there!

Yes, it should be interesting!
 
> My personal feeling is that there is a lot that will need to happen at
> both the Java and the O/S level to get great I/O performance. I am not
> sure I agree with many of the discussions in the linux-kernel list
> that the right way to get high I/O bandwidth is just to use some
> bastardization of signals; I think that the folks at Rice are a lot
> closer to the mark with their novel event-delivery mechanism (by
> this I mean http://www.cs.rice.edu/~druschel/usenix99event.ps.gz).

The folks at the Linux Scalability Project seem to agree that the 
realtime signal approach isn't the top contender at the moment.
The /dev/poll they implemented for Linux beats the realtime signal 
approach in their tests so far.
See http://www.citi.umich.edu/techreports/reports/citi-tr-00-4.pdf

> So ... it's a very interesting space to work in right now. Demanding
> I/O applications place a lot of new demands on Java (and operating systems
> as well). I would be interested in having more discussion with people on
> this list about their experiences!

Ditto.  And if anyone interested in this happens to be in LA,
drop in on the lajug javaklatch at Equator in old Pasadena at 1pm this 
Saturday and let's talk Java over java :-)

- Dan

-- 
Entia non sunt multiplicanda praeter necessitatem.


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