New JDK available

[Berin Loritsch <bl...@apache.org>]

Ladies and gentlemen,

The new Java 1.4.2 runtime/SDK is available, and it has some new performance
enhancements.  Among them is a parallel (concurrent) garbage collector.  It
would be very telling to see how that affects Cocoon's scalability on the
server.

Any enterprising individual up to the challenge?  Since my current work requires
that I do fat client development, I don't have the time to do it myself.  We
have long dreamed of such a garbage collection algorithm, and now we can see
if it pays off.

-- 

"They that give up essential liberty to obtain a little temporary safety
  deserve neither liberty nor safety."
                 - Benjamin Franklin

Re: New JDK available

[Antonio Gallardo <ag...@agsoftware.dnsalias.com>]

Christoph Gaffga dijo:
> Hi,
> we are running Cocoon 2.1m3 on JDK 1.2
> with -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:+UseParNewGC
> -Xmx120 0m -Xms1200m and we see only little perfomance increase. But
> there is something I read in the java perfomance docs, they say: Don't
> use object pools, because the internal garbagge collection ist better
> and does it faster, also with overhead of creating an new instance. Is
> this true for cocoon?

I am already using 1.4.2 in a machine with 768 MB RAM and it is noticiable
faster than the 1.4.1_x. Currently, I am not using any additional
parameter.

The speed improvement of Cocoon in J2SDK 1.4.2 is not only because the
garbage collection (GC) improvement. There are also other improvements
like the class.getName() function. Since cocoon make a intensive use of
this method. It helps Cocoon too. Please check:
http://java.sun.com/j2se/1.4.2/changes.html#runtime

I dont see a plus turning off all the poolers. There are other cost
involved in a pool that a simple improvement of a GC. For example: a
Database Connection is very expensive (in time) to open. Turn off the
database pool will become in a degradation of overall system. This is not
a very smart move.

Please note: I am not telling that a better GC is a bad. But GC is only a
piece of all the cake. :)

Best Regards,

Antonio Gallardo.

Re: New JDK available

[Berin Loritsch <bl...@apache.org>]

Stefano Mazzocchi wrote:

> 
> On Thursday, Jul 24, 2003, at 06:40 America/Guayaquil, Christoph Gaffga 
> wrote:
> 
>> Hi,
>> we are running Cocoon 2.1m3 on JDK 1.2
>> with -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:+UseParNewGC 
>> -Xmx120
>> 0m -Xms1200m and we see only little perfomance increase. But there is
>> something I read in the java perfomance docs, they say: Don't use object
>> pools, because the internal garbagge collection ist better and does it
>> faster, also with overhead of creating an new instance. Is this true for
>> cocoon?
>>
> 
> find it out yourself by turning the max-pool values to 0 in the sitemap. 
> i would very happy to know if the above is true myself.


I large part of that has to do with a very basic assumption:  the cost
to create a new instance is lower than the cost to collect it.  For things
like Strings, Integers, Lists, etc. the cost to create is very small.  For
other things where a heavier resource is attached like network connections,
any kind of I/O, and complex components (ones that take a fair amount of
time to configure and get up and running), then you will find a threshold
where pooling is more effective than just letting the garbage collector
do its thing.

Ideally, your pool would use weak references so that the garbage collector
can still do its thing.


-- 

"They that give up essential liberty to obtain a little temporary safety
  deserve neither liberty nor safety."
                 - Benjamin Franklin

Re: New JDK available

[Stefano Mazzocchi <st...@apache.org>]

On Thursday, Jul 24, 2003, at 06:40 America/Guayaquil, Christoph Gaffga 
wrote:

> Hi,
> we are running Cocoon 2.1m3 on JDK 1.2
> with -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:+UseParNewGC 
> -Xmx120
> 0m -Xms1200m and we see only little perfomance increase. But there is
> something I read in the java perfomance docs, they say: Don't use 
> object
> pools, because the internal garbagge collection ist better and does it
> faster, also with overhead of creating an new instance. Is this true 
> for
> cocoon?
>

find it out yourself by turning the max-pool values to 0 in the 
sitemap. i would very happy to know if the above is true myself.

--
Stefano.

Re: New JDK available

[Christoph Gaffga <cg...@triplemind.com>]

Hi,
we are running Cocoon 2.1m3 on JDK 1.2
with -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -Xmx120
0m -Xms1200m and we see only little perfomance increase. But there is
something I read in the java perfomance docs, they say: Don't use object
pools, because the internal garbagge collection ist better and does it
faster, also with overhead of creating an new instance. Is this true for
cocoon?

Regard
Christoph


----- Original Message -----
From: "Berin Loritsch" <bl...@apache.org>
To: <de...@cocoon.apache.org>
Sent: Wednesday, July 23, 2003 3:23 PM
Subject: New JDK available


> Ladies and gentlemen,
>
> The new Java 1.4.2 runtime/SDK is available, and it has some new
performance
> enhancements.  Among them is a parallel (concurrent) garbage collector.
It
> would be very telling to see how that affects Cocoon's scalability on the
> server.
>
> Any enterprising individual up to the challenge?  Since my current work
requires
> that I do fat client development, I don't have the time to do it myself.
We
> have long dreamed of such a garbage collection algorithm, and now we can
see
> if it pays off.
>
> --
>
> "They that give up essential liberty to obtain a little temporary safety
>   deserve neither liberty nor safety."
>                  - Benjamin Franklin
>