jython-users

[Jython-users] Jython startup slowness

[Sebastien P. <Seb...@is...>]

Hi all,

I have in my classpath every possible jar on my system. The problem is
that at startup Jython looks in every jar without caching the
information somewhere. This leads to a +20s slowdown at each runtime...

Is there a possiblility to disable this step and only give jars that are
needed, or maybe turn on a caching property that may be off?

  -- Sebastien.

Re: [Jython-users] Jython startup slowness

[Robert W. B. <rb...@di...>]

On Mon, 10 Sep 2001, Sebastien Pierre wrote:
> Hi all,
>
> I have in my classpath every possible jar on my system. The problem is
> that at startup Jython looks in every jar without caching the
> information somewhere. This leads to a +20s slowdown at each runtime...
>
> Is there a possiblility to disable this step and only give jars that are
> needed, or maybe turn on a caching property that may be off?

Is there an error message each time the cache is unable to write the
package cache?  Do permissions not allow you to write to the cachedir?
Are you referring to PyServlet or some tool that uses sys.add_extdir?

You can limit the jars in your classpath to limit the startup overhead.
This is also good because extraneous jars seems to have a performance
effect on Java loading anyway (or is it just me?).

It would be better to get the cache to work property as it seems an
important optimization.  Make sure permissions allow writing the cachedir
and maybe double check to see if the python.home property is correct.

-rb

Re: [Jython-users] Jython startup slowness

[Sebastien P. <Seb...@is...>]

"Robert W. Bill" wrote:

> It would be better to get the cache to work property as it seems an
> important optimization.  Make sure permissions allow writing the cachedir
> and maybe double check to see if the python.home property is correct.

Actually the fact excerpt just made it ;)

Cheers,
   -- Sebastien.

Re: [Jython-users] Jython startup slowness

[dman <ds...@ri...>]

On Mon, Sep 10, 2001 at 10:52:18AM +0200, Sebastien Pierre wrote:

| I have in my classpath every possible jar on my system. The problem is

It is better to have only what you need for a given app.  This is
especially true when you might have more than one version of a given
package for different purposes.  Just an example, you might have
multiple JVMs and then you would need different classes.zip/rt.jar
files for each one.

| that at startup Jython looks in every jar without caching the
| information somewhere. This leads to a +20s slowdown at each runtime...

It is supposed to.  I have been getting "can't write to cache" errors
lately but I have no idea why (windows/cygwin, dir is writable).  I
have "new" jars pretty frequently anyways.

-D

Re: [Jython-users] Jython startup slowness

[<bc...@wo...>]

[dman]

>... I have been getting "can't write to cache" errors
>lately but I have no idea why (windows/cygwin, dir is writable).  I
>have "new" jars pretty frequently anyways.

Commonly seen when moving a jython installation to a different
directory. The cache index (packages.idx) contains absolute path names
to the the individual jar indexes (.pkc). After a move the paths insode
packages.idx doesn't exists anymore and it can't updated them.

Normally the workaround is easy: just delete cachedir

regards,
finn