Re: [JBoss-dev] Why is new ObjectName() so slow?

[Larry S. <lsa...@sp...>]

Sorry if I'm just adding noise, but...

It sounds like the biggest problem is that you keep parsing the same string
into it's canonical form.  Can't the jmx server cache the canonical names of
the given ObjectNames?  Then, for each new ObjectName(), check the cache,
and if it doesn't exist, parse and cache the result.  Am I missing
something?

-Larry

----- Original Message -----
From: "Juha-P Lindfors" <jpl...@cc...>
To: "marc fleury" <mar...@jb...>
Cc: "Jboss-Development@Lists. Sourceforge. Net"
<jbo...@li...>
Sent: Sunday, April 28, 2002 12:36 PM
Subject: RE: [JBoss-dev] Why is new ObjectName() so slow?


> On Sun, 28 Apr 2002, marc fleury wrote:
>
> > |because an object name contains a set of properties that need to be
> > |parsed and may also be a pattern which needs to be determined
> >
> > right the value=name pairs
> >
> > |the current implementation does this eagerly at object name creation
> > |time
> >
> > can we do this lazily? can't we build equality and hash on the FULL
string?
> >
>
> no, we need a canonical presentation for equality check (because the
> "name" is a set of properties, not just an array of characters.. we need
> to sort the properties before we can check for equality)
>
>
> > it strikes that the eager parsing is silly (eats up 50% of the time !!!)
and
> > only really useful in querying?  Can you think of optimizations?
>
> the optimizations that we can do inside ObjectName would only include
> possibly optimizations to Java's string handling, maybe replacing generic
> collections with type specific ones, and avoiding Collections.sort() (I
> don't know how it is implemented or how well it performs).
>
> However, the problem with even these optimizations is that Sun plans to
> push JMX as part of JDK from the next 1.5 version on. They however have no
> plans to publish an SPI which means whatever is inside javax.management
> packages will from the next version on be Sun's implementation. And as you
> and I well know, Sun's implementation isn't exactly performing or
> industrial strength.
>
> The question at the moment is, why do you need to create an object name
> per invocation? Is it possible to cache the object names by mapping them
> to *real* identifies as opposed to this property nonsense? (how many
> MBean's do you imagine having in your server, could you create the object
> names for them on the server side and lookup the same instances from a
> "cache" -- I know it sounds ass backwards but given then future plans on
> JMX it would be best to avoid too much reliance on the JMX classes
> themselves.
>
>
> -- Juha
>
>
>
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