Re: First connection to Xindice takes too much time inservlets?

["Mark J. Stang" <ma...@earthlink.net>]

I have seen all kinds of various delays.   They are all related to the loading
the DatabaseManager.   If you time it, it is the
DatabaseManager.registerDatabase().
I wrote a simple CollectionPool that is a Singleton to load it one time.   If
you
are doing servlets, load at startup and put it into the app session.   Also,
each time
you create a collection there is a bit of time.   According to Kimbro you can
keep the collections around.   Your issue would be whether to share collections

between sessions.   From my experience, start a thread to create the
collections
when ever the client connects and keep them around until the session dies.

HTH,

Mark

Alex McLintock wrote:

> At 11:54 30/06/02, Devrim Ergel wrote:
> >I'm using Xindice in Tomcat Servlet environement. I logged elapsed time
> >for connection with XML:DB API. The result is ~750ms for first connection.
> >But next connections takes between 20-40ms.I do not use any connection
> >pooling mechanism so every request to servlet try to reconnect to Xindice.
>
> We were discussing something similar in the Cocoon mailing list.
> Apparently Cocoon does not use any Connection Pool for its connections
> to XIndice and there may in fact be a memory leak with opening up new
> connections each time.
>
> However let me make a guess....
>
> I think the XML:DB protocol is based upon an http connection request and
> response. http 1.0 by does not keep any connection alive between separate
> requests. However I think that http1.1 does. This means that subsequent
> requests may be faster than the first one.
>
> I'm not expert in this but that might give you a few leads to be getting on
> with.
>
> Other possibilities are that there are services in XINdice which only start
> up when they are requested - but that is a big guess. You can test that by
> automatically making a request when you start up the server....
>
> Alex McLintock
>
> Openweb Analysts Ltd, London: Software For Complex Websites
> http://www.OWAL.co.uk/
> Free Consultancy for London Companies thinking of Open Source Software.

--
Mark J Stang
System Architect
Cybershop Systems

Re: First connection to Xindice takes too much time inservlets?

[Devrim Ergel <de...@parsera.com>]

Hello,
CollectionPool class resolved the problem (it's an adaptation of
ConnectionPool class found on the web). I've noticed that more time elapsed
on Getting Collection.
Servlet uses different collections, therefore I created a Hastable of
CollectionPool class at Init()function.

Latest performance numbers are very good and no wait for first connections:
Database connection + Get Collection + Get Document = average 18ms

Regards
Devrim Ergel

----- Original Message -----
From: "Mark J. Stang" <ma...@earthlink.net>
To: <xi...@xml.apache.org>
Sent: Sunday, June 30, 2002 7:29 PM
Subject: Re: First connection to Xindice takes too much time inservlets?


> I have seen all kinds of various delays.   They are all related to the
loading
> the DatabaseManager.   If you time it, it is the
> DatabaseManager.registerDatabase().
> I wrote a simple CollectionPool that is a Singleton to load it one time.
If
> you
> are doing servlets, load at startup and put it into the app session.
Also,
> each time
> you create a collection there is a bit of time.   According to Kimbro you
can
> keep the collections around.   Your issue would be whether to share
collections
>
> between sessions.   From my experience, start a thread to create the
> collections
> when ever the client connects and keep them around until the session dies.
>
> HTH,
>
> Mark
>
> Alex McLintock wrote:
>
> > At 11:54 30/06/02, Devrim Ergel wrote:
> > >I'm using Xindice in Tomcat Servlet environement. I logged elapsed time
> > >for connection with XML:DB API. The result is ~750ms for first
connection.
> > >But next connections takes between 20-40ms.I do not use any connection
> > >pooling mechanism so every request to servlet try to reconnect to
Xindice.
> >
> > We were discussing something similar in the Cocoon mailing list.
> > Apparently Cocoon does not use any Connection Pool for its connections
> > to XIndice and there may in fact be a memory leak with opening up new
> > connections each time.
> >
> > However let me make a guess....
> >
> > I think the XML:DB protocol is based upon an http connection request and
> > response. http 1.0 by does not keep any connection alive between
separate
> > requests. However I think that http1.1 does. This means that subsequent
> > requests may be faster than the first one.
> >
> > I'm not expert in this but that might give you a few leads to be getting
on
> > with.
> >
> > Other possibilities are that there are services in XINdice which only
start
> > up when they are requested - but that is a big guess. You can test that
by
> > automatically making a request when you start up the server....
> >
> > Alex McLintock
> >
> > Openweb Analysts Ltd, London: Software For Complex Websites
> > http://www.OWAL.co.uk/
> > Free Consultancy for London Companies thinking of Open Source Software.
>
> --
> Mark J Stang
> System Architect
> Cybershop Systems
>
>