Subject Re: [Firebird-Java] JCA Question
Author David Jencks
I think I got overly excited. I think the only property that needs to be
used to locate the appropriate mcf is the url. As you say, everything else
is sorted by in the mcf cache.

thanks

david jencks


On 2002.06.10 14:05:53 -0400 Blas Rodriguez Somoza wrote:
> Hello
>
> Forget the URL question, I don't need to modify that, it is only a
> suggestion, and it seems to be a bad one.
>
> About caching, there is something that I don't understand. I expect
> that MCF can manage any connection to a Database with
> different cri's, because inside the MCF code, there is a caching logic
> that take into account the cri to identify valid dbHandles
> between those in freeDbHandles.
>
> But, according with what you say about caching, it seems that the CRI
> is not enough to identify valid DBhandles, and there are
> other properties in MCF that can't be changed, including the CRI.
>
> To use MCF caching in the FBDriver I need to know which properties
> must be fixed for a MCF instance.
>
> Also MCF must complaint if those properties try to be changed as for
> databaseURL.
>
> Regards
> Blas Rodriguez Somoza
>
> ----- Original Message -----
> From: "David Jencks" <davidjencks@...>
> To: <Firebird-Java@yahoogroups.com>
> Sent: Monday, June 10, 2002 5:02 PM
> Subject: Re: [Firebird-Java] JCA Question
>
>
> > On 2002.06.10 10:34:04 -0400 Blas Rodriguez Somoza wrote:
> > > Hello
> > >
> > > If each MCF is valid for a url, and to avoid errors, I think
> there
> > > must be two patches in the ManagedConnectionFactory
> > >
> > > 1.- Because the database can be only one, then it is an error to
> change
> > > the database, and the MCF must throw an exception if the
> > > setDatabase method tries to change the database.
> > > 2.- If a connection tries to be created before the database is set,
> then
> > > an exception must be throw.
> >
> > I'm not sure these are high priority, but they are fine with me.
> > >
> > > I suppose, but I'm not sure, that if we add all the connection
> > > parameters to CRI including the URL, the ManagedConnectionFactory
> > > can manage connections to any accesible FB database with only one
> > > ManagedConnectionFactory instance.
> > >
> > > I analyze that because the connection times for repeated
> connection
> > > to the same database through FBDriver are to high. After
> > > some search the problem appears because for each connection a MCF is
> > > created, and so there is no caching.
> > >
> > > If each MCF is valid for all the connections to a url, then
> FBDriver
> > > must create a collection (URL,MCF) and reuse MCF. The
> > > connection parameters excluding url are in the CRI and it seems that
> MCF
> > > can manage different CRI's.
> >
> > This is really against what the jca spec recommends. I think it is a
> > better idea to cache mcf in the FBDriver using all the supplied
> properties
> > that are set as mcf properties. You would also have to substantially
> > modify the isSameRM() method and might well have to deal with combining
> > jta/xa support with internal firebird xa support. This is something
> that is
> > so complicated with no apparent benefits that I will not work on it.
> Please
> > try the simple solution of caching by properties in mcf first. If you
> > pursue adding the URL to CRI against my advice please explain how the
> > interactions between a jta tx manager and the firebird tx manager will
> > work.
> >
> > thanks
> > david jencks
> >
> > >
> > > Regards
> > > Blas Rodriguez Somoza
> > >
> > > ----- Original Message -----
> > > From: "David Jencks" <davidjencks@...>
> > > To: <Firebird-Java@yahoogroups.com>
> > > Sent: Monday, June 10, 2002 3:28 PM
> > > Subject: Re: [Firebird-Java] JCA Question
> > >
> > >
> > > > Each instance of a ManagedConnectionFactory should connect to one
> > > instance
> > > > of the EIS. The instance of the EIS should be specified somehow in
> the
> > > > ManagedConnectionFactory configuration properties: the spec
> suggests
> > > some
> > > > properties such as server, and url as I recall. I interpreted
> > > "instance of
> > > > EIS" to mean firebird database, as this seems to me to be what is
> > > implied
> > > > by several passages in the spec. If we changed to mean "firebird
> > > server"
> > > > or "firebird server accessible through any chain of firebird
> servers
> > > from
> > > > an original server" we would be relying on firebird internal 2pc
> > > > capabilities and internal transaction manager as well as an
> external
> > > jta
> > > > transaction manager. I don't see any reason to try to do this,
> even if
> > > it
> > > > is possible.
> > > >
> > > > david jencks
> > > >
> > > >
> > > > On 2002.06.10 09:11:53 -0400 Blas Rodriguez Somoza wrote:
> > > > > Hello
> > > > >
> > > > > I have a doubt about ManagedConnectionFactory, I don't know
> if
> > > one
> > > > > ManagedConnectionFactory can be used for several Firebird
> > > > > Databases or there must be one ManagedConnectionFactory instance
> for
> > > each
> > > > > database (url).
> > > > >
> > > > > According to specification it seems that one
> > > ManagedConnectionFactory
> > > > > can be used to connect to every resource of the same type,
> > > > > but if this is true it seems that there is a bug in the driver.
> > > > >
> > > > > Regards
> > > > > Blas Rodriguez Somoza.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
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