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  1. ObjectWeb/Clustered JDBC

    Peter Eisentraut <peter_e@gmx.net> — 2003-11-21T22:09:07Z

    I was at the ObjectWeb Conference today; ObjectWeb
(http://www.objectweb.org) being a consortium that has amassed quite an
impressive array of open-source, Java-based middleware under their
umbrella, including for instance our old friend Enhydra.  And they
regularly kept mentioning PostgreSQL in their presentations.

To those that are interested in distributed transactions/two-phase commit,
I recommend taking a look at Clustered JDBC
(http://c-jdbc.objectweb.org/).  While this is not exactly the same thing,
it looks to be a pretty neat solution for a similar class of applications.
In particular, it provides redundancy, load balancing, caching, and even
database independence.

-- 
Peter Eisentraut   peter_e@gmx.net

  2. Re: ObjectWeb/Clustered JDBC

    Hans-Jürgen Schönig <hs@cybertec.at> — 2003-11-23T17:12:18Z

    Peter Eisentraut wrote:
> I was at the ObjectWeb Conference today; ObjectWeb
> (http://www.objectweb.org) being a consortium that has amassed quite an
> impressive array of open-source, Java-based middleware under their
> umbrella, including for instance our old friend Enhydra.  And they
> regularly kept mentioning PostgreSQL in their presentations.
> 
> To those that are interested in distributed transactions/two-phase commit,
> I recommend taking a look at Clustered JDBC
> (http://c-jdbc.objectweb.org/).  While this is not exactly the same thing,
> it looks to be a pretty neat solution for a similar class of applications.
> In particular, it provides redundancy, load balancing, caching, and even
> database independence.
> 


It is indeed a nice solution but it is far from ready yet.
Especially the disaster recovery mechanism and things such as adding new 
masters need some more work.
What I really miss is "DECLARE CURSOR". Maybe it will be in there some 
day :).
However, we have done some real testing with sync replication (4 x pg, 1 
x oracle). It performed surprisingly well (the JDBC part, not the Oracle 
one ;) ).
Maybe this will be something really useful within the next few months.

	Cheers,

		Hans

-- 
Cybertec Geschwinde u Schoenig
Ludo-Hartmannplatz 1/14, A-1160 Vienna, Austria
Tel: +43/2952/30706 or +43/660/816 40 77
www.cybertec.at, www.postgresql.at, kernel.cybertec.at

  3. Re: ObjectWeb/Clustered JDBC

    Dave Cramer <pg@fastcrypt.com> — 2003-11-25T11:58:10Z

    Hans,

I don't understand the statement about missing "DECLARE CURSOR" ? The
backend supports it?

Dave
On Sun, 2003-11-23 at 12:12, Hans-Jürgen Schönig wrote:
> Peter Eisentraut wrote:
> > I was at the ObjectWeb Conference today; ObjectWeb
> > (http://www.objectweb.org) being a consortium that has amassed quite an
> > impressive array of open-source, Java-based middleware under their
> > umbrella, including for instance our old friend Enhydra.  And they
> > regularly kept mentioning PostgreSQL in their presentations.
> > 
> > To those that are interested in distributed transactions/two-phase commit,
> > I recommend taking a look at Clustered JDBC
> > (http://c-jdbc.objectweb.org/).  While this is not exactly the same thing,
> > it looks to be a pretty neat solution for a similar class of applications.
> > In particular, it provides redundancy, load balancing, caching, and even
> > database independence.
> > 
> 
> 
> It is indeed a nice solution but it is far from ready yet.
> Especially the disaster recovery mechanism and things such as adding new 
> masters need some more work.
> What I really miss is "DECLARE CURSOR". Maybe it will be in there some 
> day :).
> However, we have done some real testing with sync replication (4 x pg, 1 
> x oracle). It performed surprisingly well (the JDBC part, not the Oracle 
> one ;) ).
> Maybe this will be something really useful within the next few months.
> 
> 	Cheers,
> 
> 		Hans

  4. Re: ObjectWeb/Clustered JDBC

    Peter Eisentraut <peter_e@gmx.net> — 2003-11-25T12:53:46Z

    Hans-Jürgen Schönig writes:

> Especially the disaster recovery mechanism and things such as adding new
> masters need some more work.

Yes, someone is working on automatic recovery (which would extend to
adding new masters by starting recovery from zero).  In fact, they're just
across town from you (together.at).

-- 
Peter Eisentraut   peter_e@gmx.net

  5. Re: ObjectWeb/Clustered JDBC

    Hans-Jürgen Schönig <hs@cybertec.at> — 2003-11-25T13:51:39Z

    Dave,

I know that the backend does - it is an essential feature.
Clustered JDBC parses the statement sent to it in order to find out what 
to do with it. I have played around a little (mostly interactive shell). 
You will find out that Clustered JDBC will complain in this case because 
it doesn't know what to do with it. If you are a tool support load 
balancing and this kind of stuff DECLARE CURSOR can be painful to 
implement - especially across multiple transactions.
Is is a very weak point of the current beta version.

	Regards,

		Hans


Dave Cramer wrote:
> Hans,
> 
> I don't understand the statement about missing "DECLARE CURSOR" ? The
> backend supports it?
> 
> Dave
> On Sun, 2003-11-23 at 12:12, Hans-Jürgen Schönig wrote:
> 
>>Peter Eisentraut wrote:
>>
>>>I was at the ObjectWeb Conference today; ObjectWeb
>>>(http://www.objectweb.org) being a consortium that has amassed quite an
>>>impressive array of open-source, Java-based middleware under their
>>>umbrella, including for instance our old friend Enhydra.  And they
>>>regularly kept mentioning PostgreSQL in their presentations.
>>>
>>>To those that are interested in distributed transactions/two-phase commit,
>>>I recommend taking a look at Clustered JDBC
>>>(http://c-jdbc.objectweb.org/).  While this is not exactly the same thing,
>>>it looks to be a pretty neat solution for a similar class of applications.
>>>In particular, it provides redundancy, load balancing, caching, and even
>>>database independence.
>>>
>>
>>
>>It is indeed a nice solution but it is far from ready yet.
>>Especially the disaster recovery mechanism and things such as adding new 
>>masters need some more work.
>>What I really miss is "DECLARE CURSOR". Maybe it will be in there some 
>>day :).
>>However, we have done some real testing with sync replication (4 x pg, 1 
>>x oracle). It performed surprisingly well (the JDBC part, not the Oracle 
>>one ;) ).
>>Maybe this will be something really useful within the next few months.
>>
>>	Cheers,
>>
>>		Hans
> 
> 


-- 
Cybertec Geschwinde u Schoenig
Ludo-Hartmannplatz 1/14, A-1160 Vienna, Austria
Tel: +43/2952/30706 or +43/660/816 40 77
www.cybertec.at, www.postgresql.at, kernel.cybertec.at

  6. Re: ObjectWeb/Clustered JDBC

    Hans-Jürgen Schönig <hs@cybertec.at> — 2003-11-25T13:54:43Z

    Peter Eisentraut wrote:
> Hans-Jürgen Schönig writes:
> 
> 
>>Especially the disaster recovery mechanism and things such as adding new
>>masters need some more work.
> 
> 
> Yes, someone is working on automatic recovery (which would extend to
> adding new masters by starting recovery from zero).  In fact, they're just
> across town from you (together.at).
> 


Guess who has taught them PostgreSQL ;).

	Hans

-- 
Cybertec Geschwinde u Schoenig
Ludo-Hartmannplatz 1/14, A-1160 Vienna, Austria
Tel: +43/2952/30706 or +43/660/816 40 77
www.cybertec.at, www.postgresql.at, kernel.cybertec.at