You need to make sure the query for changes is indexed and fast for the DB.
As bruce suggested, you could add a boolean column that would indicate that
the row has been changed (it can be populated using a trigger),
then you just have to index it and query the columns that have this boolean
true.
You could even call a stored procedure from servicemix so that the modified
records
are returned and set back to false at the same time (instead of having
servicemix
update them later).
On Jan 24, 2008 11:16 PM, cchalmers <[EMAIL PROTECTED]> wrote:
>
> Hi Bruce,
>
> thx for your reply.
> Well basically were setting up a small test application to prove and gain
> knowledge of an Event Driven Architecture. Its based on a simple
> application
> whereby someone can make a travel booking via a web page. The data is
> persisted in a mysql database. I then want to alter the data using a sql
> script meaning the flight would be delayed. This should trigger an event
> afterwhich I want the application to notify all passengers on the flight
> via email or sms. Our setup uses Grails for the web-pages, servicemix as
> esb
> and mysql as database.
>
> I could poll the database every so often from the esb looking for records
> that have been changed but am apprehensive about the load on the database
> should there be lots of records in a real life situation. I was interested
> in using triggers from the database but how to pass an event from a db
> through to servicemix? I would be interested in you thoughts on that one.
>
> Appreciate your help
>
> Colin
>
>
>
>
> bsnyder wrote:
> >
> > On Jan 19, 2008 2:21 PM, cchalmers <[EMAIL PROTECTED]> wrote:
> >>
> >> Hi,
> >>
> >> Together with a colleague I've just started a small project to build up
> >> knowledge concerning EDA and have currently chosen ServiceMix as the
> >> implementation tool. Bear with me as a lot of this is new new to me.
> >>
> >> The case we're trying to implement is a travel booking-system.
> Employees,
> >> customers and airlines can be persisted after-which a customer can make
> a
> >> booking etc.
> >>
> >> One of the things we want to prove is that when data changes in the
> >> database
> >> that an event is generated and action undertaken. For example if the
> >> flight
> >> data changes we want to send an sms to the passengers about the time
> >> change.
> >>
> >> I read that others are connecting to databases via the spring jdbc
> >> template.
> >> The question is how an event as generated concerning the changed data?
> As
> >> far as I see it there are two paths:
> >>
> >> 1. Continually polling the database from servicemix looking for changed
> >> records which would have to have a last-modified data and then
> generating
> >> an
> >> event
> >> 2. Working with triggers in the database which would somehow have to
> send
> >> an
> >> event to servicemix so that the sms can be sent.
> >>
> >> Is there a third (or more) option which I'm unaware of and is standard
> in
> >> servicemix?
> >> Perhaps I'm misunderstanding the EDA concept and how servicemix
> achieves
> >> this?
> >
> > Your understanding is correct; there are basically two ways to
> > determine if data in a database has changed:
> >
> > 1) Poll the database with an external application, or
> > 2) Configure a trigger in the database to notify an external application
> >
> > Of course, the implementation of #1 above can be implemented in many,
> > many different ways. There are advantages and disadvantages to each
> > and the oly way to find a solution that will work for you is by using
> > specifics about your environment and your use case.
> >
> > Bruce
> > --
> > perl -e 'print
> > unpack("u30","D0G)[EMAIL PROTECTED]&5R\"F)R=6-E+G-N>61E<D\!G;6%I;\"YC;VT*"
> > );'
> >
> > Apache ActiveMQ - http://activemq.org/
> > Apache Camel - http://activemq.org/camel/
> > Apache ServiceMix - http://servicemix.org/
> > Apache Geronimo - http://geronimo.apache.org/
> >
> > Blog: http://bruceblog.org/
> >
>
> --
> View this message in context:
> http://www.nabble.com/ServiceMix---EDA---Database-tp14975289s12049p15076425.html
> Sent from the ServiceMix - User mailing list archive at Nabble.com.
>
>
--
Cheers,
Guillaume Nodet
------------------------
Blog: http://gnodet.blogspot.com/
