updating info 6

[rvy2k]

Hi everybody,

I have multiple client application that are updating a Microsoft Access database on a server.
Each client have an up-to-date representation of the data on the database.
I would like the client to be notified each time the database is changed by another client so that it can update its representation.
What would be the best way to handle it? I heard about a file modified function, but then isnt it going to slow down the program if it has to query every time to know if the database was modified or not? Moreover it is not real time...

Thanks for your help!

 

[Guest_imported]

JMS would be a good solution to multicast to all concerned parties. You could frame the change in an XML message passed to all of the clients. It does mean learning a new API and integrating another product (the Message Server). You could use sockets between clients and servers to broadcast the messages, but this means handling all the client pooling and queueing yourself. All depends on your resources, expertise, time etc.

I personally like JMS and there are open source vendors out there which you could use for free. Be aware of firewall issues if clients are outside of firewalls (grrr - so necessary but a pain in the ar*e!).

Hope this helps

Derren

 

[rvy2k]

Thanks a lot LittleWing.
How would I send the message updateDataNow from the application on the server?
Could you tell me more about JMS (a link or something)?
What if I use RMI instead?

Thanks for your comment DerrenB,
Could you tell me more about JMS (a link or something)?
What if I use RMI instead?

Thanks again for your help!

 

[meadandale]

Here's a few links that should get you up to speed:

http://java.sun.com/products/jms/

http://www.jguru.com/faq/home.jsp?topic=JMS

http://www.execpc.com/~gopalan/jms/jms.html

http://www.javaworld.com/javaworld/jw-02-2000/jw-02-jmsxml.html

Have fun

Charle

 

[rvy2k]

Thanks a lot meadandale!

 

[techg]

hi
if u r using a application like that why dont u try the push and pull technology try that it should free up more resources of u server and even shall speed the process of updating a little faster
thank u
techg