Has anyone done much work with server-side push and AJAX/J? (XML or JSON) As best I can tell, the ideal solution to this would be the multipart/x-mixed-replace MIME type. Mozilla''s XMLHttpRequest now has support for this, so this is on people''s minds, but how to make it work on the server end? You have to keep a connection open.....and a process on the server to go with it. Problems with scaling to 100 users? 1,000? 10,000? To pose a scenario, I''ve got a database app. When "Charlie" updates table "foo", which "Bobby" is currently looking at, somehow the server process maintaining Bobby''s data stream needs to find out about the table update so it can send the data down the connection to Bobby''s browser. So, triggers in the RDBMS, but how to "push" that information from the DB to Bobby''s process? Does Perl, Ruby, or some other server-side language support "listening", or am I thinking about this the wrong way? And of course, another question: Will IE ever support multipart/x-mixed-replace? Is there a workaround? -Felipe Gasper Cincinnati, OH -- Felipe M. L. Gasper, conductor/singer http://felipegasper.com Judge ideas, not people. Love people, not ideas.
> To pose a scenario, I''ve got a database app. When "Charlie" > updates table > "foo", which "Bobby" is currently looking at, somehow the server > process maintaining Bobby''s data stream needs to find out > about the table > update so it can send the data down the connection to Bobby''s > browser. So, > triggers in the RDBMS, but how to "push" that information > from the DB to > Bobby''s process? Does Perl, Ruby, or some other server-side language > support "listening", or am I thinking about this the wrong way?Before XMLHttpRequest, we implemented a push technique (in Oracle & Java) as follows : - New DB events fired triggers that posted to Oracle Advanced Queue (AQ). - The Java tier kept a list of registered clients and posted new info via a servlet with a persistent HTTP connection to a hidden frame in the browser. The servlet (indirectly) monitored the Oracle AQ with Java JMS consumers. - Some client side javascript moved the data around accordingly and made it visible to the user. So long as you don''t mind your client polling via XMLHttpRequest, things are more straight forward now. You can push data from the DB into a queue of some kind in your chosen server technology and use an synchronous request to check for changes. We have just achieved a similar thing for message broadcasts... HTH Matt *********************************************************************************** The Royal Bank of Scotland plc. Registered in Scotland No 90312. Registered Office: 36 St Andrew Square, Edinburgh EH2 2YB. Authorised and regulated by the Financial Services Authority This e-mail message is confidential and for use by the addressee only. If the message is received by anyone other than the addressee, please return the message to the sender by replying to it and then delete the message from your computer. Internet e-mails are not necessarily secure. The Royal Bank of Scotland plc does not accept responsibility for changes made to this message after it was sent. Whilst all reasonable care has been taken to avoid the transmission of viruses, it is the responsibility of the recipient to ensure that the onward transmission, opening or use of this message and any attachments will not adversely affect its systems or data. No responsibility is accepted by The Royal Bank of Scotland plc in this regard and the recipient should carry out such virus and other checks as it considers appropriate. Visit our websites at: http://www.rbs.co.uk/CBFM http://www.rbsmarkets.com ********************************************************************************