One option in AMQP would be to write a custom exchange to handle the concept of delivery at a scheduled time. Exchanges are effectively an extension point in the protocol so that you can customise delivery algorithms.
The Glasgow broker currently doesn't have a well defined API to allow the average end user to plug in new exchanges but this is definitely something I think we will want to get to. Getting use cases such as yours definitely helps us understand what type of thing users might want to be able to do in an exchange. Robert "Noel J. Bergman" <[EMAIL PROTECTED] To: <general@incubator.apache.org> > cc: Subject: Dynamic message selectors and message scheduling 13/08/2006 20:14 Please respond to general In the thread titled "RE: [Proposal] Blaze", James Strachan wrote: > Noel J. Bergman <[EMAIL PROTECTED]> wrote: > > Totally unrelated ... JMS has the ability to create a message filter, but > > one of the limitations is that the filter is applied when the receiver is > > created, rather than when a get operation is executed. This makes sense for > > the push receiver case, but is limiting for the pull receiver case. Does > > AMQP have anything to say about this aspect of messaging, or does it stay > > strictly in the messaging provider space, and away from the client API? > Could you explain a little more about your use case - it sounds > interesting :). Do you only want to fetch a single message with a > different filter per message, or just change the fliter from time to > time. If its the latter then creating JMS consumers is pretty cheap & > you can use any JMS to do that. Though the former, there's no 'give me > a message using filter X' type operation. Sorry for the delayed response. Been busy on many fronts. My particular use case involves selecting the next message in the destination whose scheduled time is less than or equal to now. If there were a "now" operation available in the query language, I wouldn't have to change the selector, but the expression would still have to be constantly reevaluated. And in that case, I'd want both pull and push behavior to be supported. One alternative is writing a broker to handle scheduling, which means posting all messages intended to be rescheduled to the broker, which would post them back when the schedule time occurs, thus handling scheduling in a similar manner to how MQ handles subscriptions. --- Noel --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] This communication is for informational purposes only. It is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction. All market prices, data and other information are not warranted as to completeness or accuracy and are subject to change without notice. Any comments or statements made herein do not necessarily reflect those of JPMorgan Chase & Co., its subsidiaries and affiliates. This transmission may contain information that is privileged, confidential, legally privileged, and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. Although this transmission and any attachments are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by JPMorgan Chase & Co., its subsidiaries and affiliates, as applicable, for any loss or damage arising in any way from its use. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]