Hi all, I have committed the initial implementation in revision r199114 where it does provide selector support for Queues and Durable Topics. When looking at the source i could find that we were already having message selectors for Topics and there was no need to re-implement it.
Since there are a whole list of different patterns that can be used in selector strings we need to test them extensively against both topics/queues and identify which literals,logics etc. are supported by selectors and which are not. As the first phase we are going to test against the selectors in [1] as well as testing against all the JMS headers and properties. As per the JMS Headers the following headers are supported with selectors, where a client can set and send to broker. *JMSCorrelationID JMSReplyTo JMSType * The below header properties will not be filtered by broker since they are handled by the JMS provider and set into the default values at broker side as describer here. [2] *JMSPriority JMSExpiration JMSDeliveryMode* Once these are tested we can update the MB 2.2.0 docs with supported syntaxes and headers for Message Selectors. Thanks! Ishara [1] http://www.novell.com/documentation/extend5/Docs/help/Composer/books/JMSAppendixB.html [2] http://docs.oracle.com/cd/E19798-01/821-1841/bnces/index.html On Thu, Mar 27, 2014 at 10:34 AM, Pamod Sylvester <pa...@wso2.com> wrote: > +1 to handle it from the server side, also considering the fact of sending > irrelevant messages to client will be an additional network overhead. > > > On Thu, Mar 27, 2014 at 10:18 AM, Ishara Premadasa <ish...@wso2.com>wrote: > >> Hi all, >> >> We are going to implement message selectors support [1] into WSO2 Message >> Broker where a message consumer is allowed to specify the messages it is >> interested by using a selector string and the broker (JMS provider) does >> the filtering of messages according to that query. The syntax of the JMS >> selector expression is based on a subset of SQL92, mentioned here [2]. >> >> Message selectors can be implemented either using the client-side or >> server-side. As the first try i have tried with filtering the messages in >> the client-side where the filtering happens after the message is dispatched >> into client side. >> >> However we had some considerable issues with this method since the >> messages which were rejected by the consumer's selector cannot be >> re-delivered to other consumers who do not have filters, and those messages >> were stuck in queue. Therefore since this was not possible to be handled in >> the client-side we moved the implementation server-side. >> >> Therefore with the current implementation at server side when the >> messages are sending out to subscribers we check whether the message >> matches the filters and if so that will be given out to the subscriber. If >> not that message will be removed from already read messages, hence it can >> be given to another matching subscriber in the next round. >> >> I will be updating this thread with the progress of the implementation. >> The plan is to send this out with 2.2.0 version, however if takes more time >> this will be definitely available with MB 3.0.0 version. Any >> feedback/suggestions are welcome. >> >> Thanks! >> Ishara >> >> [1] http://docs.oracle.com/cd/E19798-01/821-1841/bncer/index.html >> [2] >> http://www.novell.com/documentation/extend5/Docs/help/Composer/books/JMSAppendixB.html >> >> >> -- >> Ishara Premasada >> Software Engineer, >> WSO2 Inc. http://wso2.com/ >> >> >> *Blog : http://isharapremadasa.blogspot.com/ >> <http://isharapremadasa.blogspot.com/>Twitter : >> https://twitter.com/ishadil <https://twitter.com/ishadil> Mobile : >> +94 714445832 <%2B94%20714445832>* >> >> >> > > > -- > *Pamod Sylvester * > * Software Engineer * > Integration Technologies Team, WSO2 Inc.; http://wso2.com > email: pa...@wso2.com cell: +94 77 7779495 > -- Ishara Premasada Software Engineer, WSO2 Inc. http://wso2.com/ *Blog : http://isharapremadasa.blogspot.com/ <http://isharapremadasa.blogspot.com/>Twitter : https://twitter.com/ishadil <https://twitter.com/ishadil>Mobile : +94 714445832*
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