On 6 September 2010 16:46, Gordon Sim <[email protected]> wrote: > On 09/06/2010 04:20 PM, Robbie Gemmell wrote: >> >> Hi all, >> >> I would like to flag up a recent change I made for comment. >> >> In order to update the patch for QPID-2418 to allow the 0-10 Java >> client to properly handle DurableSubscriptions in the face of >> adding/removing/changing selectors for a given subscription name, I >> had to remove an arbitrary addition of the x-match argument to the >> bindings created by the 0-10 client (see below). This was corrupting >> the arguments sent to the broker and was not added when performing >> checks using isBound(), so I was seeing apparent failures to match >> arguments I (thought I) had just bound. >> >> The only reason I know for this to be there is so that users dont need >> to specify an option when using eg the Headers Exchange. As this is a >> required option im not sure adding it for them is the correct >> behaviour, but if this is truly the desired outcome then i think it >> should be performed by making the broker lenient to its exclusion >> rather than the other way around. I note the the C++ broker plays >> hardball in this situation and demands the value be set. > > Yes, the "headers_exchange_requires_match_arg" rule in the spec states: > > When creating a binding between an exchange E, of type > headers and any queue Q the arguments field MUST contain > a key "x-match" to a value of type str8 which must equal > either "any" or "all". If the arguments field does not > contain a key "x-match" then an exception of type > invalid-argument MUST be raised. > > However as far as I'm aware, none of the other clients add it by default. > I'm not sure I see much value in the code you have removed, especially given > the problems you point out. > > Does the java broker have a default if no explicit x-match is specified?
Reading the spec on this would have cleared that right up, oops, glad to hear the other clients arent doing it though :) I think it defaults to 'all' in the Java broker thanks to Java initialisation defaults, plus im not sure think the 0-9 spec is quite as clear on what the behaviour should be anyway so it is probably just historically lazy. Dont think anyone is really using it anyway. Robbie > > --------------------------------------------------------------------- > Apache Qpid - AMQP Messaging Implementation > Project: http://qpid.apache.org > Use/Interact: mailto:[email protected] > > --------------------------------------------------------------------- Apache Qpid - AMQP Messaging Implementation Project: http://qpid.apache.org Use/Interact: mailto:[email protected]
