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?
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