THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
The JMS 2.0 specification adds support for shared subscriptions. QPIDJMS-220 outlines how the Qpid JMS client maps the JMS semantics to AMQP terms. This document outlines how the broker responds to those AMQP performatives.
Connection Open
“SHARED-SUB” capability should be set on offered capabilities.
Link Attach
Assumptions:
- If source is set the address is specified as “exchange/binding” and exchange with name “exchange” exists. If exchange with name “exchange” does not exist the link is refused with error “not found”.
- Link does not exist. for Link reattachment see below.
- Terminus durability : NO means 0, YES means 1 or 2.
- When creating a queue its life time policy will be derived from source expiry policy as follow:
- “link-detach” becomes “delete on no outbound link”
- “session-end” becomes “delete on session end”
- “connection-close” becomes “delete on connection close”
- “never” becomes “permanent"
- SHARED and GLOBAL are derived from Source capabilities if Source is set and from Link capabilities otherwise
...
Not Null Source | SHARED | GLOBAL | TERMINUS DURABILITY | outcome |
YES | NO | NO | NO | Create a non-durable queue with random name and exclusivity policy “link”. Bind queue to exchange “exchange” using binding key “binding”. Broker replies with attach having capability “topic” on a source and attach offered capability “SHARED_-SUB”. |
YES | NO | NO | YES | Create a durable queue with name derived from link name, container id and source durability. Exclusivity policy is set to “link”. Bind queue to exchange. Broker replies with attach having capability “topic” on a source and attach offered capability “SHARED_-SUB”. If queue already exists the link should be refused with error “resource locked” |
YES | NO | YES | NO | The same as for SHARED=NO, GLOBAL=NO and DURABLE=NO |
YES | NO | YES | YES | Create a durable queue with name derived from link name, global name space and source durability. Exclusivity policy is set to “link”. Bind queue to exchange. Broker replies with attach having capabilities “topic” and “global” on a source and attach offered capability “SHARED_-SUB”. If queue already exists the link should be refused with error “resource locked” |
YES | YES | NO | NO | Create a non-durable queue with name derived from link name (up to “|”), container id and source durability. Exclusivity policy is set to “shared”. Bind queue to exchange. Broker replies with attach having capabilities “topic” and “shared” on a source and attach offered capability “SHARED_SUB”. If queue already exists and filters and/or binding key are not the same as derived from attach source, then:
If existing queue exclusivity policy is not “shared”, then link creation is refused with error “resource locked”. If existing queue lifetime and/or durability are different from expected, then link creation is allowed but the source fields in the reply should be modified accordingly. |
YES | YES | NO | YES | Create a durable queue with name derived from link name (up to “|”), container id and source durability. Exclusivity policy is set to “shared”. Bind queue to exchange. Broker replies with attach having capabilities “topic” and “shared” on a source and attach offered capability “SHARED_SUB”. See above, if queue exists |
YES | YES | YES | NO | Create a non-durable queue with name derived from link name (up to “|”), global namespace and source durability. Exclusivity policy is set to “shared”. Bind queue to exchange. Broker replies with attach having capabilities “topic”, “shared” and “global” on a source and attach offered capability “SHARED_SUB”. See above, if queue exists |
YES | YES | YES | YES | Create a durable queue with name derived from link name (up to “|”), global name space and source durability. Exclusivity policy is set to “shared”. Bind queue to exchange. Broker replies with attach having capabilities “topic”, “shared” and “global” on a source and attach offered capability “SHARED_SUB”. See above, if queue exists |
NO | NO | NO | N/A | Look for queue with name derived from link name, container id and “true” durability. If queue exists and there is no consumer, delete queue. Reply with attach having null sourceAttach the link with the Source set. If queue exists but there is/are consumer(s)does not exist, refuse the link with error “resource locked”. If queue does not exist, refuse the link with error “not found”. TODO: This breaks the AMQP spec “not found”. |
NO | NO | YES | N/A | Look for queue with name derived from link name, global name space and “true” durability. If queue exists and there is no consumer, delete queue. Reply with attach having null source.If queue exists but there is/are consumer(s), refuse Attach the link with error “resource locked”the Source set. If queue does not exist, refuse the link with error “not found” . TODO: This breaks the AMQP spec |
NO | YES | NO | N/A | Look for queue with name derived from link name (up to “|”), container id and “true” durability. If queue exists and there is no consumer, delete queue. Reply with attach having null source.If queue exists but there is/are consumer(s), refuse Attach the link with error “resource locked”the Source set. If queue does not exist, refuse the link with error “not found”. |
NO | YES | YES | N/A | Look for queue with name derived from link name (up to “|”), global name space and “true” durability. If queue exists and there is no consumer, delete queue. Reply with attach having null source Attach the link with the Source set. If queue exists but there is/are consumer(s)does not exist, refuse the link with error “resource locked”.If queue does not exist, refuse the link with error “not found”. |
TODO: Attach with null Source from an AMQP perspective should not error with resource-locked or not-found. The JMS mapping seems to require this.
Link re-Attach
If link exists and the queue exists see the instructions for the existing queue for SHARED=YES.
If link exists and the queue does not exist, recreate a queue as described in corresponding instructions above.
Pseudo Code
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Link Detach
If the Detach has close=true
- If Link Source has capability "topic" and queue has no consumers, the queue is deleted and the Link is Detached
- If Link Source has capability "topic" and queue has consumers, the Link is detached with error(resource-locked)
- if Link Source does not have capability "topic", the Link is detached
Pseudo Code
The above described behaviour results in the following pseudo code. Where the below differs from the above the above is considered normative:
| No Format |
|---|
if Link does not exists |
| No Format |
if Link does not exists if Source is set if Source has SHARED capability subscription_name = Link name up to (excluding) “|” exclusivity_policy = “SHARED” if Source elseis set if Source has subscription_name = Link nameSHARED capability exclusivity_policy = “LINK” subscription_name = Link ifname Sourceup hasto GLOBAL capability(excluding) “|” nameexclusivity_spacepolicy = global name space“SHARED” else subscription_name_space = container-idLink name space nameexclusivity_policy = get_queue_name(“LINK” if Source has GLOBAL capability name_space, name_space = global name space subscription_name, else name_space = name space derived from container-id Source Durability) queue_name = get_queue_name( if queue with name exists name_space, if has same exclusivity_policy subscription_name, if different binding key or filter Source Durability) if noqueue consumerexists if has same exclusivity_policy rebind queue if different binding key or filter else if no consumer error(resource-locked) rebind queue else error(resource-locked)else else create_queue( error(resource-locked) queue_nameelse exclusivity_policy, error(resource-locked) else Source Durability, create_queue( Source Expiry Policy) queue_name bind queue exclusivity_policy, send Attach else queue_name = get_queue_name( Source Durability, Source Expiry Policy) name_space, bind queue send Attach subscription_name, else // name_space and subscription_name are derived as above just from Link capabilities instead of Source capabilities TRUE_DURABILITY) queue_name = get_queue_name( if queue exists if queue has consumers name_space, error(resource-locked) // This breaks the AMQP spec subscription_name, else TRUE_DURABILITY) delete queue if queue exists Attach Link with nullcorrect Source set else error(not-found) // This breaks the AMQP spec else queue_name = get_queue_name( name_space, subscription_name, TRUE_DURABILITY) if queue exists if has same exclusivity_policy if different binding key or filter if no consumer rebind queue else error(resource-locked) else error(resource-locked) else create_queue( queue_name exclusivity_policy, Source Durability, Source Expiry Policy) bind queue send Attach |