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https://issues.apache.org/jira/browse/DISPATCH-1337?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16843981#comment-16843981
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Gordon Sim commented on DISPATCH-1337:
--------------------------------------

What is the behaviour if both the `alternate` and `waypoint` are set to true? 
(Is that an allowed configuration?)

Does specifying the `qd.alternate` capability on a link require special 
permission? Can it only be requested on route-container connections?

> Alternate Destination for Unreachable Addresses
> -----------------------------------------------
>
>                 Key: DISPATCH-1337
>                 URL: https://issues.apache.org/jira/browse/DISPATCH-1337
>             Project: Qpid Dispatch
>          Issue Type: New Feature
>          Components: Router Node
>            Reporter: Ted Ross
>            Assignee: Ted Ross
>            Priority: Major
>             Fix For: 1.8.0
>
>
> This feature allows addresses to be configured such that an alternate 
> destination can be used to receive messages that are not deliverable to any 
> normal consumers on the address.
> Typically, this feature will be used to allow a message broker to store 
> messages that are not routable directly to consumers.  When one or more 
> consumers are attached in the router network, messages shall be delivered 
> directly to the consumers.  Where there are no reachable consumers, 
> deliveries shall then be diverted to the alternate destination.  Once 
> consumers re-connect to the network, messages shall again be delivered 
> directly.
> When a consumer comes online after messages have been stored in a broker, it 
> shall receive the stored messages interleaved with new messages from 
> producers.  No attempt shall be made by the router network to preserve the 
> original delivery order of the messages.
> This feature can be configured by adding the attribute
> {noformat}
>     alternate: yes
> {noformat}
> to an address configuration.  This attribute tells the router that any 
> address matching the configuration that appears shall support the alternate 
> destination capability.
> There are two ways to create an alternate destination for an address:
> Using auto-links:
> An auto-link (or a pair of auto-links) can be configured to create an 
> alternate waypoint for an address.  For example, assume that there is a 
> route-container connector or listener for a broker called "alternate-broker".
> {noformat}
> address {
>     prefix: position_update
>     alternate: yes
> }
> autoLink {
>     address: position_update.338
>     direction: in
>     connection: alternate-broker
>     alternate: yes
> }
> autoLink {
>     address: position_update.338
>     direction: out
>     connection: alternate-broker
>     alternate: yes
> }
> {noformat}
> The above configuration will use a queue on the broker called 
> "position_update.338" as the alternate destination for direct consumers.  
> Furthermore, since there are both _in_ and _out_ auto-links, the router(s) 
> shall send queued messages to newly attached direct consumers.
> Using terminus capabilities:
> As al alternative to using autl-links, the broker (or any other process) can 
> attach sending and receiving links to the address with terminus-capability 
> "qd.alternate".  This will create the same behavior as the above example.



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