STOMP v1.1 Support
Probably the biggest change in ActiveMQ 5.6 is that we now support STOMP v1.1 but that's not the only thing we've done, there's plenty of new goodies even if you are stuck using a STOMP v1.0 based client. With the addition of STOMP 1.1 support STOMP you get:- protocol negotiation to allow for interoperability between clients and servers supporting successive versions of STOMP
- heartbeats to allow for reliable detection of disconnecting clients and servers
- NACK frames for negative acknowledgment of message receipt
- Support for virtual hosting.
Other New STOMP Features and Fixes
Of course support for STOMP 1.1 isn't the only thing we added to our STOMP support, there's several other new goodies in there as well. Lets take a look at what else you can now do with the STOMP Transport in ActiveMQ 5.6.Queue Browsing
A normal subscription on a queue will consume messages so that no other subscription will get a copy of the message. If you want to browse all the messages on a queue in a non-destructive fashion, you can create browsing subscription. To make a a browsing subscription, just add thebrowser:true header to the SUBSCRIBE frame. For example:SUBSCRIBE
id:mysub
browser:true
destination:/queue/foo
^@ browser:end header set.
Example:MESSAGE
subscription:mysub
destination:
message-id:
browser:end
^@ Message Selectors and Numeric Values
Prior to the 5.6 release you couldn't specify a numeric selector expression on a STOMP subscription, this has now been fixed so you are free to subscribe to a destination via STOMP using selectors such as the following:SUBSCRIBE
id:mysub
selector:someId = 42
destination:/queue/foo
^@ STOMP+NIO+SSL Transport
In 5.6 we've added NIO+SSL transports for both Openwire and STOMP clients which allow you to connect large numbers of SSL based STOMP clients to a single broker instance. You can configure a STOMP+NIO+SSL TransportConnector in you broker as follows:
transportconnector name="stomp+nio+ssl" uri="stomp+nio+ssl://0.0.0.0:61616"
STOMP 1.0 default heartbeat configuration
Unlike STOMP 1.1 the original STOMP 1.0 does not provide for an inactivity monitor since there was no defined hear-beat capability. A client connect that stays idle will remain active on the broker indefinitely. With STOMP 1.1, the inactivity monitor has come into play in response to theheart-beat
header. Since not all your clients might not be upgraded to STOMP 1.1 right away we added the capability to specify a default heart-beat value to the transportConnector so that you can still timeout idle STOMP connections. You can setup this default value on your connector as follows:stomp://0.0.0.0:0?transport.defaultHeartBeat=5000,0
In the absence of a heartbeat header, as in the STOMP 1.0 case, this default value would cause an InactivityMonitor with read check interval of 5 seconds to be installed on each new broker stomp transport connection. Any client that remains inactive (sends no messages) for more than 5 seconds will have their broker connection closed. You should tune this value based on the exceptions of the behavior of you clients.
