Transport configuration options
One of the first kinds of URI you are likely to use is a transport URI to connect to a broker using a kind of transport. Generally TCP or VM are the first transports you'll use.
The VM Transport
The VM transport allows clients to connect to each other inside the VM without the overhead of the network communication. The connection used is not that of a socket connection but instead uses direct method invocations to enable a high performance embedded messaging system.
The first client to use the VM connection will boot an embedded broker. Subsequent connections will attach that the same broker. Once all VM connections to the broker have been closed, the embedded broker will automatically shutdown.
For more information see the VM Transport Reference
The TCP Transport
The TCP transport allows clients to connect a remote ActiveMQ using a a TCP socket.
For more information see the TCP Transport Reference
The NIO Transport
To switch from TCP to NIO, simply change the scheme portion of the URI. Here's an example as defined within a broker's XML configuration file.
<broker> ... <transportConnectors> <transportConnector name="nio" uri="nio://0.0.0.0:61616"/> </<transportConnectors> ... </broker>
The SSL Transport
This allows you to talk over TCP using SSL.
For more information see the SSL Transport Reference
The NIO SSL Transport
Implementing SSL transport over NIO. This allows you to connect large number of SSL clients to a single broker instance. It's server side transport-option only
<broker> ... <transportConnectors> <transportConnector name="nio+ssl" uri="nio+ssl://0.0.0.0:61616"/> </<transportConnectors> ... </broker>
Trying to use nio+ssl transport url on the client side will instantiate the regular SSL transport.
The Peer Transport
The Peer transport provides a peer-to-peer network with ActiveMQ. What actually happens is the peer transport uses the VM transport to create and connect to a local embedded broker but which configures the embedded broker to establish network connections to other peer embedded brokers.
For more information see the Peer Transport Reference
The UDP Transport
This allows you to talk over UDP.
For more information see the UDP Transport Reference
The Multicast Transport
This allows you to talk over Multicast.
For more information see the Multicast Transport Reference
The HTTP and HTTPS Transport
For more information see the HTTP and HTTPs Transports Reference
The WebSockets Transport
This transport uses the new HTML5 WebSockets to exchange messages with the broker. For more information see the WebSockets Transport Reference
General Purpose URIs
You can configure other features via the URI syntax as follows...
Connection Configuration URI
For more information see Connection Configuration URI
You can configure various consumer related options using Destination Options which allow you to configure destinations using URI syntax.
Broker Configuration URI
You can use a Broker Configuration URI to configure an embedded broker, either using the BrokerFactory helper class from Java or using the activemq shell script. For more details see How to Run a Broker
Configuring Wire Formats
Any transport which involves marshalling messages onto some kind of network transport like TCP or UDP will typically use the OpenWire format. This is configurable to customize how things appear on the wire.
For more information see Configuring Wire Formats
High Level Protocol URIs
The following higher level protocols can be configured via URI
The Failover Transport
The Failover transport layers reconnect logic on top of any of the other transports. This is what used to be the Reliable transport in ActiveMQ 3. Its configuration syntax allows you to specify any number of composite URIs. The Failover transport randomly chooses one of the composite URIs and attempts to establish a connection to it. If it does not succeed or if it subsequently fails, a new connection is established to one of the other URIs in the list.
For more information see the Failover Transport Reference
The Fanout Transport
The Fanout transport layers reconnect and replicate logic on top of any of the other transports. It is used replicate commands to multiple brokers.
For more information see the Fanout Transport Reference
Often when using transports like TCP you want to use Discovery to locate the available brokers. This is different from using, say, Multicast - as the actual main communication is over TCP but multicast is purely used to discover the location of brokers.
The Discovery Transport
The Discovery transport works just like the reliable transport, except that it uses a discovery agent to locate the list of URIs to connect to.
For more information see the Discovery Transport Reference
The ZeroConf Transport
The ZeroConf transport provides Discovery and it works like the Discovery Transport but rather than using our own multicast based discovery mechanism (which allows you to configure the exact multicast address and port, etc.), the ZeroConf transport is used instead.
For more information see the ZeroConf Transport Reference
Server side options
There are a number of options that can be used for changing behaviour on the server for the TransportConnector in the ActiveMQ broker configuration. These are:
|uri||null||the bind address for the transport|
|name||null||the name of the TransportConnector instance|
|discoveryURI||null||if set, the multicast discovery address for client connections to find the broker|
|enableStatusMonitor||false||will monitor connections to determine if they are blocked|
|updateClusterClients||false||if enabled, will update client connections (if they use the failover:// transport) of changes to the broker cluster|
|rebalanceClusterClients||false||will automatically rebalance clients across the cluster on changes of topology|
|updateClusterClientsOnRemove||false||will update clients if a broker is removed from the cluster|
|updateClusterFilter||null||comma separated list of regular expressions. Brokers with the a name matching the pattern will be included for client updates|
~Note: properties in
are version 5.4 options only.~
An example configuration would be:
<broker> ... <transportConnectors> <transportConnector name="openwire" uri="tcp://0.0.0.0:61616" enableStatusMonitor="true"/> </<transportConnectors> ... </broker>