Apache ActiveMQ ™ -- Configuring Transports
Using ActiveMQ > Configuring Transports
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.
Be careful about whitespace
All of the following URI configurations are based on the java.net.URI class which does not allow whitespace to be used. So if you are using failover: or static: URIs, do not put any whitespace around the ',' symbol.
The AUTO Transport
Starting with 5.13.0 ActiveMQ has support for automatic wire protocol detection over TCP, SSL, NIO, and NIO SSL. OpenWire, STOMP, AMQP, and MQTT are supported. For details see the AUTO Transport Reference.
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 AMQP Transport
As of 5.8.0 ActiveMQ has support for AMQP. For details see the AMQP Transport Reference.
The MQTT Transport
Starting with 5.6.0 ActiveMQ also supports MQTT. Its a light weight publish/subscribe messaging transport. See the MQTT Transport Reference for details.
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
Same as the TCP transport, except that the New I/O (NIO) package is used, which may provide better performance. The Java NIO package should not be confused with IBM's AIO4J package.
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.
Trying to use nio transport url on the client side will instantiate the regular TCP transport. For more information see the NIO Transport Reference
The SSL Transport
This allows you to talk over TCP using SSL. For more information see the SSL Transport Reference
The NIO SSL Transport
Availability
Available since 5.6
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
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
This allows the ActiveMQ client and broker to tunnel over HTTP. If the client is not JMS you might want to look at REST or Ajax support instead.
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
The Stomp Transport
A plain text transport that can be used with many languages. See Stomp for more details.
General Purpose URIs
You can configure other features via the URI syntax as follows...
Connection Configuration URI
Any Apache ActiveMQ JMS connection can be configured using the URL or explicitly setting properties on the ActiveMQConnection or ActiveMQConnectionFactory objects themselves.
For more information see Connection Configuration URI
Destination Options
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
Using Discovery
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 behavior on the server for the TransportConnector in the ActiveMQ broker configuration. These are:
property name
default
description
allowLinkStealing
false
This is enabled for default for MQTT transport.
Link Stealing is where the last of two or more connections with the same id (clientID for JMS) is deemed the valid connection and the older one is closed by the broker.
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.
name
null
The name of the TransportConnector instance.
rebalanceClusterClients
false
Will automatically re-balance clients across the cluster on changes of topology.
updateClusterClients
false
If enabled, will update client connections (if they use the failover:// transport) of changes to the broker cluster.
updateClusterClientsOnRemove
false
Will update clients if a broker is removed from the cluster.
updateClusterFilter
null
Comma separated list of regular expressions. Brokers with a name matching the pattern will be included for client updates.
uri
null
The bind address for the transport.
Note: properties in red are version 5.10 (and higher) options only.
Example configuration: