Configuring Wire Formats

Using ActiveMQ Classic > Configuring Transports > ActiveMQ Classic Connection URIs > Configuring Wire Format

The OpenWire Wire Format

OpenWire is the default wire format used by ActiveMQ Classic.  It provides a highly efficient binary format for high speed messaging.  OpenWire options can be configured on a JMS client’s connection URI or on a broker’s transport bind URI.

Option Default Description
cacheEnabled true Should commonly repeated values be cached so that less marshaling occurs?
cacheSize 1024 When cacheEnabled=true then this parameter is used to specify the number of values to be cached.
maxInactivityDuration 30000 The maximum inactivity duration (before which the socket is considered dead) in milliseconds. On some platforms it can take a long time for a socket to die. Therefore allow the broker to kill connections when they have been inactive for the configured period of time. Used by some transports to enable a keep alive heart beat feature. Inactivity monitoring is disabled when set to a value <= 0.
maxInactivityDurationInitalDelay 10000 The initial delay before starting inactivity checks. Yes, the word 'Inital' is supposed to be misspelled like that.
maxFrameSize MAX_LONG Maximum allowed frame size. Can help help prevent OOM DOS attacks.
maxFrameSizeEnabled true Should the maxFrameSize check be verified? (since: v5.16.4)
sizePrefixDisabled false Should the size of the packet be prefixed before each packet is marshaled?
stackTraceEnabled true Should the stack trace of exception that occur on the broker be sent to the client?
tcpNoDelayEnabled true Does not affect the wire format, but provides a hint to the peer that TCP_NODELAY should be enabled on the communications Socket.
tightEncodingEnabled true Should wire size be optimized over CPU usage?

Use the Correct Prefix!

Wire format options must have the prefix wireFormat. to take effect, e.g., wireFormat.maxInactivityDuration=10000. Options missing this prefix will be ignored.

Example Configurations


ActiveMQConnectionFactory cf = new ActiveMQConnectionFactory("tcp://localhost:61616?wireFormat.cacheEnabled=false&wireFormat.tightEncodingEnabled=false");


<bean class="org.apache.activemq.ActiveMQConnectionFactory">
  <property name="brokerURL" value="failover:(tcp://localhost:61616?jms.optimizeAcknowledge=false&wireFormat.maxInactivityDuration=30000)"/>
  <!-- other options... -->

Max Frame Size:

The maxFrameSizeEnabled check applies to both the client and server-side. The setting is not transferred from the server to the client during wireformat negotiation. This allows clients and servers to configure independently (generally only for testing).

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