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Chapter 6
Java Discovery Protocol (JDP)
The Java Discovery Protocol (JDP) is a protocol that enables technologies, in particular, Java Mission Control and Java Flight Recorder, to discover manageable JVMs across the same network subnet.
A manageable JVM is one that has the Java Management Extensions (JMX) agent running. JDP is multicast-based and works like a beacon; it broadcasts the JMX service URL (see the class JMXServiceURL) required to connect to the external JMX agent. This enables technologies to detect JVMs that have failed or are no longer available for monitoring.
Enabling and Configuring JDP
To enable JDP, specify the following option at the command line when starting a Java application:
-Dcom.sun.management.jmxremote.autodiscovery=true
Note - Enabling JDP does not affect JMX security. To enable and configure JMX security, see Chapter 2, Monitoring and Management Using JMX Technology.
The following table describes other properties that you may set to configure JDP:
| Property | Description | Default Value |
|---|---|---|
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Enables autodiscovery (JDP) on the network subnet |
false |
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Specifies the broadcast interval in seconds |
5 |
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Time-to-live in seconds for autodiscovery packets |
1 |
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Multicast address to send autodiscovery packets |
224.0.23.178 |
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Multicast port to send autodiscovery packets. Enables autodiscovery even if the
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7095 |
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Broadcast name of the JVM |
No default |
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Address of source interface to use for broadcast |
Automatically assigned |