Installation guide

Chapter 10. Java Properties
10.1. Configuration Properties
The tables below enumerate the configuration properties available to an application server node. T he
location for these properties depends on how mod_cluster is configured.
10.1.1. Proxy Discovery Configurat ion
The list of proxies from which an application expects to receive AJP connections is either defined
statically, via the addresses defined in the proxyList configuration property; or discovered dynamically
via the advertise mechanism.
Using a special mod_advertise module, proxies can advertise their existence by periodically
broadcasting a multicast message containing its address/port.
This functionality is enabled via the advertise configuration property. If configured to listen, a server
can learn of the proxy's existence, then notify that proxy of its own existence, and update its
configuration accordingly. This frees both the proxy and the server from having to define static,
environment-specific configuration values.
Table 10.1. Proxy Discovery
Attribut e De fault De script ion
proxyList None Defines a comma-separated list of httpd proxies with
which this node will initially communicate. Value should
be of the form:
address1:port1,address2:port2
Using the default configuration, this property can by
manipulated via the jboss.modcluster.proxyList
system property.
excludedContexts ROOT ,admin-
console,invoker,jbossws,jmx-
console,juddi,web-console
List of contexts to exclude from htt pd registration, of
the form:
host1:context1,host2:context2,host3:context3
If no host is indicated, it is assumed to be the default
host of the server (e.g. localhost). "ROOT " indicates
the root context. Using the default configuration, this
property can by manipulated via the
jboss.modcluster.excludedContexts system
property.
autoEnableContexts True If false, the contexts are registered disabled in htt pd,
they need to be enabled via the enable() mbean
method or via mod_cluster_manager.
stopContextTimeout 10 The number of seconds to wait for clean shutdown of a
context,. This could be the completion of all pending
requests for a distributable context or the
destruction/expiration of active sessions for a non-
distributable context.
proxyURL None If defined, this value will be prepended to the URL of
MCMP commands.
socketTimeout 20000 Number of milliseconds to wait for a response from an
httpd proxy to MCMP commands before timing out and
flagging the proxy as in error.
advertise This is true if proxyList is
undefined, false otherwise.
If enabled, httpd proxies will be auto-discovered via
multicast announcements. This can be used either in
concert or in place of a static proxyList.
advertiseGroupAddress 224.0.1.105 The UDP address on which to listen for httpd proxy
multicast advertisements.
advertisePort 23364 The UDP port on which to listen for httpd proxy
multicast advertisements.
advertiseSecurityKey None If specified, httpd proxy advertisements checksums
will be verified using this value as a salt.
10.1.2. Proxy Configuration
The following configuration values are sent to proxies during server startup, when a proxy is detected
via the advertise mechanism, or during the resetting of a proxy's configuration during error recovery.
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