The Wrapper uses a socket to communicate with its Java component running
inside a JVM. This property allows the configuration of this port. Most
applications need not specify this property as the default value of 0,
which instructs the Wrapper to choose its own port, will be sufficient.
When a port of 0 is specified, the Wrapper will search for the first
available port starting with port number 32000. If a valid port can
not be found within the first 1000 attempts then the Wrapper will fail
with an error. To my knowledge, this has never been seen. This means
that auto allocated ports will fall in the range 32000-32999.
If a specific port should be used, then any port in the range 1-65535 may
be specified. Note that on UNIX systems port numbers below 1024 will most
likely require root access to be set. If the specified port is in use then
the Wrapper will display a warning to the log and, as with the default
case, will search for the first available port.
When the Wrapper launches a JVM instance, it will open a server
socket listening on this port bound to the localhost address. The
launched JVM will be supplied with a key which it must use to be
able to connect back to the Wrapper process. Once the JVM has
connected, the Wrapper will no longer accept additional connections.
The way this is done should not raise any security issues.
Example: |
wrapper.port=1777
|
 |
 |
In some cases, it is necessary to control the range of ports that
the Wrapper will use when choosing a port. The defaults were chosen
to make it very unlikely that they would conflict with any well known
ports. If the default 32000-32999 range is causing problems, it can
be changed using the wrapper.port.min
and wrapper.port.max properties.
If these are used, be sure to provide a large enough range to make it
unlikely that all of the ports will be in use when the Wrapper attempts
to start.
Example: |
wrapper.port.min=32000
wrapper.port.max=32999
|
|
|