DO NOT modify any of these parameters unless you have read this property description.
Incorrect settings can cause the Wrapper to fail to operate as expected.
The Wrapper uses a socket to communicate with its Java component running inside a JVM.
This property allows the configuration of this port.
When a port of "0" (zero) is specified,
the Wrapper will treat this as if the property has not been specified.
Most applications will not need to specify this property as the default value of "0" (zero),
which instructs the Wrapper to choose its own port within the range of
wrapper.port.max properties, which will be sufficient.
If the port specified by this property couldn't be bound
because the port is already being used, or hasn't been specified,
then the Wrapper will be using the range of
wrapper.port.max properties to bind a port.
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.
Controlling the port range.
"wrapper.port.min" and "wrapper.port.max":
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 numbers
(from 0 to 1023 generally assigned on most systems).
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.
Controlling the address the port will be bound to.
With this property, it is possible to specify the interface to
which the port(s), for communication of the Wrapper with the
JVM, should be bound to. Each machines provides several virtual
and physical network interfaces, to which a port can be bound.
Before this property has been introduced, the Wrapper was always
using the loopback interface (localhost, 127.0.0.1)
for binding a port, if a socket was used for the backend
It has been observed that on some machines a very strict security
policy is potentially not allowing binding a port to the local
loopback interface. This rendered the socket backend communication
as not usable and as work around the PIPE
backend type had to be used.
The property value is a IP address of an available interface on
the server. The default value
for this property is the IP address
of the loopback interface, i.e. 127.0.0.1.