Hosted by:

wrapper.port Property

wrapper.port Property

Configuration Property Overview

- Configuration Property Overview
- Advanced Properties
- Property List by Name

wrapper.port

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

| Controlling the port range.

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

by Leif Mortenson

Copyright ©1999-2004 by Tanuki Software. All Rights Reserved. | last modified: