# Using the Network Server with preexisting Derby applications

You must modify Java applications that currently run against Derby in embedded mode so that they work with the Derby Network Server.

The topics in this section discuss these changes.

- The Network Server and Java Virtual Machines (JVMs)
  The Derby Network Server is compatible with Java Platform, Standard Edition (Java SE) 17 and above.
- Installing required jar files and adding them to the classpath/modulepath
  To use the Network Server and network client driver, add the following jar file to your server classpath/modulepath.
- Starting the Network Server
  To start the Network Server, you can invoke a script, a jar file, or a class.
- Shutting down the Network Server
  To shut down the Network Server, you can invoke a script, a jar file, or a class.
- Obtaining system information
  You can obtain information about the Network Server, such as version and current property values, Java information, and Derby database server information, by using the sysinfo utility.
- Accessing the Network Server by using the network client driver
  When connecting to the Network Server, your application needs to load a driver and connection URL that are specific to the Network Server. In addition, you must specify a user name and password if you are using authentication.
- Accessing the Network Server by using a DataSource object
  The Network Server supports a set of Derby Network Client driver DataSource classes.
- XA and the Network Server
  Both the Derby embedded driver and the Network Server provide XA support. The Network Server provides DRDA level 7 support. DRDA clients that support XAMGR, such as the Derby network client, can send XA requests to the Network Server.
- Using the Derby tools with the Network Server
  The Derby tools ij and dblook work in embedded mode and client/server mode.
- Differences between running Derby in embedded mode and using the Network Server
  This section describes the differences between running Derby in embedded mode and using the Network Server.
- Setting port numbers
  By default, the Derby Network Server listens on TCP/IP port number 1527. If you want to use a different port number, you can specify it on the command line when starting the Network Server.

Parent topic: Part One: Derby Server Guide
Related concepts
Derby in a multi-user environment
Managing the Derby Network Server
Using Java Management Extensions (JMX) technology
Managing the Derby Network Server remotely by using the servlet interface
Derby Network Server advanced topics
Related reference
Derby Network Server sample programs