This topic describes how GemFire processes set their CLASSPATH.
To simplify CLASSPATH environment settings, GemFire has organized all application libraries required by GemFire processes into *-dependencies.jar files. All dependency JAR files are located in the path_to_product/lib directory.
When starting a server or locator process using gfsh, application JAR files are automatically loaded into the process’s CLASSPATH from two directories:
path_to_product/lib/path_to_product/extensions/Note: To embed GemFire in your application, add path_to_product/lib/gemfire-dependencies.jar to your CLASSPATH.
The following table lists the dependency JAR files associated with various GemFire processes:
| GemFire Process | Associated JAR Files |
|---|---|
| gfsh | gfsh-dependencies.jar |
| server and locator | gemfire-dependencies.jar
Note:
Use this library for all standalone or embedded GemFire processes (including Java clients) that host cache data. |
There are two options for updating the CLASSPATH of GemFire server and locator processes that are started on the gfsh command line.
Option 1: Specify the --classpath parameter upon process startup. For example, to modify the CLASSPATH of a locator:
gfsh> start locator --name=locator1 --classpath=/path/to/applications/classes.jar
And to modify the CLASSPATH of a server:
gfsh> start server --name=server1 --classpath=/path/to/applications/classes.jar
Application classes supplied as arguments to the --classpath option are loaded into the __automatic__ module if using classloader isolation or if classloader isolation is disabled, are prepended to the server or locator’s CLASSPATH, beginning in second position. The first entry in the CLASSPATH is reserved for the core GemFire jar file, for security reasons.
Option 2: Define the CLASSPATH environment variable in your OS environment. Then, specify the --include-system-classpath parameter upon process startup. For example:
gfsh> start locator --name=locator1 --include-system-classpath=true
The same can also be done for server processes:
gfsh> start server --name=server1 --include-system-classpath=true
If classloader isolation is disabled, this option appends the contents of the system CLASSPATH environment variable to the locator or server’s CLASSPATH upon startup. If classloader isolation is enabled, then this option is ignored. Specifying this option without a value sets it to true.
If you are starting a GemFire process programmatically (standalone or embedded), we recommend that you specify the CLASSPATH upon program execution using the java -classpath or java -cp command-line option. This method is preferred to setting the CLASSPATH as an environment variable since it allows you to set the value individually for each application without affecting other applications and without other applications modifying its value.
For example, to start up a GemFire locator process using the LocatorLauncher API, you can execute the following on the command line:
prompt# java -cp "path_to_product/lib/gemfire-dependencies.jar"
org.apache.geode.distributed.LocatorLauncher start locator1
<locator-launcher-options>
To start up a GemFire server process using the ServerLauncher API:
prompt# java -cp "path_to_product/lib/gemfire-dependencies.jar:/path/to/your/applications/classes.jar"
org.apache.geode.distributed.ServerLauncher start server1
<server-launcher-options>
Note that in addition to the *-dependencies.jar file associated with the process, you must also specify any custom application JARs that you wish to access in your GemFire process. For example, if you are planning on using a customized compressor on your regions, you should specify the application JAR that contains the compressor application you wish to use.
To start up an application with an embedded cache:
java -cp "path_to_product/lib/gemfire-dependencies.jar:/path/to/your/applications/classes.jar"
com.mycompany.package.ApplicationWithEmbeddedCache
Note: Another method for updating the CLASSPATH of a server process with your own applications is to use the gfsh deploy command. Deploying application JAR files will automatically update the CLASSPATH of all members that are targeted for deployment. See Deploying Application JARs to VMware GemFire Members for more details.
Note: Members started with classloader isolation will not automatically reload deployed JAR files from disk on restart. If enabled, JAR files from cluster configuration will still be deployed automatically.
For systems running an embedded HTTP or HTTPS service, setting a GEMFIRE_HOME environment variable with a path to the GemFire installation directory allows a server launcher to find the WAR file without any changes to the CLASSPATH.
