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# 2 Specific Issues

This chapter lists problems that you might encounter when using Oracle GlassFish Server 3.1.2. The following topics are addressed:

- Cannot Access Local Server (`http://localhost:8080`)

- Cannot Access Remote Server

- Cannot Access the Administration Console

- Cannot Access a Server Application

- Administrator User Name or Password Not Known

- Experience Issues Related to the JDK

- Server Will Not Start on Windows (Port Conflict)

- Two Server Instances Bind to Same Port on Windows

- Cannot Produce a JVM Thread Dump After Server Crash

- Issues Related to Applications

- Issues Related to `asadmin`

- Issues Related to Installation

- Issues Related to Security

## Cannot Access Local Server (`http://localhost:8080`)

When this error occurs, check the following:

- Did the Server Start?

- Was the Server Started at the Expected Port?

- Is a Personal Firewall Enabled?

### Did the Server Start?

#### Description

If the console window is still open, the expected message indicates that the default domain was started successfully.

If the console window is already closed, check for messages in the log file. This is the default location:

    domain-dir/logs/server.log

If startup was successful, the expected message is similar to that on the console, and appears at the end of the log file.

For more information about starting a domain, see "Starting and Stopping a Domain" in Oracle GlassFish Server Administration Guide. To easily determine if a domain is running, use the `asadmin list-domains` command.

### Was the Server Started at the Expected Port?

#### Description

The server might be running at a different port number than expected, either because it was intentionally installed there, or because another server was already running on the default port when the server was installed.

##### To Determine Which Port Number the Server Is Using

Follow this procedure.

1. Examine the server's configuration file:

       domain-dir/config/domain.xml

2. Find the `network-listener` element.

3. Inspect the value of the `port` attribute.

   Be sure to enter the correct port number when invoking the server.

   Note:

   The server's default port number is `8080`, however, there are a number of ways in which the expected value can change:

   - A different port number was specified during installation.

   - A previous installation exists.

### Is a Personal Firewall Enabled?

Issues might result when personal firewalls are enabled. Disable your personal firewall and see if the server access problem still exists.

## Cannot Access Remote Server

When attempting to open the start page of GlassFish Server, the initial screen does not appear.

When this error occurs, check the following:

- Is the Server Available Locally?

- Is the Proxy Setting Causing a Problem?

### Is the Server Available Locally?

#### Description

If the server cannot be accessed from the web, but it is running locally, then the server is actually running.

#### Solution

Verify that the server is running locally.

##### To Verify That the Server Is Running Locally

Follow this procedure.

1. Log on to the host where the server is running.

2. Go to the local web page. For example, if `8080` is the default port, go to:

       http://localhost:8080/

   If the start page does appear, the web connection is encountering a problem that prevents accessing the server remotely. If the start page does not appear, see Did the Server Start?.

### Is the Proxy Setting Causing a Problem?

#### Description

The server should be accessible directly from the host on which it is running (`localhost`); for example, using the default port `8080`:

    http://localhost:8080/

#### Solution

A server instance running on `localhost` might not be accessible if the server host machine is connected to the web through a proxy. To solve this problem, do one of the following:

- Set the browser to bypass the proxy server when accessing `localhost`. Refer to the browser's help system for information about how to do this.

- Use the fully-qualified host name or IP address of your system; for example:

      http://myhost.mydomain.com:8080/

- Create an entry in the system's hosts file (for example, pointing `127.0.0.1` to `localhost`; `127.0.0.1` is not proxied).

Note:

To determine the host name for the `localhost` machine, type `hostname` at the command prompt.

## Cannot Access the Administration Console

The Administration Console provides a graphical interface for administrative functions. If the Administration Console is not accessible, check the following:

- Is the Application Server Running?

- Is the Administration Console Running on the Expected Port?

For more information about the Administration Console, see "Administration Console" in Oracle GlassFish Server Administration Guide.

### Is the Application Server Running?

#### Description

The server must be running before the Administration Console can be accessed.

#### Solution

Review the information in Did the Server Start? to determine if the server is running.

### Is the Administration Console Running on the Expected Port?

#### Description

The default port number for the Administration Console is `4848`. However, it could be running on a different port number than expected, either because it was intentionally installed there, or because that port was in use when the server was started.

#### Solution

Refer to Was the Server Started at the Expected Port? for guidelines on verifying the port on which the Administration Console is running. Be sure to enter the correct port number and HTTP protocol when invoking the Administration Console.

## Cannot Access a Server Application

If a particular application cannot be accessed through GlassFish Server, check the following:

- Is the Application Server Running?

- Was Application Deployment Successful?

### Is the Application Server Running?

#### Description

If GlassFish Server is not running, applications are not accessible.

#### Solution

Review the information in Did the Server Start? to determine if the server is running. The server must be running before a server application can be accessed.

### Was Application Deployment Successful?

#### Description

An application must be successfully deployed before it can be accessed.

#### Solution

Verify that the application was successfully deployed. There are several ways to do this:

- Check the server's log file for related entries:

      domain-dir/server.log

- Use the `asadmin list-applications` command to determine which applications are deployed.

- View the Applications page in the Administration Console, accessed by clicking the Applications node.

For more information about deploying applications, see "Deploying Applications" in Oracle GlassFish Server Application Deployment Guide. Also see the Administration Console online help.

## Administrator User Name or Password Not Known

If you have forgotten the administrator user name, you can find it by inspecting the domain-dir`/config/admin-keyfile` file, where domain-dir is the directory for the domain. In the default domain, `domain1`, the file to inspect is domain-dir`/config/admin-keyfile`. For a different domain, substitute its name in the path.

If you have forgotten the administrator password, one solution is to create a new domain with the admin username and password that you want, then copy the entry from the `config/admin-keyfile` file in that new domain to the other domain.

## Experience Issues Related to the JDK

### Description

You experience JDK-related issues in a variety of circumstances.

### Solution

GlassFish Server 3.1.2 requires JDK 6, so check your system for that dependency.

The minimum (and certified) version of the JDK software that is required for GlassFish Server depends on the operating system:

- For supported operating systems except Mac OS, the minimum required version is 1.6.0_17.

- For the Mac OS X operating system, the minimum required version is 1.6.0_15.

Ensure that the required JDK software is installed and that the `JAVA_HOME` environment variable points to the JDK installation directory, not the Java Runtime Environment (JRE) software.

Set `JAVA_HOME` and `$JAVA_HOME/bin` in the `PATH` to point to the supported JDK version.

## Server Will Not Start on Windows (Port Conflict)

If a message similar to the following is displayed when starting GlassFish Server on Microsoft Windows, a server port conflict has occurred:

    Address already in use

This error occurs when another application is running on the GlassFish Server port (default `8080`), or because a previous instance of GlassFish Server did not shut down cleanly.

You might also check the following:

- Is Another Application Running on the Server's Port?

- Has an Ungraceful Shutdown Occurred on a Previously Running Server?

### Is Another Application Running on the Server's Port?

If another application is using the server's port, stop the other application, then restart GlassFish Server.

### Has an Ungraceful Shutdown Occurred on a Previously Running Server?

Use the `asadmin stop-domain` command to stop the server, or explicitly kill the Java process and then restart GlassFish Server.

## Two Server Instances Bind to Same Port on Windows

### Description

This problem occurs on Windows XP systems with GlassFish Server software, and is due to a known Windows security flaw rather than a problem with GlassFish Server itself.

The problem occurs when two or more instances of GlassFish Server are created using the same port number for the `instanceport` option; for example:

    asadmin create-domain -adminport 5001 options -instanceport 6001 domain
    asadmin create-domain -adminport 5002 options -instanceport 6001 domain

When the two domains are started on a UNIX or Linux system, a port conflict error is thrown and the second instance fails to start. However, when the two domains are started on Windows XP, no error is thrown, both server instances start, but only the first instance is accessible at the specified port. When that first server instance is subsequently shut down, the second instance then becomes accessible. Moreover, when both instances are running, the Windows `netstat` command only reports the first instance.

### Solution

Be sure to use unique port numbers for all server instances on Windows systems.

## Cannot Produce a JVM Thread Dump After Server Crash

### Description

If GlassFish Server crashes, the server dumps a core file and, by default, restarts with the `-Xrs` flag, which prevents the dump of a JVM thread dump.

### Solution

#### To Obtain a Server Thread Dump

Type the following command:

    asadmin generate-jvm-report --type=thread

See Also

`generate-jvm-report`(1)

## Issues Related to Applications

### Cannot Undeploy or Redeploy Application With Open Streams to `jar` Files (Windows)

#### Description

On Windows systems, after running an application, subsequent attempts to undeploy it or redeploy it throw exceptions about the server being unable to delete a file or rename a directory.

On Windows systems, an application may use `getClass().getResource` or `getResourceAsStream` methods to locate a resource inside the application, particularly in `jar` files that are in the application or accessible to it. If the streams remain open, subsequent attempts to redeploy or undeploy the application can fail. In addition, the Java runtime by default caches streams to `jar` files for performance reasons.

#### Solution

Be sure to close streams opened by your applications. Also, if an application needs to be redeployed or undeployed repeatedly, and also needs to obtain a resource from a `jar` file using `getResource` or `getResourceAsStream`, consider using `getClass().getResource`, which returns a URL object, then invoke the `url.setUseCaches` method to turn off caching for that `jar` file, and use `url.getInputStream()` to obtain the stream.

Although turning off caching for access to the `jar` file can slow performance, this approach does allow the application to be undeployed or redeployed. Note also that if the `getClass().getResourceAsStream` method is used instead, then the `jar` file in which the resource is located is cached (this is the default Java runtime setting) and remains open until the server is stopped.

### `MaxPermGen` Exception

#### Description

Application servers such as GlassFish Server allow you to redeploy an application without restarting the server. Simply make the change in your source code, compile the source, and redeploy the application.

Each application is loaded using its own classloader. When you undeploy an application, its classloader is discarded with all the classes it loaded and is garbage collected sooner or later. However, if there's a reference from outside an application to an object in the application loaded by the application's classloader, that object can't be garbage collected. The reference holds the object in memory.

The memory in the Virtual Machine is divided into a number of regions. One of these regions is `PermGen`. It's an area of memory used to (among other things) load class files. The size of this memory region is fixed; it does not change when the VM is running. You can specify the size of this region with a command line switch: `-XX:MaxPermSize`. Setting the `-Xmx` parameter does not help: this parameter only specifies the total heap size and does not affect the size of the `PermGen` region.

If you keep loading new classes that can't be garbage collected because of references to them from outside the application, the VM runs out of space in the `PermGen` region, even if there's plenty of memory available. This is called a classloader leak. The resulting exception is `java.lang.OutOfMemoryError: PermGen space`.

The `java.lang.String.intern()` method also allocates memory in the `PermGen` region. If your application uses this method with strings and holds references to these strings, thereby making garbage collection impossible, your application may cause the same `PermGen space` exception.

#### Solution

Classloader leaks are difficult to diagnose. Most profilers list leaked objects but don't highlight the ones causing classloader leaks. Most profilers also stop tracing as soon as they reach a class object or classloader.

One diagnostic approach involves undeploying the application and triggering a memory dump using the JDK 6.0 `jmap` tool. Then you can use the JDK 6.0 `jhat` tool to analyze the dump. The simplest analysis is to list all instances of `java.lang.Class` and look for class objects that have many instances. This is a sign that the class has been loaded multiple times without being garbage collected.

If you're willing to modify the `jhat` code, you can perform more refined queries. For example:

- Trace references to a classloader from all the instances of the classes it loaded.

- Generate a list of all classloader instances that have loaded an identical set of classes.

- Find classloader instances whose only strong-reference chains from the root set go through instances of classes loaded by those classloaders. These are called orphaned classloaders.

To override the original `jhat` code, put the JAR file of the modified `jhat` code in the `lib/ext` directory of the JDK.

## Issues Related to `asadmin`

### `asadmin` `start-domain` Command Fails

The command `asadmin start-domain` fails with the following error:

    There is more than one domain...

#### Description

When issued with no arguments, the command `asadmin start-domain` fails.

This error occurs when there is more than one domain in the domains directory, none of them is named `domain1,` and no domain is specified with the `start-domain` command.

#### Solution

Specify the domain when issuing the `start-domain` command:

    asadmin start-domain domain-name

For example:

    asadmin start-domain mycustomdomain

### Cannot Stop Domain Using `asadmin` `stop-domain`

#### Description

You cannot stop the domain using the `asadmin` `stop-domain` command.

#### Solution

Look for error messages that display in the console when you issue the command.

Search the `server.log` file for error messages related to your inability to stop the domain.

## Issues Related to Installation

### Installation Hangs During Update Tool Configuration

#### Description

Installation hangs more than five minutes during Update Tool configuration.

#### Solution

Cancel the installation and run the installation program again, but this time deselect the Install Update Tool check box. Update Tool can be installed later from as-install`/bin/`. For more information about Update Tool, see "Update Tool" in Oracle GlassFish Server Administration Guide. For general information about GlassFish Serverinstallation, see the Oracle GlassFish Server Installation Guide.

Note:

Update Tool differs from Upgrade Tool, which is used to migrate the configuration and deployed applications from an earlier version of GlassFish Server to the current version. For more information about Upgrade Tool and upgrading, see the Oracle GlassFish Server Upgrade Guide.

### GlassFish Server Components Not Removed During Uninstallation

#### Description

Not all GlassFish Server directories are automatically removed by the uninstallation program. Some directories and files remain after uninstalling.

#### Solution

Examine the remaining directories and remove any files or directories that you do not want, including hidden directories prefixed with a dot. It is safe to remove uninstallation and installation log files after you have examined them.

For information related to uninstallation, see "Uninstalling GlassFish Server 3.1" in Oracle GlassFish Server Installation Guide.

## Issues Related to Security

### `java.security.AccessControlException`: Access Denied Error

#### Description

The following error occurs from an application client, or appears in the `server.log` file:

    java.security.AccessControlException: access denied
    (java.util.PropertyPermission name write...)

There is a permissions issue in the policy files. Either the `client.policy` file for the application client or the `server.policy` file for server side components does not have permission to set the property.

#### Solution

Add the permission in `client.policy` (for the application client), or in `server.policy` (for web modules) for the application that needs to set the property. By default, applications only have read permission for properties.

For example, to grant read/write permission for all files in the codebase directory, add or append the following to `client.policy` or `server.policy`:

    grant codeBase "file:/.../build/sparc_SunOS/sec/-" {
       permission java.util.PropertyPermission "*", "read,write";
     };

### Mutual Authentication Not Working With the Application Client

#### Description

This failure can occur when the keystore and truststore properties are not set properly.

#### Solution

Set the following properties on the JVM:

    javax.net.ssl.keyStore=
    <keystore-file-path>;javax.net.ssl.trustStore=<truststore-file-path>

To use the application client, set the environment variable `VMARGS` to the following value:

    -Djavax.net.ssl.keyStore=${admin.domain.dir}/${admin.domain}/config/keystore.jks
    -Djavax.net.ssl.trustStore=${admin.domain.dir}/${admin.domain}/config/cacerts.jks