Skip Headers

Oracle® Application Server Administrator's Guide 10g Release 3 (10.1.3) B25209-01 |
| Home | Solution Area | Contents | Index

Previous | Next |

# H Troubleshooting Oracle Application Server

This appendix provides information on how to troubleshoot problems that you might encounter when using Oracle Application Server. It contains the following topics:

- Diagnosing Oracle Application Server Problems

- Common Problems and Solutions

- Troubleshooting Application Server Control

- Need More Help?

See Also: Chapter 14, "Troubleshooting SSL" for information about troubleshooting SSL. Chapter 19, "Troubleshooting OracleAS Recovery Manager" for specific information about troubleshooting the OracleAS Recovery Manager.

## H.1 Diagnosing Oracle Application Server Problems

Oracle Application Server components generate log files containing messages that record all types of events, including startup and shutdown information, errors, warning messages, access information on HTTP requests, and additional information. The log files can be used to identify and diagnose problems. See Chapter 5, "Managing Log Files" for more information about using and reading log files.

## H.2 Common Problems and Solutions

This section describes common problems and solutions. It contains the following topics:

- Application Performance Impacted by Garbage Collection Pauses

- Application Server Returns Connection Refused Errors

- Oracle HTTP Server Unable to Start Due to Port Conflict

- Machine Overloaded by Number of HTTPD Processes

- Oracle Application Server Process Does Not Start

- OPMN Start Up Consumes CPU Processing Capability

- Browser Displaying a Page Not Displayed Error

- Standby Site Not Synchronized

- Failure to Bring Up Standby Instances After Failover or Switchover

- Previously Working Application Using ADF Business Components Starts Throwing JDBC Errors

### H.2.1 Application Performance Impacted by Garbage Collection Pauses

Application performance slows or application is unresponsive.

See the section "Application Performance Impacted by Garbage Collection Pauses" in the Oracle Containers for J2EE Configuration and Administration Guide for information about the causes and solutions to this problem.

### H.2.2 Application Server Returns Connection Refused Errors

In load conditions (for example, when the number of users concurrently connecting to the application server increases significantly in a short time), the server may respond with the following error message:

    IOException in sending request - Connection refused

Problem

If the number of simultaneous users is increasing, the server may be utilizing the maximum Oracle HTTP Server child processes allowable to service requests.

Solution

You may need to increase the MaxClients directive for the Oracle HTTP Server. The MaxClients directive specifies a limit on the number of clients who can simultaneously connect.

Use one of the following methods to determine if this is the case:

- Search the Oracle HTTP Server error log file for the following message:

      server reached MaxClients setting, consider raising the MaxClients setting

  By default, the error log file is located in:

      (UNIX) ORACLE_HOME/Apache/Apache/logs/error_log
      (Windows) ORACLE_HOME\Apache\Apache\logs\error_log

- Interactively monitor child process activity using the metrics in the Application Server Control Console. In particular, view the following in the HTTP_Server Home page:

  - In the Status section, Active Connections, which shows the number of clients currently executing HTTP requests.

  - In the Response and Load section, Active Requests, which shows the total number of active requests currently being processed.

- Look at the information provided by mod_status. The mod_status module provides an HTML page that shows the current server statistics. Check to see if the all the processes are busy. (By default, Mod_status is enabled for localhost access only.) For more information on mod_status, see:

  `http://httpd.apache.org/docs/mod/mod_status.html`

In addition, consider increasing the maximum queue length for pending connections (the ListenBackLog directive) and consider the impact of persistent connections (the KeepAlive directive).

For more information about theOracle HTTP Server directives and how to change their values, see the Oracle HTTP Server Administrator's Guide. For more information about tuning Oracle HTTP Server processes, see the Oracle Application Server Performance Guide.

### H.2.3 Oracle HTTP Server Unable to Start Due to Port Conflict

You can get the following error if Oracle HTTP Server is unable to start due to port conflict:

    [crit] (98) Address already in use: make_sock: could not bind to port 7778

See the section "Oracle HTTP Server Unable to Start Due to Port Conflict" in the Troubleshooting Oracle HTTP Server appendix of the Oracle HTTP Server Administrator's Guide for information about the cause and solution to this problem.

### H.2.4 Machine Overloaded by Number of HTTPD Processes

When there are too many httpd processes running on a machine, the response time plummets.

See the section "Machine Overloaded by Number of HTTPD Processes" in the Troubleshooting Oracle HTTP Server appendix of the Oracle HTTP Server Administrator's Guide for information about the cause and solution to this problem.

### H.2.5 Oracle Application Server Process Does Not Start

You are not able to start an Oracle Application Server process using OPMN.

See Section A.1.1, "Oracle Application Server Process Does Not Start" in the Oracle Process Manager and Notification Server Administrator's Guide for information about the causes and solutions to this problem.

### H.2.6 OPMN Start Up Consumes CPU Processing Capability

On some computers, when OPMN starts up, it consumes large amounts of CPU processing capability.

See Section A.1.15, "OPMN Start Up Consumes CPU Processing Capability" in the Oracle Process Manager and Notification Server Administrator's Guide for information about the causes and solutions to this problem.

### H.2.7 Browser Displaying a Page Not Displayed Error

Browsers return an error saying that a page cannot be displayed.

If you use OracleAS Web Cache, Release 2 (10.1.2), as a reverse proxy, see Section E.1.7, "Browser Displaying a Page Not Displayed Error" in the Oracle Application Server Web Cache Administrator's Guide for the release for information about the causes and solutions to this problem.

### H.2.8 Standby Site Not Synchronized

In the OracleAS Disaster Recovery standby site, you may find that the site's OracleAS Metadata Repository is not synchronized with the OracleAS Metadata Repository in the primary site.

See Section A.3.1, "Standby Site Not Synchronized" in the Oracle Application Server High Availability Guide for information about the causes and solutions to this problem.

### H.2.9 Failure to Bring Up Standby Instances After Failover or Switchover

Standby instances are not started after a failover or switchover operation.

See Section A.3.2, "Failure to Bring Up Standby Instances After Failover or Switchover" in the Oracle Application Server High Availability Guide for information about the causes and solutions to this problem.

### H.2.10 Previously Working Application Using ADF Business Components Starts Throwing JDBC Errors

An application that previously successfully retrieved data suddenly starts throwing JDBC errors such as Connection Reset By Peer, Connection Closed, or Socket Reset By Peer.

See the section "Previously Working Application Using ADF Business Components Starts Throwing JDBC Errors" in the Oracle Application Development Framework Developer's Guide for information about the causes and solutions to this problem.

## H.3 Troubleshooting Application Server Control

The following sections describe problems and issues when using the 10g Release 3 (10.1.3) Application Server Control:

- Resetting the Administrator (oc4jadmin) Password

- Deployment Performance in Internet Explorer 6.0 and Netscape Navigator 7.0

- Troubleshooting OC4J Out-of-Memory Errors

- "403 Forbidden - Directory browsing not allowed" Error When Testing a Web Module or Web Service

- Administrator Credentials Error When Attempting to Access the OC4J Home Page in a Cluster Topology

### H.3.1 Resetting the Administrator (oc4jadmin) Password

To manage an instance of Oracle Application Server, you must log in to the Application Server Control Console using the current Administrator (`oc4jadmin`) password.

Problem

If you forget or do not know the `oc4jadmin` password, then you cannot monitor or administer the application server or its components with the Application Server Control Console.

Solution

Reset the `oc4jadmin` password using the following procedure while you are logged in as the user who installed the Oracle Application Server instance:

1. Stop OC4J and the Application Server Control.

   Enter the following command in the Oracle home of the application server instance:

       (UNIX) ORACLE_HOME/opmn/bin/opmnctl stopproc ias-component=OC4J
       (Windows) ORACLE_HOME\opmn\bin\opmnctl stopproc ias-component=OC4J

2. Locate and open the following file in a text editor:

       (UNIX)ORACLE_HOME/j2ee/home/config/system-jazn-data.xml
       (Windows)ORACLE_HOME\j2ee\home\config\system-jazn-data.xml

3. Locate the line that defines the credentials property for the oc4j`admin` user.

   The following example shows the section of `system-jazn-data.xml` with the encrypted `credentials` entry in boldface type:

       <jazn-realm>
          <realm>
             <name>jazn.com</name>
             <users>
              .
              .
              .
                <user>
                   <name>oc4jadmin</name>
                   <display-name>OC4J Administrator</display-name>
                   <description>OC4J Administrator</description>
                   <credentials>{903}4L50lHJWIFGwLgHXTub7eYK9e0AnWLUH</credentials>
                </user>

4. Replace the existing encrypted password with the new password.

   Be sure to prefix the password with an exclamation point (!). For example:

       <credentials>!mynewpassword123</credentials>

   The password for the `oc4jadmin` user should conform to following guidelines:

   - Must contain at least five characters, but not more than 30 characters.

   - Must begin with an alphabetic character. It cannot begin with a number, the underscore (_), the dollar sign ($), or the number sign (#).

   - At least one of the characters must be a number.

   - Can contain only the following characters; numbers, letters, and the following special characters: US dollar sign ($), number sign (#), or underscore (_).

   - Cannot contain any Oracle reserved words, such as VARCHAR.

   See Also: "The oc4jadmin User and Restrictions on its Password" in the Oracle Application Server Installation Guide

5. Start OC4J and the Application Server Control.

   After the restart, the Application Server Control will use your new Administrator (`oc4jadmin`) password, which will be stored in encrypted format within the `system-jazn-data.xml` file.

   See Also: Section A.1, "Starting and Stopping Application Server Control"

### H.3.2 Deployment Performance in Internet Explorer 6.0 and Netscape Navigator 7.0

Problem

If you attempt to deploy an OC4J application while using Microsoft Internet Explorer 6.0 or Netscape 7.0, the file upload may take an extremely long time (for example, 10 minutes for a 45 MB `.ear` file as compared to 15 seconds with Netscape 7.1).

Solution

If you are using Netscape Navigator, upgrade to Netscape 7.1.

If you are using Internet Explorer, refer to the following Microsoft knowledge base article, which addresses this problem:

    http://support.microsoft.com/default.aspx?scid=kb;en-us;329781

### H.3.3 Troubleshooting OC4J Out-of-Memory Errors

Problem

Depending upon the size and number of applications you deploy to your OC4J instance, you might experience "out of memory" errors.

Solution

Adjust the Java Virtual Machine (JVM) heap size for your OC4J processes.

See Also: "Setting the JVM Heap Size for OC4J Processes" in the chapter "Optimizing J2EE Applications In OC4J" in the Oracle Application Server Performance Guide "Administering OC4J Server Properties" in the Application Server Control Console online help

### H.3.4 "403 Forbidden - Directory browsing not allowed" Error When Testing a Web Module or Web Service

Problem

From the Application Server Control Console, you can test your Web modules to make sure they are working properly. However, in many cases, when you click the Test Module or Test Service button, the following error occurs in your Web browser:

- In Mozilla Firefox:

      403 Forbidden - Directory browsing not allowed

- In Microsoft Internet Explorer:

      You are not authorized to view this page
      You might not have permission to view this directory or page using the credentials you supplied.

Solution

Application Server Control cannot always determine the complete URL for the Web module or Web service you are testing. Instead, Application Server Control attempts to assemble the URL based on information about the root context of the Web module or Web service.

To work around this problem, use the text field on the Test Web Module or Test Web service page to enter the complete URL to your application; then, click Test Module or Test Service.

### H.3.5 Administrator Credentials Error When Attempting to Access the OC4J Home Page in a Cluster Topology

Problem

From the Cluster Topology page, you click the name of an OC4J instance and you are prompted to enter your administrator credentials. However, when you enter the proper administrator credentials, Application Server Control displays the following error:

    "Administrator credentials were saved but they cannot be used to make a
    connection.  Enter new credentials or cancel."

Solution

Check to see if the Administration OC4J instance has been configured to use the secure Remote Method Invocation (RMIS) protocol. If a remote OC4J instance you are managing is not configured for RMIS, depending upon the configuration, you may not be able to access the OC4J Home page.

For information on enabling RMIS connections for the Application Server Control Console, see Section A.3, "Configuring Security for the Application Server Control Console".

## H.4 Need More Help?

You can find more solutions on OracleMetaLink, `http://metalink.oracle.com`. If you do not find a solution for your problem, log a service request.

See Also: Oracle Application Server Release Notes, available on the Oracle Technology Network: `http://www.oracle.com/technology/documentation/index.html`