This chapter provides a description of the tools, methods, and information sources available for troubleshooting the Sun Java System Web Server 7.0 Update 4. Guidelines for evaluating and investigating a problem are included.
As applications get deployed, un-deployed, and redeployed, and as you experiment with different server configuration settings, there may be times when your server gets into an unstable state. In such cases, it is useful to have a previously saved working configuration on which to fall back. This is not problem solving, but rather a way to avoid problems in the first place.
Refer to the Web Server Administrator's Guide for complete instructions on using the CLI and GUI options. Briefly, however, for the purposes of this Troubleshooting Guide, use the following procedure to backup the virtual servers in your configuration:
Go to Common Tasks page.
The Common Tasks page is the home page when you access the administration console. Fore information on accessing the administration console, refer to the Administrator's Guide.
Select the Configuration.
From the Configuration Tasks page, select the configuration from the drop down box.
Copy Virtual Servers.
Select the virtual server from the list and click Copy button. A window will pop up. Provide the new virtual server name and click OK. The web applications also gets copied.
Sun Java System Web Servers are typically deployed in complex and highly sophisticated operating environments. The Sun Java System Web Server covers a broad range of technologies, including Java, Java Servlets, XML, JSP, JDBC data sources, and more. Understanding and diagnosing complex issues involving so many disparate components requires thorough knowledge and a careful diagnostic process.
Gathering any or all of the following information will make it easier to classify a problem and search for solutions. Note that operating system utilities, such as pkginfo and showrev on Solaris and rpm on Linux, are helpful in gathering system information.
What are the exact version numbers of the operating system and products installed?
Have any patches been applied? If so, specify product and operating system patch numbers.
How is the system configured?
What system resources does the system have (memory, disk, swap space, and so on)?
How many web servers and directory servers are installed?
How is the Web Server connected to the directory server?
Are web servers in a cluster or not?
Was any upgrade done? If so, what were source and target versions?
Was a migration done? If so, what were source and target versions?
Have any new web applications been deployed?
Is SSL enabled or not?
What database is being used?
What JDBC driver is being used to access the database?
What JDK version is being used?
What are the JVM heap, stack, and garbage collection-related parameters set to?
What are the JVM options?
What third-party technologies are being used in the installation?
Are the interoperating component versions in compliance with the compatibility matrix specified in the release notes?
After gathering this information:
Collect web server error and access log data (web server instance-specific).
Collect any Web Server stack traces. Note that a fresh set of logs associated with the specific problem should be run. This avoids scanning gigabytes of irrelevant log information.
Determine the sequence of events that occurred when the problem first appeared, including any steps that may already have been taken to resolve the problem.
When you encounter a problem, do not panic. It is better to approach the problem more systematically by collecting the necessary system specific details.
The following topics are addressed in this section:
Sometimes the most obvious solutions are overlooked, and so the first step is to verify the system configuration. Refer to the Sun Java System Web Server 7.0 Update 4 Release Notes for the most up-to-date system requirements and dependencies.
Messages generally include information about the attempted action, the outcome of the action, and, if applicable, the cause of jeopardy or failure.
The log files contain the following general types of message entries:
Error – These messages mark critical failures that cause status to be reported as Failed. Error messages generally provide detailed information about the nature and the cause of the problem that occurred.
Warning – These messages mark non-critical failures. Warning messages generally contain information about the cause and the nature of the failure, and also provide possible remedies.
Information – These messages mark normal completion of particular tasks.
In some cases, the message is very clear about what is wrong and what needs to be done, if anything, to fix it. For example the 'Deployment Pending' link that appears on the administration console whenever an instance configuration is modified.
In this case, the message gives clear guidance and the problem can be disregarded.
Sometimes an error message gives only general information about the problem or solution, or suggests multiple possibilities.
In this case, the problem is not obvious, or there might be multiple things wrong. You might have to consider various possibilities and perhaps a number of solutions. If the proposed fix is time consuming or costly, take steps to ensure that the fix is likely to be correct before actually doing anything.
Some error messages are either not helpful or provide little guidance.
In this case, there is very little information to go on. It is especially important to identify the exact situation that caused the error, and what the symptoms are before proceeding.
For descriptions of all the Web Server error messages, refer to the later sections in this guide.
Web Server Error Logs are the first place you should look for information, when you need to troubleshoot a runtime issue. For issues related to installation, see the installation log files.
In addition to the message text, a logged message provides the following information:
Date and time of the event
Log level for the event — Web Server-specified log level ID or name
Process identifier (PID) — PID of the Web Server process
(optional) Virtual server identifier (VSID) — VSID that generated the message
Message identifier (MID) — subsystem and a four digit integer
The specific logs associated with each Web Server problem area are discussed in the associated chapters of this manual.
The Web Server has many log levels that can be set in the Administration GUI (FINEST, FINER, FINE, CONFIG, INFO, WARNING, SEVERE, ALERT, and FATAL). All messages are logged when the log level is set to FINEST and only serious error messages appear if the log level is set to FATAL.
Note that the more detailed log levels (FINEST, FINER, FINE) can generate high volumes of log information for certain events, which may make it appear at first glance that there is an error condition when in fact there is not.
All messages with a log level less than the default level of INFO (FINEST, FINER, FINE, and CONFIG) provide information related to debugging and must be specifically enabled. Instructions for doing this are contained in the Sun Java System Web Server Administrator's Guide.
In addition to the standard JDK log levels, the Web Server has added log levels designed to map more intuitively to the Web Server log file (server.log) and to tightly integrate with Solaris. The log levels ALERT and FATAL are specific to the Web Server and are not implemented in the JDK1.4 logging API.
For information on the event log mechanism used in the Microsoft Windows operating environment, refer to the Windows help system index using the keywords Event Logging. If you choose to send logs to the Windows server.log file, only messages with a log level of INFO, WARNING, SEVERE, ALERT, or FATAL are logged to the Windows Event Log.
The Administration GUI provides the following two logging options:
Option 1 — Log stdout (System.out.print) content to the event log
Option 2 — Log stderr (System.err.print) content to the event log
If the above options are not set:
Anything written to stdout or stderr (that is, using System.out or System.err) will not appear in the logs.
Messages logged with the JDK logger will appear in the logs.
Messages written to stdout or stderr appear with the INFO level, but do not have a message ID.
A good initial step is to scan this Troubleshooting Guide to see if the problem is addressed here. If so, select the appropriate solution. Many of the solutions contain references to other documents in the Web Server document collection for additional details, explanations, or examples.
Start by reading the Release Notes for the version of the product you are troubleshooting.
The documentation for this Web Server product release is available at Sun Java System Web Server 7.0 Update 4 Documentation Center.
Go to SunSolve.
Under SunSolve Collections, click the Search Collections link.
Select the checkbox for the collection(s) to search.
Enter the search criteria.
Browse directly in any of the online forums, or log in and register to start posting messages. The Web Server online forum is available at: http://swforum.sun.com/jive/index.jsp?cat=7
When necessary, gather together the information you have acquired and contact technical support at http://www.sun.com/service/contacting.