Data Warehouse Center Administration Guide

Appendix A. Data Warehouse Center logging and trace data

The Data Warehouse Center provides three levels of logging capability:

To assist you in diagnosing problems, each of these logging levels contains a variety of features. This appendix describes the Data Warehouse Center logging levels and features.

The basic logging function

The basic logging function in the Data Warehouse Center captures all the events and errors that occur during run time and build time. This information is stored in the warehouse control database. The log viewer displays these run-time and build-time events and errors and any messages or return codes that pertain to them.

To view run-time (step processing) errors:

  1. Open the Data Warehouse Center desktop.
  2. Click Data Warehouse Center --> Work in Progress.

    The Operations Work in Progress window opens.

  3. Select the step for which you want to view errors.
  4. Click Log.

    The Log Viewer window opens and displays the run-time errors for the selected step.

To view build-time (table import, object creation, and step promotion) errors:

  1. Open the Work in Progress window.
  2. Click Work in Progress --> Show Log.

    The Log Viewer window opens and displays the build-time errors for the Data Warehouse Center.

For detailed explanations of return codes and error messages that the log viewer displays, see DB2 Messages and Reason Codes.

The log holds records until a designated count limit is reached. When the count limit is reached, the Data Warehouse Center automatically deletes the log.

To change the count limit for the log, see the online help for the Data Warehouse Center Properties notebook.
Note:Recommendation: Set the log record count to a size that holds 3 to 4 days worth of records.

You cannot turn off the basic logging function.

You can also view error messages with the Windows NT Application Events, which is available through the Event Viewer application.

Component trace data

Run a Data Warehouse Center trace at the direction of IBM Software Support to produce a record of a program execution. You can run an ODBC trace, a trace on the warehouse control database, and traces on the warehouse server, agent, and logger components.

When you run a trace, the Data Warehouse Center writes information to text files. Data Warehouse Center programs that are called from steps will also write any trace information to this directory. These files are located in the directory specified by the VWS_LOGGING environment variable.

The default value of VWS_LOGGING is:

The component trace data function provides information about the following components:

Windows NT and OS/2
x:\sqllib\logging

UNIX
/var/IWH

AS/400
/QIBM/UserData/IWH

The Data Warehouse Center writes these files on Windows NT:

AGNTnnnn.LOG
Contains trace information. Where nnnn is the process ID of the agent, which can be 4 or 5 characters depending on the operating system.

AGNTnnnn.SET
Contains environment settings for the agent. Where nnnn is the process ID of the agent, which can be 4 or 5 characters depending on the operating system.

IWH2LOG.LOG
Contains the results of the trace for the logger component.

IWH2SERV.LOG
Contains the results of the trace for the warehouse server.

IWH2DDD.LOG
Contains the results of the trace for the warehouse control database.

If you are running a UNIX agent, the Data Warehouse Center writes the following files on the UNIX workstation:

startup.log
Contains trace information about the startup of the warehouse agent daemon.

vwdaemon.log
Contains trace information about warehouse agent daemon processing.

To run a Data Warehouse Center component trace:

  1. Right-click the warehouse object, and click Properties.
  2. Specify the trace level for the warehouse control database, ODBC connection, server, agent, or logger as directed by IBM Software Support.
  3. Click OK.
  4. Restart the services as requested.
  5. Perform the failing operation.
  6. Repeat steps 1 through 4 to set the trace level back to 0.

Warehouse programs and transformers

The supplied warehouse programs and transformers write errors to log files.

Warehouse programs
Supplied warehouse programs write data to the directory specified in the VWS_LOGGING environment variable. Clear the directory of the log files after sending the log files to IBM Software Support.

For more information, see the online help for the specific warehouse program.

Transformers

You can log errors that are generated when you use the transformers. To enable logging, specify a log table name on the Processing Options page of the Step notebook, and add a suffix of :n to the log table name. The value of n indicates the logging level:

0
No logging

1
Log errors only

2
Log errors and warnings (this is the default logging level)

3
Log errors, warnings, and informational messages (for example, starting and stopping a transformer)

For example, to indicate a log table named MyLogTable that contains log entries at log level 3 or less, specify MyLogTable:3.

You can include a table space name after the log table name. If you want to do this, append the log level to the table space name.

For example, to indicate a log table named MyLogTable that is located in the MyTableSpace table space and contains entries at log level 3 or less, specify MyLogTable,MyTableSpace:3.

Start error trace files

The Data Warehouse Center creates three log files automatically when the logger is not running. The log file names are IWH2LOGC.LOG, IWH2LOG.LOG, and IWH2SERV.LOG. The Data Warehouse Center stores the files in the directory that is specified by the VWS_LOGGING environment variable.

The logs are:

IWH2LOGC.LOG
When the logger is not running, processes will write messages to this file. The Data Warehouse Center server and the OLE server write to this file. The file will exist only if the logger stops. The file contains the complete content of all messages that could not be sent.

IWH2LOG.LOG
The logger creates this file when it cannot start itself or when trace is activated. Key diagnostic information is written to this file when the logger cannot start itself, and cannot write to the Data Warehouse Center log. This is important in situations where DB2 is not starting or the file system is full. If you hear five beeps when the logger stops, you should look in this file. The server cannot start if the logger cannot start.

IWH2SERV.LOG
The server log contains the startup message, and will grow when the server trace is on.

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