Using Caché with ODBC
Logging and Environment Variables
This chapter describes some tools you can use to perform troubleshooting. It discusses the following topics:
Enable logging only when you need to perform troubleshooting. You should not enable logging during normal operation, because it will dramatically slow down performance.
Enabling Logging for ODBC on Windows
On Windows, to enable logging for an ODBC data source, you generally use the
screen (within the Windows Control Panel). To access this screen, open the Windows Control Panel, open the Administrative Tools
subpanel, and then double-click Data Sources (ODBC)
. Or open the Windows Control Panel and then double-click
To enable logging for the client driver, find the definition of the DSN that you want to log. Different kinds of DSN are on different tabs. Click the appropriate tab. Look for a check box labeled ODBC Log
or variations) and select it.
The Log File Path
field determines the location of the trace file.
The details may vary depending on your version of Windows as well as the client driver that you use for this DSN.
The default location of the CacheODBC.log
file varies depending on the version of Windows. For Windows Vista and higher, the log will be created in the Public folder under %PUBLIC%\Logs
(default path C:\Users\Public\Logs
). This folder is accessible by all users and allows just one location for the log to be created. For earlier versions, the log is under %WINDIR%
folder, depending on your version of Windows).
Enabling Logging for ODBC on UNIX®
On UNIX®, enable logging for ODBC as follows:
If you enable logging but the log file is not updated, either you might not have privileges to write to the file or the client application may have loaded the SO before you enabled logging. In the latter case, stop and restart the client application to force it to reload the SO and get the logging flag.
InterSystems ODBC Environment Variables
This section describes the environment variables that control the InterSystems ODBC client driver. Typically you use these only for debugging or diagnostics.
This variable allows you to specify the duration of a timeout for a default login. Its value is in seconds.
This boolean variable enables the automatic appending of the process ID number to the log file name. A value of 1 enables appending and a value of 0 disables it. By default, appending is off.
CACHEODBCTRACE (UNIX® Only)
This variable specifies the location and name of the log file. This can be useful for placing the log file in a unique directory or giving it a unique name. The default location of the log file is as follows:
For UNIX®, the log is generated in the current directory by default.
For Windows platforms previous to Vista, the default location for the log file is %SYSTEMROOT%
. For Vista, the default location for the log file is %PUBLIC%\Logs\CacheODBC.log
. This directory is accessible by all users and allows just one location for the log to be created.
This variable controls whether the log also includes threading information. If the variable is 1, threading information is included; if it is 0, threading information is not included.
It can be useful to enable this additional kind of logging, if you need to debug a threaded application. However, it adds many extra lines to the log for most ODBC applications.
Trace Files on Windows 2003
There are special requirements for setting up the trace file on Windows 2003, specifically for the situation where ODBC is being run by the Web server process. In addition to ensuring that the ODBC client has permission to write to the appropriate logging directory, you need to perform the following procedure:
When specifying the log file information, you also have the option of defining the CACHEODBCPID
environment variable to include PID information. To do this, create another new variable with a name of CACHEODBCPID
and a value of 1.
Create the directory C:\ODBC_Logs
and grant universal write access to this directory.
Activate ODBC logging by selecting the ODBC Log
check box in the DSN setup screen.