The MAS Trace Facility can be very useful in solving problems
that can occur during installation and use. You can enable the
client side trace for both the MAS ODBC Driver and the MAS JDBC
Driver. The sections below cover the following topics:
- An overview
- Planning considerations
- Configuring a data source
- Performance issues
- Controlling trace log files
- Enabling the MAS Trace Facility
- Controlling the MAS Trace Facility
The MAS Trace Facility traces selected events. It creates a file
named NEONLOG.TXT in a selected directory and records the traced
events in that file. If a file by that name is already present, the
trace facility adds any newly recorded events to it.
The format of the trace output data always includes a date,
time, and pertinent information about each event.
Fri Oct 01 22:19:30 1993 pcbColName = 0x0a5f:759a
Fri Oct 01 22:19:30 1993 pfSqlType = 0x0a5f:759e
Fri Oct 01 22:19:30 1993 pcbColDef = 0x0a5f:75a0
Fri Oct 01 22:19:30 1993 pibScale = 0x0a5f:7594
Fri Oct 01 22:19:30 1993 pfNullable = 0x0a5f:759c
Fri Oct 01 22:19:30 1993 SQLDescribeCol exiting - return = SQL_SUCCESS(0)
Fri Oct 01 22:19:30 1993 szColName = 'REMARKS'
Fri Oct 01 22:19:30 1993 *pcbColName = 7
Fri Oct 01 22:19:30 1993 *pfSqlType = SQL_CHAR(1)
Fri Oct 01 22:19:30 1993 *pcbColDef = 64
Fri Oct 01 22:19:30 1993 *pibScale = 9999
Fri Oct 01 22:19:30 1993 *pfNullable = SQL_NULLABLE_UNKNOWN(2)
Fri Oct 01 22:19:30 1993 SQLFetch entered
Fri Oct 01 22:19:30 1993 lpstmt = 0x095f:0000
Fri Oct 01 22:19:30 1993 internal error detected: file scodbcre.c line 1228 rc =
0 from scclxlat
Fri Oct 01 22:19:30 1993 SQLFetch exiting - return = SQL_SUCCESS(0)
Fri Oct 01 22:19:30 1993 SQLGetData entered
Fri Oct 01 22:19:30 1993 lpstmt = 0x095f:0000
Before using the MAS Trace Facility, there are some important
factors to consider. These include:
- Configuring a data source
- Performance issues
- Controlling trace log files
Make sure you have configured a dynamic data source. (See
"Configuring the ODBC
driver").
The MAS Trace Facility is a debugging tool that can slow the
execution of your ODBC application. Because of this, you may want
to turn it off once you have the driver and your applications
operating perfectly. This can be done by setting up the DOS
environment variable SET NEONTRACE=NONE.
If a fully qualified pathname (including a directory) for the
NEONLOG.TXT file has not been specified, the MAS Mainframe
Agent creates the NEONLOG.TXT file in the current
directory. Over time, this could result in several
NEONLOG.TXT files in several different directories. These
files can become very large, especially if you are using a low
severity level trigger to trace events. These files should be
deleted as necessary.
- Open the ODBC Data Source Administrator.
- Select the Tracing Tab.
- Click Start Tracing Now.
- Click OK.
- Follow steps 1 through 3 for "Enabling
the MAS ODBC driver trace for Windows".
- Add the following item to the NEONTRACE environment variable in
DOS:
JDBCLOG=xyz
where xyz is the full pathname of a log file. For
example, on Windows NT, you may have:
THREADID INFO BUFFER JDBCLOG=C:\temp\neonjdbc.txt LOG=C:\temp\neonlog.txt
- Note:
- The JDBCLOG keyword must precede the LOG keyword.
Two separate files will be generated: one for the ODBC driver
and one for the JDBC driver.
- Click OK.
To perform the trace in the Windows NT environment if you are
running in TYPE1 mode (default), ensure that the trace file
specified in the data source has the same file name as the one
specified in the LOG keyword. If you omit the LOG keyword from the
NEONTRACE parameter, the trace will be written to the
trace file specified in the data source.
The MAS Trace Facility's default values provide adequate tracing
in most cases. However, you might need to change the MAS Trace
Facility's severity level trigger or tracing options. You can do
this in one of the following ways:
- Selecting the options using the Debug Information dialog
box.
- Setting the appropriate NEONTRACE environment variable
in DOS.
The most commonly used method for controlling the MAS Trace
Facility is to use the Debug Information dialog box. This
lists all of the options available to you and ensures that the
correct keyword is changed in the ODBC.INI file.
- Open the Start menu and select
Settings/Control Panel (if you are using Windows 95
or higher) or Settings/Control Panel/Administrative Tools
(if you are using Windows NT 3.0 or higher).
- Double-click the ODBC Data Sources icon (or item, if
viewing by List or Details).
The system displays the ODBC Data Source
Administrator dialog box.
- From the User Data Sources list, select the appropriate
data source.
- Click Configure. The system displays a configuration
dialog box, as shown in Figure 13.
Figure 13. Debug configuration

- Click Advanced. The system displays the Advanced
Information dialog box (Figure 14).
Figure 14. Advanced information

- Click Debug. The system displays the Debug
Information dialog box (Figure 15).
Figure 15. Client debug information

- Note:
- If you had selected IMS as your client type from the
configuration dialog box shown in Figure
13, the Debug button would have appeared on the Advanced
Information dialog box, shown in Figure
14
- Select the appropriate severity level trigger of the events to
be traced. When a severity level is selected, all events at and
above that severity level will be traced and recorded. The severity
options are listed below from the highest to the lowest level:
- NONE: With this option, no messages are traced or
recorded. No trace file is created or opened. This option
effectively turns off the MAS Trace Facility.
- FATAL: This option, the highest severity level, causes
only program termination messages to be traced and recorded.
- SEVERE: (Default selection) This option causes only
events of a severe or higher level to be traced and recorded.
- ERROR: This option causes all error messages to be
traced and recorded. These messages usually include a description
of what went wrong, a record of where the error was detected, any
relevant return code, and a detailed error text message.
- WARNING: This option allows any warning messages issued
by the MAS ODBC Driver to be traced and recorded.
- INFO: This option allows all informational events to be
traced. Note that values passed to and returned from the MAS ODBC
Driver are included here. This option will cause a large quantity
of information to be traced and recorded and is not recommended for
general use. However, this option can be useful for application
debugging.
- DETAIL: This option, the lowest severity level, causes
all events, including function call events, to be traced. This
value will cause huge amounts of information to be traced and
recorded, and it is not recommended for general use.
- Select additional options by clicking the appropriate boxes.
The additional options include the following:
- STAY: This option keeps the trace file open. This can
improve performance if you are using a disk file to store trace
messages.
- FLUSH: Use this option with STAY. It helps to ensure
that messages are not lost if your machine fails.
- STORAGE: This option causes all storage GET and FREE
operations to be traced. The trace record shows the name of the
file requesting or freeing the storage area and the line number
within the file. The record also indicates the size of the data
area being obtained or freed, the address of the data area, and
other important information. The final storage report is generated
in the Windows environment when the DLL containing the storage
manager functions is unloaded.
- DATA: This option causes all conversion operations to
and from DB2, ODBC C, and ODBC SQL data types to be traced. In each
case, the input and output data is displayed in hexadecimal and
character format. In addition, information is provided that
designates which row and column of the table is currently being
processed.
- SQL: This option causes all SQL statements passed to the
host to be traced, even if the trace severity level is higher than
INFO. It also causes the column information for SELECT statements
to be displayed, including the column number, name, and data type.
For SQL_NUMERIC and SQL_DECIMAL data types, the precision and scale
values are also displayed.
- Click Select. The system displays the Select Trace
File dialog box (Figure 16).
Figure 16. Select Trace File

- Select a name and directory for the trace file.
- Click OK to return to the Debug Information
dialog box (shown in Figure 15).
- Click OK.
This writes a NEONTRACE keyword in the appropriate
section of the ODBC.INI file. The NEONTRACE
keyword will reflect the options you selected with the data source
that you selected from the ODBC Data Source Administrator.
The contents of the ODBC.INI file augment and override any
DOS environment variable values set earlier using the SET
NEONTRACE=[string] command.
The other approach for controlling the MAS Trace Facility is to
set a trace environment variable in DOS. To set this variable, use
the following form:
SET NEONTRACE=[string]
where [string] consists of the options you select,
delimited with spaces.
Set this variable in one of the following ways:
- Manually enter the SET NEONTRACE=[string] command from
the DOS command line.
- Add the SET NEONTRACE=[string] command to the
AUTOEXEC.BAT and CONFIG.SYS files. Reboot your
computer for the command to take effect.
- Note:
- If you prefer to enter the command manually, be sure to do so
within DOS itself and not through a DOS window while Windows is
still running. Setting the trace environment variable from a DOS
window (which uses a second-level command processor) will have no
effect at all on the MAS Trace Facility.
