Tracing

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 the MAS JDBC Driver. The sections below cover the following topics:

An overview of 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.

Example of trace output data

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

Planning considerations

Before using the MAS Trace Facility, there are some important factors to consider. These include:

Configuring data sources

Make sure you have configured a dynamic data source. (See Configuring the JDBC driver).

Performance issues

The MAS Trace Facility is a debugging tool that can slow the execution of your JDBC 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.

Controlling trace logfiles

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.

Copyright IBM Corp. 1997, 2004