DB2 Server for VSE & VM: Operation

Isolating Problems

You can use either the ISQLMAP or the ISQLTRACE commands to isolate problems within the ISQL facility.

ISQLMAP

The ISQL facility contains its own load module map, which is invoked by the command:

 ISQLMAP

ISQL Dumps in DB2 Server for VSE

Use of CICS dumps in problem diagnosis is presented in the CICS Problem Determination Guide

ISQL In-Core Trace

The ISQL facility lets you trace activity within ISQL. Items that are traced include:

• Calls to and returns from ISQL modules
• SQL return codes
• ISQL messages.

The trace is always active. It stores a limited amount of information internally in a trace table.

The initial trace table holds 50 entries. After 50 entries are made, the table wraps and only the last 50 entries to the table are kept. To change the size of the internal table and select how trace information is to be displayed, issue the ISQLTRACE command.

>>-ISQLTrace----+-DUMP----+------------------------------------>< +-DISPLAY-+ '-n-------'

DUMP

creates an unformatted storage dump hardcopy of the trace table.

In a VSE system, the ISQL facility issues a CICS dump to the CICS dump data set. You should use your installation's usual job for printing the dump data set.

In a VM system, the ISQL facility issues a CP DUMP command. The dump uses the printer with the lowest virtual address. The application server issues a CP CLOSE PRINT to close the print file. This also closes any other open print files.

DISPLAY

displays the formatted trace table on the display. If more than 50 (or n) entries have been made into the trace table, the entries wrap. Only the last 50 (or n) entries in the table are displayed. The entries are displayed last in, first out, in the reverse of the order they were put in the table. Figure 89 shows the internal storage layout of these entries in DB2 Server for VM.

n

to change the size of the trace table. Replace n with the number of trace entries that are to be contained in the trace table. n must be a number from 50 to 1000.

Figure 89. Internal Storage of the ISQL Trace Table on VM

TRMOD   CHAR(8)	TRCMOD   CHAR(8)	TRR15   FIXED(31)	TRLBL   FIXED(15)	TRCODE   CHAR(1)	TRCHAR   CHAR(5)
calling- returning module	called module	address or return code	2-byte label number	C-calls or R-return	5-bytes char mod dep info
For Example:
ARIISTR ARIISQL1	ARIISQL1 (hex 0)	0048A808   00000004	0002   0001	C   R	SEL   EXITS

TRMOD

is the module issuing the call or return.

TRCMOD

is the module being called.

TRR15

holds the value of register 15 at the time of the entry, which is the address of the called module or the return code.

TRLBL

is the number associated with the label of the CALL or RETURN:

A label of TRLC7 would have a TRLBL number = 7, and would be the 7th CALL issued from the module.

A label of TRLR3 would be the third RETURN issued from the module, and would have a TRLBL number = 3.

TRCODE

C indicates a CALL label, R indicates a RETURN label.

TRCHAR

contains module-dependent information. The information saved here varies for each module. It is a maximum of 5 bytes.

The following is an example output of the ISQLTRACE DISPLAY command. The addresses, label numbers, and character information are not shown in the example.

Figure 90. A Typical Example ISQLTRACE DISPLAY Output

ARI7181I ISQL trace table display. First entry: 2B36F0 Current entry: 2B3C50 Last entry: 2B3D10 ARIIPSQ CALLED ARIITKN,R15= 443E60,TRLBL= 0001,TRCHAR= TKN1 RETURN FROM ARIITKN,R15= 000000,TRLBL= 0003,TRCHAR= ARIIPSQ CALLED ARIITKN,R15= 443E60,TRLBL= 0015,TRCHAR= TKN2 RETURN FROM ARIITKN,R15= 000000,TRLBL= 0003,TRCHAR= ARIIPSQ CALLED ARIIPQY,R15= 44C8B0,TRLBL= 0018,TRCHAR= SEL ARIIPQY CALLED ARIICNV,R15= 458860,TRLBL= 0001,TRCHAR= CONS RETURN FROM ARIICNV,R15= 000010,TRLBL= 0001,TRCHAR= DECC ARIIPQY CALLED ARIIGM ,R15= 44220E,TRLBL= 0031,TRCHAR= SQLDA · · ·