A fix is available
APAR status
Closed as program error.
Error description
5655M1500 Several of the CICS DB2 Global Statistics, headings and descriptions, are confusing. Headings meaning column headings within the DFHSTUP utility output. Descriptions meaning the field descriptions, for the associated heading, as shown in the Performance Guide. The specific fields in question are: D2G_TCB_FREE, D2G_TCB_HWM and D2G_TCB_CURRENT. These fields and associated headings of DFHSTUP utility output are confusing due to their reference of TCB usage. D2G_TCB_FREE relates to heading 'Current number of Free TCBs' within DFHSTUP utility output. This value is taken from field glb_free_conn_count (free connections (CSUBs) not TCBs) when the TCB pool being checked is openapi. The description of D2G_TCB_FREE, in the Performance Guide, points out the meaning of the heading/field in regard to DB2 version 6 and higher versus DB2 version 5. Since DB2 version 5 is now prehistoric, it makes sense to update the heading to 'Current number of Free Connections' or 'Current number of Free CSUBs'. D2G_TCB_HWM is much the same way when open api is relevent. D2G_TCB_HWM is taken from glb_current_associated_csubs_hwm. This is the HWM for ASSOCIATED CSUBS (meaning the connection was associated with a TCB at one time). It is not a HWM of TCBs, thus additional thought should be taken to possibly change the heading of 'Peak number of TCBs' to something more meaningful like 'Peak number of Associated Connections' or 'Peak number of Associated CSUBS'. Additional thought of updating the description for this field within the Performance Guide should also be taken into consideration as it explains the meaing as Peak number of TCBs as well. If the descriptions is also different with regard to pre DB2 version 6, additional information should also be added as was done for the D2G_TCB_FREE field. D2G_TCB_CURRENT = glb_current_associated_csubs in regard to openapi. This relates to the current number of ASSOCIATED CSUBs and not the Current number of TCBs. Thus, the heading of 'Current number of TCBs' should also change to something like 'Current number of Associated CSUBs'. The description within the Performance Guide should also change to reflect this and, if meaning is different pre DB2 version 6, should have that information added.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All. * **************************************************************** * PROBLEM DESCRIPTION: Some of the headings in the DB2 * * part of the Statistics Utility * * program are misleading. The term * * 'TCB' is used, but 'Connection' is a * * more meaningful description. * **************************************************************** * RECOMMENDATION: * **************************************************************** When CICS is connected to DB2 Version 6 or later, the TCBs used for DB2 threads are no longer dedicated to the DB2 interface as they were with DB2 Version 5 and earlier. Instead, there is a pool of L8 TCBs that can be used for DB2 threads and other purposes, such as threadsafe application programs. DB2 connections (or CSUBs) become associated with, and freed from, these pooled TCBs as needed. However, the statistics report from the DFHSTUP utility program does not reflect this correctly. It still refers to TCBs, giving a misleading view of the usage of the DB2 connections. As the CICS Transaction Server for z/OS Version 3 Release 1 Release Guide (GC34-6421-04) states that DB2 is only supported at Version 6 and above, it is no longer appropriate for the DFHSTUP statistics report to refer to TCBs as with earlier versions of DB2. Similar updates need to be done to the reports by DFH0STAT and DFH0STXR. Additional keywords: openapi DFH0STAT 0STAT STAT DFHSTUP STUP
Problem conclusion
DFHSTUD2 has been modified to use the term 'Connections' instead of 'TCBs' where appropriate, in the 'DB2 CONNECTION STATISTICS' part of the report. Also the IBM-supplied COBOL sample programs DFH0STDB and DFH0STXR have been modified to use 'Connections' and 'TCBs Connected' where appropriate, instead of 'TCBs'. The CICS Transaction Server for z/OS Version 3 Release 1 CICS Performance Guide, SC34-6452-03, will be changed in the following places: 1. Appendix A "CICS Statistics Tables", Section 2.1 "CICS DB2: Global Statistics", Table 21. In the 9th row of the table: - in the 'DFHSTUP name' column, change 'Current number of TCBs' to 'Current number of Connections' - in the 'Description' column, change the text to 'is the current number of connections used by the CICS-DB2 attachment facility'. Leave the Reset characteristic unchanged In the 10th row of the table: - in the 'DFHSTUP name' column, change 'Peak number of TCBs' to 'Peak number of Connections' - in the 'Description' column, change the text to 'is the peak number of connections used by the CICS-DB2 attachment facility'. Leave the Reset characteristic unchanged In the 11th row of the table: - in the 'DFHSTUP name' column, change 'Current number of free TCBs' to 'Current number of free Connections' - in the 'Description' column, change the text to 'is the number of free connections available for use with CICS open TCBs'. Leave the Reset characteristic unchanged 2. Appendix E "The sample statistics program, DFH0STAT", Section 58 "DB2 Connection Report". In Figure 123 (the sample report), change 'TCBs' to 'Connections' in the following 3 fields: - Current number of TCBs - Current number of free TCBs - Peak number of TCBs In Table 247: In the 29th row of the table: - in the 'Field Heading' column, change 'Current number of TCBs' to 'Current number of Connections' - in the 'Description' column, change the text to 'The current number of connections in use by the CICS DB2 attachment facility'. Leave the Source field unchanged In the 30th row of the table: - in the 'Field Heading' column, change 'Peak number of TCBs' to 'Peak number of Connections' - in the Description column, change the text to 'The peak number of connections used by the CICS DB2 attachment facility'. Leave the Source field unchanged In the 31st row of the table: - in the 'Field Heading' column, change 'Current number of free TCBs' to 'Current number of free Connections' - in the 'Description' column, change the text to 'The number of free connections available for use with CICS open TCBs'. Leave the Source field unchanged
Temporary fix
CICS AR400 AR401 AR400 FIX AVAILABLE BY PTF ONLY ++ APAR (AK25021). ++ VER (C150) FMID(JCI6401). ++ MACUPD (DFH0STDB) DISTLIB(ADFHSAMP) SYSLIB(SDFHSAMP) /* MODULE: DFH0STDB --- TYPE: COBOL */. ./ CHANGE NAME=DFH0STDB,SEQFLD=738 MOVE 'Current number of Connections. . . . . . :' TO PP3-44. 88016000 MOVE 'Current number of free Connections. . . . . :' 88032000 MOVE 'Peak number of Connections . . . . . . . :' TO PP3-44. 88066000 ./ ENDUP ++ MACUPD (DFH0STXR) DISTLIB(ADFHSAMP) SYSLIB(SDFHSAMP) /* MODULE: DFH0STXR --- TYPE: COBOL */. ./ CHANGE NAME=DFH0STXR,SEQFLD=738 03 FILLER PIC X(26) 08260000 VALUE 'Peak DB2 TCBs connected = '. 08280000 03 D2-W-001-DB2-TCBS PIC ZZ9. 08300000 03 FILLER PIC X(23) 08320000 ./ ENDUP
Comments
APAR Information
APAR number
PK25021
Reported component name
CICSTS 3.1 Z/OS
Reported component ID
5655M1500
Reported release
400
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2006-05-16
Closed date
2006-06-23
Last modified date
2006-07-05
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK15683 UK15684
Modules/Macros
DESSTD2X DESSTUD2 DFHD2DUF DFHSTD2H DFHSTD2X DFHSTUD2 DFH0STDB DFH0STXR
| SC34645203 |
Fix information
Fixed component name
CICSTS 3.1 Z/OS
Fixed component ID
5655M1500
Applicable component levels
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
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Document Information
Modified date:
05 July 2006