LSRpool statistics

CICS® supports the use of up to eight LSRpools, and produces two sets of statistics for LSRpool activity.

This section contains the following statistics:

LSRpool: Resource statistics for each LSRpool

The following information describes the size and characteristics of the pool, and shows the data collected for the use of strings and buffers.

These statistics can be accessed online using the EXEC CICS COLLECT STATISTICS LSRPOOL command, and are mapped by the DFHA08DS DSECT. For programming information about the EXEC CICS COLLECT STATISTICS command, see the CICS System Programming Reference manual.

Table 90. LSRpool: Resource statistics for each LSRpool
DFHSTUP name Field name Description
Pool Number A08SRPID is the identifying number of the pool. This value may be in the range 1 through 8.

Reset characteristic: not reset

 

NOT IN THE DFHSTUP REPORT A08FLAGS is a flag set to value X'80' if separate data and index pools are used, or set to value X'00' if data and index buffers share the same pool.

Reset characteristic: not reset

 

Time Created A08LKCTD is the time when this LSRpool was created. The DFHSTUP report expresses this time as hours:minutes:seconds.decimals in local time.

Reset characteristic: not reset

 

Time Deleted A08LKDTD is the local time (STCK) when this LSRpool was deleted. This field is printed only if the pool has been deleted (that is, if all the files using the pool have been closed). If no value is set, the DSECT field contains the packed hexadecimal value X'00000000 00000000'.

This field is only printed for unsolicited statistics when the pool is deleted.

The process of deleting an LSRpool results in the output of unsolicited statistics for the pool. Information for the deleted pool is not printed in subsequent statistics output. For this reason, the "time pool deleted" field is normally printed only in this unsolicited statistics output.

Reset characteristic: not reset

 

NOT IN DFHSTUP REPORT A08GBKCD is the time when this LSRpool was created. The DFHSTUP report expresses this time as hours:minutes:seconds.decimals in GMT.

Reset characteristic: not reset

 

NOT IN DFHSTUP REPORT A08GBKDD is the time when this LSRpool was deleted expressed in GMT. This field is printed only if the pool has been deleted (that is, if all the files using the pool have been closed). If no value is set, the DSECT field contains the packed hexadecimal value X'00000000 00000000'

This field is only printed for unsolicited statistics when the pool is deleted.

The process of deleting an LSRpool results in the output of unsolicited statistics for the pool. Information for the deleted pool is not printed in subsequent statistics output. For this reason, the "time pool deleted" field is normally printed only in this unsolicited statistics output.

Reset characteristic: not reset

 

Maximum key length A08BKKYL is the length of the largest key of a VSAM data set which may use the LSRpool. The value is obtained from one of:
  • The MAXKEYLENGTH option of the DEFINE LSRPOOL command in resource definition online, if it has been coded
  • A CICS calculation at the time the LSRpool is built.

Reset characteristic: not reset

 

Total number of strings A08BKSTN is the value obtained from one of:
  • The STRINGS option of the DEFINE LSR command in resource definition online, if it has been coded
  • A CICS calculation at the time the LSRpool is built.

Reset characteristic: not reset

 

Peak requests that waited for string A08BKHSW is the highest number of requests that were queued at one time because all the strings in the pool were in use.

Reset characteristic: reset to current value

 

Total requests that waited for string A08BKTSW is the number of requests that were queued because all the strings in the pool were in use. This number reflects the number of requests that were delayed during CICS execution due to a restriction in LSRpool string resources.

Reset characteristic: reset to zero

 

Peak concurrently active strings A08BKHAS is the maximum number of strings that were active during CICS execution. If you have coded a value for the number of strings the pool is to use, this statistic is always less than or equal to the value you have coded. If your coded value for string numbers is consistently higher than this value in the statistics, you could consider reducing it so that your pool of VSAM strings is not bigger than you need.

Reset characteristic: reset to current value

 

Note that if separate data and index pools are not being used, all the statistics for the totals are obtained from the A08TOxxx_DATA variables, the index totals being unused.

LSRpool: Data buffer statistics

Table 91. LSRpool: Data buffer statistics
DFHSTUP name Field name Description
Size A08BKBSZ is the size of the buffers that are available to CICS. Buffers may be specified through:
  • The DEFINE LSRPOOL command of resource definition online
  • A CICS calculation at the time the LSRPOOL is built, of the buffers to use.

Reset characteristic: not reset

 

Number A08TOBFN_DATA is the number of data buffers used by the pool.

Reset characteristic: not reset

 

Lookasides A08TOBFF_DATA is the number of successful lookasides to data buffers for the pool.

Reset characteristic: not reset

 

Reads A08TOFRD_DATA is the number of read I/Os to the data buffers for the pool.

Reset characteristic: not reset

 

User writes A08TOUIW_DATA is the number of user-initiated buffer WRITEs from data buffers for the pool.

Reset characteristic: not reset

 

Non-user writes A08TONUW_DATA is the number of non-user-initiated buffer WRITEs from data buffers for the pool.

Reset characteristic: not reset

 

LSRpool: Hiperspace data buffer statistics

Table 92. LSRpool: Hiperspace data buffer statistics
DFHSTUP name Field name Description
Size A08BKBSZ is the size of the buffers that are available to CICS. Buffers may be specified through:
  • The DEFINE LSRPOOL command of resource definition online
  • A CICS calculation at the time the LSRPOOL is built, of the buffers to use.

Reset characteristic: not reset

 

Number A08TOHBN_DATA is the number of Hiperspace™ data buffers specified for the pool

Reset characteristic: not reset

 

Hiperspace reads A08TOCRS_DATA is the number of successful CREAD requests issued to transfer data from Hiperspace data buffers to virtual data buffers.

Reset characteristic: not reset

 

Hiperspace writes A08TOWRS_DATA is the number of successful CWRITE requests issued to transfer data from virtual data buffers to Hiperspace data buffers.

Reset characteristic: not reset

 

Hiperspace failed reads A08TOCRF_DATA is the number of CREAD requests that failed. MVS™ had withdrawn the space and VSAM had to read data from DASD.

Reset characteristic: not reset

 

Hiperspace failed writes A08TOCWF_DATA is the number of CWRITE requests that failed. There was insufficient Hiperspace and VSAM had to write data to DASD.

Reset characteristic: not reset

 

LSRpool: Index buffer statistics

Table 93. LSRpool: Index buffer statistics
DFHSTUP name Field name Description
Size A08BKBSZ is the size of the buffers that are available to CICS. Buffers may be specified through:
  • The DEFINE LSRPOOL command of resource definition online
  • A CICS calculation at the time the LSRPOOL is built, of the buffers to use.

Reset characteristic: not reset

 

Number A08TOBFN_INDX is the number of index buffers used by the pool.

Reset characteristic: not reset

 

Lookasides A08TOBFF_INDX is the number of successful lookasides to index buffers for the pool.

Reset characteristic: not reset

 

Reads A08TOFRD_INDX is the number of read I/Os to the index buffers for the pool.

Reset characteristic: not reset

 

User writes A08TOUIW_INDX is the number of user-initiated buffer WRITEs from index buffers for the pool.

Reset characteristic: not reset

 

Non-user writes A08TONUW_INDX is the number of non-user-initiated buffer WRITEs from index buffers for the pool.

Reset characteristic: not reset

 

LSRpool: Hiperspace index buffer statistics

Table 94. LSRpool: Hiperspace index buffer statistics
DFHSTUP name Field name Description
Size A08BKBSZ is the size of the buffers that are available to CICS. Buffers may be specified through:
  • The DEFINE LSRPOOL command of resource definition online
  • A CICS calculation at the time the LSRPOOL is built, of the buffers to use.

Reset characteristic: not reset

 

Number A08TOHBN_INDX is the number of Hiperspace index buffers specified for the pool

Reset characteristic: not reset

 

Hiperspace reads A08TOCRS_INDX is the number of successful CREAD requests issued to transfer data from Hiperspace index buffers to virtual index buffers.

Reset characteristic: not reset

 

Hiperspace writes A08TOWRS_INDX is the number of successful CWRITE requests issued to transfer data from virtual index buffers to Hiperspace index buffers.

Reset characteristic: not reset

 

Hiperspace failed reads A08TOCRF_INDX is the number of CREAD requests that failed. MVS had withdrawn the space and VSAM had to read data from DASD.

Reset characteristic: not reset

 

Hiperspace failed writes A08TOCWF_INDX is the number of CWRITE requests that failed. There was insufficient Hiperspace and VSAM had to write data to DASD.

Reset characteristic: not reset

 

The following group of statistics fields describes the characteristics and usage of the different buffer sizes available for use by the pool. These statistics are available online, and are mapped by the A08BSSDS DSECT defined in the DFHA08DS DSECT. This DSECT is repeated for each of the 11 CISIZEs available.

LSRpool: Buffer statistics

Table 95. LSRpool: Buffer statistics
DFHSTUP name Field name Description
Buffer Size A08BKBSZ is the size of the buffers that are available to CICS. Buffers may be specified through:
  • The DEFINE LSRPOOL command of resource definition online
  • A CICS calculation at the time the LSRPOOL is built buffers to use.

Reset characteristic: not reset

 

Number A08BKBFN lists the number of buffers of each size available to CICS:

Reset characteristic: not reset

 

Lookasides A08BKBFF is the number of read requests that VSAM was able to satisfy without initiating an I/O operation; that is, the requested record, whether index or data, was already present in one of the buffer resident CIs. This means that no physical I/O had to be done to put the control interval in the buffer.

The tuning methodology usually employed involves either increasing the number of buffers of a particular CI size until the ratio of lookasides to READs stops increasing significantly or, conversely, reducing the number of buffers until the ratio of lookasides to READs begins to drop significantly. For most data sets, successful lookaside hits on indexes are more likely.

These statistics are obtained from VSAM and represent the activity after the pool was created. Note that these statistics are not reset by CICS under any circumstances.

Reset characteristic: not reset

 

Reads A08BKFRD is the number of I/O operations to the buffers that VSAM was required to initiate to satisfy the CICS application’s activity. This figure represents failures to find the control interval in the buffers.

These statistics are obtained from VSAM and represent the activity after the pool was created. Note that these statistics are not reset by CICS under any circumstances.

Reset characteristic: not reset

 

User writes A08BKUIW is the number of user-initiated I/O WRITE operations from the buffers that VSAM was required to initiate to satisfy the CICS application’s activity.

These statistics are obtained from VSAM and represent the activity after the pool was created. Note that these statistics are not reset by CICS under any circumstances.

Reset characteristic: not reset

 

Non-user writes A08BKNUW is the number of non-user initiated I/O WRITE operations from the buffers that VSAM was forced to initiate due to no buffers being available for reading the contents of a CI.

These statistics are obtained from VSAM and represent the activity after the pool was created. Note that these statistics are not reset by CICS under any circumstances.

Reset characteristic: not reset

 

LSRpool: Hiperspace buffer statistics

Table 96. LSRpool: Hiperspace buffer statistics
DFHSTUP name Field name Description
Size A08BKBSZ is the size of the buffers that are available to CICS. Buffers may be specified through:
  • The DEFINE LSRPOOL command of resource definition online
  • A CICS calculation at the time the LSRPOOL is built, of the buffers to use.

Reset characteristic: not reset

 

Number A08BKHBN is the number of Hiperspace buffers specified for the pool.

Reset characteristic: not reset

 

Hiperspace reads A08BKCRS is the number of successful CREAD requests issued to transfer data from Hiperspace buffers to virtual buffers.

Reset characteristic: not reset

 

Hiperspace writes A08BKCWS is the number of successful CWRITE requests issued to transfer data from virtual buffers to Hiperspace buffers.

Reset characteristic: not reset

 

Hiperspace failed reads A08BKCRF is the number of CREAD requests that failed. MVS had withdrawn the space and VSAM had to read data from DASD.

Reset characteristic: not reset

 

Hiperspace failed writes A08BKCWF is the number of CWRITE requests that failed. There was insufficient Hiperspace and VSAM had to write data to DASD.

Reset characteristic: not reset

 

These Hiperspace statistics are obtained from VSAM and represent the activity after the pool was created. Note that these statistics are not reset by CICS under any circumstances.

 

LSRpool: Summary resource statistics for each LSRpool

Summary statistics are not available online.

Table 97. LSRpool: Summary resource statistics for each LSRpool
DFHSTUP name Description
Total number of pools built is the total number of LSRPOOLS that were built during the entire CICS run.

 

Peak requests that waited for string is the highest number of requests that were queued at one time because all the strings in the pool were in use.

 

Total requests that waited for string is the total number of requests that were queued because all the strings in the pool were in use. This number reflects the number of requests that were delayed during CICS execution due to a restriction in LSRpool string resources.

 

Peak concurrently active strings is the peak number of strings that were active during CICS execution. If you have coded a value for the number of strings the pool is to use, this statistic is always less than or equal to the value you have coded. If your coded value for string numbers is consistently higher than this value in the statistics, you could consider reducing it so that your pool of VSAM strings is not bigger than you need.

 

LSRpool: Summary data buffer statistics

Summary statistics are not available online.

The group of statistics fields below summarizes the usage of each of the eight LSRPOOLS during the entire CICS run.

Table 98. LSRpool: Summary data buffer statistics
DFHSTUP name Description
Pool Number is the identifying number of the pool. This value may be in the range 1 through 8.

 

Lookasides is the total number of successful lookasides to data buffers for the pool.

 

Reads is the total number of read I/Os to the data buffers for the pool.

 

User writes is the total number of user-initiated buffer WRITEs from data buffers for the pool.

 

Non-user writes is the total number of non-user-initiated buffer WRITEs from data buffers for the pool.

 

LSRpool: Summary Hiperspace data buffer statistics

Summary statistics are not available online.

Table 99. LSRpool: Summary Hiperspace data buffer statistics
DFHSTUP name Description
Pool Number is the identifying number of the pool. This value may be in the range 1 through 8.

 

Hiperspace reads is the total number of successful CREAD requests issued to transfer data from Hiperspace data buffers to virtual data buffers.

 

Hiperspace writes is the total number of successful CWRITE requests issued to transfer data from virtual data buffers to Hiperspace data buffers.

 

Hiperspace failed reads is the total number of CREAD requests that failed. MVS had withdrawn the space and VSAM had to read data from DASD.

 

Hiperspace failed writes is the total number of CWRITE requests that failed. There was insufficient Hiperspace and VSAM had to write data to DASD.

 

LSRpool: Summary index buffer statistics

Summary statistics are not available online.

Table 100. LSRpool: Summary index buffer statistics
DFHSTUP name Description
Pool Number is the identifying number of the pool. This value may be in the range 1 through 8.

 

Lookasides is the total number of successful lookasides to index buffers for the pool.

 

Reads is the total number of read I/Os to the index buffers for the pool.

 

User writes is the total number of user-initiated buffer WRITEs from index buffers for the pool.

 

Non-user writes is the total number of non-user-initiated buffer WRITEs from index buffers for the pool.

 

LSRpool: Summary Hiperspace index buffer statistics

Summary statistics are not available online.

Table 101. LSRpool: Summary Hiperspace index buffer statistics
DFHSTUP name Description
Pool Number is the identifying number of the pool. This value may be in the range 1 through 8.

 

Hiperspace reads is the total number of successful CREAD requests issued to transfer data from Hiperspace index buffers to virtual index buffers.

 

Hiperspace writes is the total number of successful CWRITE requests issued to transfer data from virtual index buffers to Hiperspace index buffers.

 

Hiperspace failed reads is the total number of CREAD requests that failed. MVS had withdrawn the space and VSAM had to read data from DASD.

 

Hiperspace failed writes is the total number of CWRITE requests that failed. There was insufficient Hiperspace and VSAM had to write data to DASD.

 

If LSRpool buffers are shared, the statistics that follow refer to those shared data and index buffers.

LSRpool: Summary buffer statistics

Summary statistics are not available online.

Table 102. LSRpool: Summary buffer statistics
DFHSTUP name Description
Pool Number is the identifying number of the pool. This value may be in the range 1 through 8.

 

Lookasides is the total number of read requests that VSAM was able to satisfy without initiating an I/O operation; that is, the requested record, whether index or data, was already present in one of the buffer resident CIs. This means that no physical I/O had to be done to put the control interval in the buffer.

The tuning methodology usually employed involves either increasing the number of buffers of a particular CI size until the ratio of lookasides to READs stops increasing significantly or, conversely, reducing the number of buffers until the ratio of lookasides to READs begins to drop significantly. For most data sets, successful lookaside hits on indexes are more likely.

These statistics are obtained from VSAM and represent the activity after the pool was created. Note that these statistics are not reset by CICS under any circumstances.

 

Reads is the total number of I/O operations to the buffers that VSAM was required to initiate to satisfy the CICS application’s activity. This figure represents failures to find the control interval in the buffers.

These statistics are obtained from VSAM and represent the activity after the pool was created. Note that these statistics are not reset by CICS under any circumstances.

 

User writes is the total number of user-initiated I/O WRITE operations from the buffers that VSAM was required to initiate to satisfy the CICS application’s activity.

These statistics are obtained from VSAM and represent the activity after the pool was created. Note that these statistics are not reset by CICS under any circumstances.

 

Non-user writes is the total number of non-user initiated I/O WRITE operations from the buffers that VSAM was forced to initiate due to no buffers being available for reading the contents of a CI.

These statistics are obtained from VSAM and represent the activity after the pool was created. Note that these statistics are not reset by CICS under any circumstances.

 

LSRpool: Summary Hiperspace buffer statistics

Summary statistics are not available online.

Table 103. LSRpool: Summary Hiperspace buffer statistics
DFHSTUP name Description
Pool Number is the identifying number of the pool. This value may be in the range 1 through 8.

 

Hiperspace reads is the total number of successful CREAD requests issued to transfer data from Hiperspace buffers to virtual buffers.

 

Hiperspace writes is the total number of successful CWRITE requests issued to transfer data from virtual buffers to Hiperspace buffers.

 

Hiperspace failed reads is the total number of CREAD requests that failed. MVS had withdrawn the space and VSAM had to read data from DASD.

 

Hiperspace failed writes is the total number of CWRITE requests that failed. There was insufficient Hiperspace and VSAM had to write data to DASD.

The above Hiperspace statistics are obtained from VSAM and represent the activity after the pool was created. Note that these statistics are not reset by CICS under any circumstances.

 

The following information describes the buffer usage for each file that was specified to use the LSRpool at the time the statistics were printed. Note that this section is not printed for unsolicited statistics output.

If the allocation of files to the LSRpool is changed during the period that the statistics cover, no history of this is available and only the current list of files sharing the pool are printed in this section. The activity of all files that have used the pool are, however, included in all the preceding sections of these statistics.

LSRpool: Files -- Resource statistics for each file specified to use the pool

Table 104. LSRpool: Files -- Resource statistics for each file specified to use the pool
DFHSTUP name Field name Description
Pool Number A09SRPID is the LSRpool number, in the range 1 through 8, associated with this file.

Reset characteristic: not reset

 

File Name A09DSID is the CICS file identifier you specified through resource definition online.

Reset characteristic: not reset

 

Data Buff Size A09DBN is the buffer size used for the file’s data records. This value is one of the eleven possible VSAM buffer sizes ranging from 512 bytes to 32 KB. The value is zero if the file has not been opened yet.

Reset characteristic: not reset

 

Index Buff Size A09IBN is the buffer size used for the file’s index records. This is printed, even if the file has subsequently been dynamically allocated to a VSAM RRDS. The values this field may take are the same as for the data buffer size statistic.

Reset characteristic: not reset

 

Total Buff Waits A09TBW is the number of requests that had to wait because all buffers of the size used by the data set for data (or index) in the LSRpool were in use.

Reset characteristic: reset to zero

 

Peak Buff Waits A09HBW is the peak number of requests that had to wait because all buffers of the size used by the data set for data (or index) in the LSRpool were in use.

If the data sets are waiting for buffers you should examine the numbers of buffers defined for the data and index buffer sizes used by the data set. The buffer size used by VSAM depends on the control interval size in the VSAM definition of the data set. If no buffer size exists for the specified control interval size, the next largest buffer size available is used.

Reset characteristic: reset to current value

 

LSRpool: Files -- Summary resource statistics

Summary statistics are not available online.

Table 105. LSRpool: Files -- Summary resource statistics
DFHSTUP name Description
Pool Number is the LSRpool number, in the range 1 through 8, associated with this file.

 

File Name is the CICS file identifier you specified through resource definition online.

 

Data Buff Size is the last non-zero value encountered for the buffer size used for the file’s data records. This value is one of the eleven possible VSAM buffer sizes ranging from 512 bytes to 32 KB. The value is zero if the file has not been opened yet. The last non-zero value is produced only if it has been opened.

 

Index Buff Size is the last non-zero value encountered for the buffer size used for the file’s index records. This is printed, even if the file has subsequently been dynamically allocated to a VSAM RRDS. The values this field may take are the same as for the data buffer size statistic.

 

Total Buff Waits is the total number of requests that had to wait because all buffers of the size used by the data set for data (or index) in the LSRpool were in use.

 

Peak Buff Waits is the peak number of requests that had to wait because all buffers of the size used by the data set for data (or index) in the LSRpool were in use.

If the data sets are waiting for buffers you should examine the numbers of buffers defined for the data and index buffer sizes used by the data set. The buffer size used by VSAM depends on the control interval size in the VSAM definition of the data set. If no buffer size exists for the specified control interval size, the next largest buffer size available is used.

 

Related reference
Back to full list of statistics and DFHSTUP reports
Appendix A. CICS statistics tables
Interpreting these statistics
Interpreting LSRpool statistics
DFH0STAT reports for these statistics
LSRpools Report
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