LSRpools Report

Figure 116 shows the format of the LSRpools Report. This report is produced using the EXEC CICS® COLLECT STATISTICS LSRPOOL command. The statistics data is mapped by the DFHA08DS DSECT. The field headings and contents are described in Table 240. Note that if you have combined data and index buffers, the report presents the statistics for data buffers and index buffers together as "Data and Index Buffer Statistics". If you have separate data and index buffers, the report presents the statistics separately, as "Data Buffer Statistics" and "Index Buffer Statistics".

Figure 116. The LSRpools Report
Applid IYK2Z1V2  Sysid CJB2  Jobname CI07CJB23   Date 12/17/2004  Time 10:03:21       CICS 6.4.0     PAGE     2
 
 
LSR Pools
 
  Pool Number :   1          Time Created :   10:02:30.97975
 
     Maximum key length . . . . . . . :          50
     Total number of strings  . . . . :          14
     Peak concurrently active strings :           1
     Total requests waited for string :           0
     Peak requests waited for string. :           0
 
  Buffer Totals
 
     Data Buffers . . . . . . . . . . :          42                  Index Buffers. . . . . . . . . . :            0
     Hiperspace Data Buffers. . . . . :           0                  Hiperspace Index Buffers . . . . :            0
       Successful look asides . . . . :           9                   Successful look asides . . . . :             0
       Buffer reads . . . . . . . . . :          11                   Buffer reads . . . . . . . . . :             0
       User initiated writes. . . . . :           0                   User initiated writes. . . . . :             0
       Non-user initiated writes. . . :           0                   Non-user initiated writes. . . :             0
       Successful Hiperspace CREADS . :           0                   Successful Hiperspace CREADS . :             0
       Successful Hiperspace CWRITES. :           0                   Successful Hiperspace CWRITES. :             0
       Failing Hiperspace CREADS. . . :           0                   Failing Hiperspace CREADS. . . :             0
       Failing Hiperspace CWRITES . . :           0                   Failing Hiperspace CWRITES . . :             0
 
  Data and Index Buffer Statistics 

Buffer    No. of  Hiperspace   Look  Buffer   User    Non-User  Look-Aside  Successful          Failing
 Size     Buffers   Buffers  Asides  Reads    Writes  Writes    Ratio       CREADS/CWRITES   CREADS/CWRITES

   512       8          0          5        4        0        0       55.5%         0           0
  1024       4          0          0        0        0        0        0.0%         0           0
  2048       8          0          0        6        0        0        0.0%         0           0
  4096       3          0          0        0        0        0        0.0%         0           0
  8192       8          0          0        0        0        0        0.0%         0           0
 20480       5          0          4        1        0        0       80.0%         0           0
 28672       3          0          0        0        0        0        0.0%         0           0
 32768       3          0          0        0        0        0        0.0%         0           0
 
  
Table 240. Fields in the LSRpools Report
Field Heading Description
Pool Number The identifying number of the LSRpool. This value may be in the range 1 through 8.
Time Created The time when this LSRpool was created.

Source field: A08LBKCD

Maximum key length The length of the largest key of a VSAM data set which may use this LSRpool.

Source field: A08BKKYL

Total number of strings The total number of VSAM strings defined for this LSRpool.

Source field: A08BKSTN

Peak concurrently active strings 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.

Source field: A08BKHAS

Total requests waited for strings 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.

Source field: A08BKTSW

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

Source field: A08BKHSW

Data Buffers The number of data buffers specified for the LSRpool.

Source field: A08TDBFN

Hiperspace™ Data Buffers The number of Hiperspace data buffers specified for the LSRpool.

Source field: A08TDHBW

Successful look asides The number of successful lookasides to data buffers for this LSRpool.

Source field: A08TDBFF

Buffer reads The number of read I/Os to the data buffers for this LSRpool.

Source field: A08TDFRD

User initiated writes The number of user-initiated I/O writes from the data buffers for this LSRpool.

Source field: A08TDUIW

Non-user initiated writes The number of non-user-initiated I/O writes from the data buffers for this LSRpool.

Source field: A08TDNUW

Successful Hiperspace CREADS The number of successful CREAD requests issued to transfer data from Hiperspace data buffers to virtual data buffers.

Source field: A08TDCRS

Successful Hiperspace CWRITES The number of successful CWRITE requests issued to transfer data from virtual data buffers to Hiperspace data buffers.

Source field: A08TDCWS

Failing Hiperspace CREADS The number of CREAD requests that failed. MVS™ had withdrawn the space and VSAM had to read data from DASD.

Source field: A08TDCRF

Failing Hiperspace CWRITES The number of CWRITE requests that failed. There was insufficient Hiperspace and VSAM had to write the data to DASD.

Source field: A08TDCWF

Index Buffers The number of index buffers specified for the LSRpool.

Source field: A08TIBFN

Hiperspace Index Buffers The number of Hiperspace index buffers specified for the LSRpool.

Source field: A08TIHBW

Successful look asides The number of successful lookasides to index buffers for this LSRpool.

Source field: A08TIBFF

Buffer reads The number of read I/Os to the index buffers for this LSRpool.

Source field: A08TIFRD

User initiated writes The number of user-initiated buffer writes from the index buffers for this LSRpool.

Source field: A08TIUIW

Non-user initiated writes The number of non-user-initiated buffer writes from the index buffers for this LSRpool.

Source field: A08TINUW

Successful Hiperspace CREADS The number of successful CREAD requests issued to transfer data from Hiperspace index buffers to virtual index buffers.

Source field: A08TICRS

Successful Hiperspace CWRITES The number of successful CWRITE requests issued to transfer data from virtual index buffers to Hiperspace index buffers.

Source field: A08TICWS

Failing Hiperspace CREADS The number of CREAD requests that failed. MVS had withdrawn the space and VSAM had to read index data from DASD.

Source field: A08TICRF

Failing Hiperspace CWRITES The number of CWRITE requests that failed. There was insufficient Hiperspace and VSAM had to write the index data to DASD.

Source field: A08TICWF

Buffer Size The size of the data buffers that are available to CICS.

Source field: A08BKBSZ

No. of Buffers The number of buffers of each size available to CICS.

Source field: A08BKBFN

Hiperspace Buffers The number of Hiperspace buffers specified for the pool.

Source field: A08BKHBN

Look Asides 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.

Source field: A08BKBFF

Buffer Reads 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.

Source field: A08BKFRD

User Writes 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.

Source field: A08BKUIW

Non-User Writes 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.

Source field: A08BKNUW

Look-Aside Ratio The ratio of buffer look asides to buffer reads.

Source field:

((A08BKBFF / (A08BKBFF + A08BKFRD)) * 100)
Successful CREADS/ CWRITES The number of successful CREAD requests issued to transfer data from Hiperspace buffers to virtual buffers, and of successful CWRITE requests issued to transfer data from virtual buffers to Hiperspace buffers.

Source field: A08BKCRS + A08BKCWS

Failing CREADS/ CWRITES The number of CREAD requests that failed (because MVS had withdrawn the space and VSAM had to read data from DASD), and the number of CWRITE requests that failed (because there was insufficient Hiperspace and VSAM had to write the data to DASD).

Source field: A08BKCRF + A08BKCWF

Buffer Size The size of the index data buffers that are available to CICS.

Source field: A08IKBSZ

No. of Buffers The number of buffers of each size available to CICS.

Source field: A08IKBFN

Hiperspace Buffers The number of Hiperspace buffers specified for the pool.

Source field: A08IKHBN

Look Asides The number of read requests that VSAM was able to satisfy without initiating an I/O operation; that is, the requested index record 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.

Source field: A08IKBFF

Buffer Reads 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.

Source field: A08IKFRD

User Writes 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.

Source field: A08IKUIW

Non-User Writes 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.

Source field: A08IKNUW

Look-Aside Ratio The ratio of buffer look asides to buffer reads.

Source field: ((A08BKBFF / (A08BKBFF + A08BKFRD)) * 100)

Successful CREADS/ CWRITES The number of successful CREAD requests issued to transfer data from Hiperspace buffers to virtual buffers, and of successful CWRITE requests issued to transfer data from virtual buffers to Hiperspace buffers.

Source field: A08IKCRS + A08IKCWS

Failing CREADS/ CWRITES The number of CREAD requests that failed (because MVS had withdrawn the space and VSAM had to read data from DASD), and the number of CWRITE requests that failed (because there was insufficient Hiperspace and VSAM had to write the data to DASD).

Source field: A08IKCRF + A08IKCWF

Related reference
Back to full list of DFH0STAT reports
The DFH0STAT reports
Interpreting these statistics
Interpreting LSRpool statistics
Full listing and DFHSTUP reports for these statistics
LSRpool statistics

[[ Contents Previous Page | Next Page Index ]]