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".
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
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 |