CICS® supports the use of up to eight LSRpools, and produces two sets of statistics for LSRpool activity.
This section contains the following statistics:
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.
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:
Reset characteristic: not reset
|
Total number of strings | A08BKSTN | is the value obtained from one of:
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.
DFHSTUP name | Field name | Description |
---|---|---|
Size | A08BKBSZ | is the size of the buffers that are available to CICS. Buffers may
be specified through:
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
|
DFHSTUP name | Field name | Description |
---|---|---|
Size | A08BKBSZ | is the size of the buffers that are available to CICS. Buffers may
be specified through:
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
|
DFHSTUP name | Field name | Description |
---|---|---|
Size | A08BKBSZ | is the size of the buffers that are available to CICS. Buffers may
be specified through:
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
|
DFHSTUP name | Field name | Description |
---|---|---|
Size | A08BKBSZ | is the size of the buffers that are available to CICS. Buffers may
be specified through:
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.
DFHSTUP name | Field name | Description |
---|---|---|
Buffer Size | A08BKBSZ | is the size of the buffers that are available to CICS. Buffers may
be specified through:
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
|
DFHSTUP name | Field name | Description |
---|---|---|
Size | A08BKBSZ | is the size of the buffers that are available to CICS. Buffers may
be specified through:
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.
|
Summary statistics are not available online.
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.
|
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.
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.
|
Summary statistics are not available online.
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.
|
Summary statistics are not available online.
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.
|
Summary statistics are not available online.
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.
Summary statistics are not available online.
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.
|
Summary statistics are not available online.
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.
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
|
Summary statistics are not available online.
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.
|