The dynamic storage areas

The dynamic storage areas are used to supply CICS® tasks with the storage needed to execute your transactions. From the storage size that you specify on the DSALIM and the EDSALIM parameters, CICS allocates the dynamic storage areas above and below the line respectively.

Too small a dynamic storage area results in increased program compression or, more seriously, SOS (short on storage) conditions, or even storage deadlock abends when program compression is not sufficient.

DSAs consist of one or more extents. An extent below the line is 256KB and above the line, 1MB (except UDSA with TRANISO active, when the extent is 1M).

CICS GETMAIN requests for dynamic storage are satisfied from one of the following: the CDSA, UDSA, SDSA, ECDSA, , EUDSA, or the ESDSA during normal execution. The sizes of the dynamic storage areas are defined at CICS initialization, but the use of storage within them is very dynamic.

The dynamic storage areas consist of a whole number of virtual storage pages allocated from a number of MVS™ storage subpools. CICS uses about 180 storage subpools, which are located in the dynamic storage areas. For a list of the subpools see the tables in topics Table 255 through Table 260. Each dynamic storage area has it own "storage cushion" These subpools (including the cushion) are dynamically acquired, as needed, a page at a time, from within the dynamic storage area.

The dynamic storage areas are essential for CICS operation. Their requirements depend on many variables, because of the number of subpools. The major contributors to the requirements are program working storage and the type and number of program and terminal definitions. The storage used by individual subpools can be determined by examining the CICS domain subpool statistics (storage manager statistics).

If you have exhausted the tuning possibilities of MVS/ESA and other tuning possibilities outside CICS, and the dynamic storage areas limits have been set as large as possible within CICS, and you are still encountering virtual storage constraint below 16MB, you may have to revise the use of options such as MXT and making programs resident, to keep down the overall storage requirement. This may limit task throughput. If you foresee this problem on an MVS system, you should consider ways of dividing your CICS system, possibly by use of facilities such as CICS multiregion operation (MRO), described in the CICS Intercommunication Guide. You can also reduce storage constraint below 16MB by using programs which run above 16MB.

In systems with a moderate proportion of loadable programs, program compression is an indicator of pressure on virtual storage. The pressure on virtual storage can be determined by examining the CICS storage manager statistics which report the number of times that CICS went short on storage.

If the dynamic storage areas limits are too small, CICS performance is degraded. The system may periodically enter a short-on-storage condition, during which it curtails system activity until it can recover enough storage to resume normal operations.

However, resist the temptation to make the dynamic storage area limit as large as possible (which you could do by specifying the maximum allowable region size). If you do this, it can remove any warning of a shortage of virtual storage until the problem becomes intractable.

The dynamic storage areas limits should be as large as possible after due consideration of other areas, especially the MVS storage area above 16MB.

CICS subpools

This section describes briefly the main features of the subpools. They are found in each of the dynamic storage areas. Most of the subpools are placed above the 16MB line. Those subpools that are found below the 16MB line, in the CDSA, SDSA, RDSA, and UDSA, need to be more carefully monitored due to the limited space available. Individual subpools may be static or dynamic. Some contain static CICS storage which cannot be tuned. All the subpools are rounded up to a multiple of 4KB in storage size and this rounding factor should be included in any subpool sizing or evaluation of storage size changes due to tuning or other changes. CICS statistics contain useful information about the size and use of the dynamic storage area subpools. The CICS subpools in the dynamic storage areas may be grouped and described according to the major factor affecting their use.

Application design
The use of CICS facilities such as program LINK, SHARED storage GETMAINs, the type of file requests, use of temporary storage, application program attributes (resident or dynamic), or the number of concurrent DBCTL, or DB2®, requests affect storage requirements.
Number of files definitions
These subpools may only be tuned by reducing the number of file definitions, or by using MRO.
The use of DBCTL, or DB2
These subpools are only present if DBCTL or DB2 is used. The subpools may be tuned by reducing the number of threads, or by using maximum tasks (MXT) or transaction classes.
Nucleus and macro table storage
It may be possible to reduce the macro table storage by reducing the number of macro definitions or by migrating selected macro-defined tables to RDO.
Number and type of terminal definitions
The OPNDLIM system initialization parameter may also be tuned to limit storage use.

The following tables list the subpools according to their dynamic storage areas and their use.

CICS subpools in the CDSA

Table 255. CICS subpools in the CDSA
Subpool name Description
AP_TCA24 contains the TCA when the task data location option is set to Start of changeBELOWEnd of change
DFHAPD24 is a general subpool for application domain storage below the line.
DFHTDG24 CXRE queue definitions and SDSCI are allocated from this subpool.
DFHTDSDS contains real transient data SDSCIs, each of which contains a DCB which resides below the line.
DHPDPOOL contains DCBs for partitioned data sets used by document handler domain
FC_DCB contains the DCBs for BDAM files. Each file that is defined requires 104 bytes.
FCCBELOW contains real VSWA and data buffers for pre-reads. Each VSWA requires 120 bytes of storage. The maximum number of data buffers for pre-reads is given by:

(number of strings) x (maximum record length) x (number of files).

KESTK24 2KB below the line kernel stack. One per MXT plus one for every dynamic system task that is running.
KESTK24E 4KB below the line kernel stack extension. At least one of these for every ten tasks specified in the MXT limit.
LDNRS contains the CICS nucleus and macro tables, which are RESIDENT. The CICS nucleus is approximately 192KB and the size of the tables can be calculated. Programs defined EXECKEY (CICS) and link edited RMODE(24) without the reentrant open.
LDNUC contains the CICS nucleus and macro tables, which are not RESIDENT. The CICS nucleus is approximately 192KB and the size of the tables can be calculated. Programs defined EXECKEY (CICS) and link edited RMODE(24) without the reentrant open.
SMCONTRL satisfies GETMAINs for control class storage.
SMSHARED contains shared storage below the 16MB line, for example RMI global work areas, EDF blocks for the life of the transaction being monitored, and other control blocks.
SMSHRC24 is used for many control blocks of SHARED_CICS24 class storage.
SMTP24 holds line and terminal I/O areas which cannot be located above the 16MB line. The storage requirements depend on the amount of terminal and line traffic in the system. The subpool may be tuned by reducing the RAPOOL, RAMAX, TIOAL size, and number of MRO sessions.
SZSPFCAC contains the FEPI VTAM® ACB work areas.
TRUBELOW contains task-related user exit pool below the 16 MB line.
XMGEN24 contains general storage used by transaction manager
ZCSETB24 contains application control buffers below the line.
ZCTCTUA contains the TCTTE user area. It can be located in one of the following DSAs: SDSA, ECDSA, CDSA, or ESDSA. Its location is controlled by the system initialization parameter, TCTUALOC=ANY|BELOW and the system initialization parameter, TCTUAKEY=CICS|USER. The maximum size can be specified in USERAREALEN operand of the terminal definition. See the CICS Resource Definition Guide for more information about the terminal definition.

CICS subpools in the SDSA

Table 256. CICS subpools in the SDSA
Subpool name Description
APECA contains the event control areas.
DFHAPU24 is a general subpool for application domain storage below the line.
LDPGM contains dynamically loaded application programs (RMODE (24)). The expected size of this subpool may be predicted from previous releases, and by taking LDPGMRO into account. The subpool size may be reduced by using 31-bit programs. Not reentrant.
LDRES contains resident application programs (RMODE (24). The expected size of this subpool may be predicted from previous releases, and by taking LDRESRO into account. The subpool size may be reduced by using 31-bit programs. Not reentrant.
OSCOBOL is used for the allocation of the COBOL merged load list (MLL) control block and its extents. It should never occupy more than its initial allocation of one page of storage.
SMSHRU24 is used for many control blocks of SHARED_USER24 class storage.
ZCTCTUA contains the TCTTE user area. It can be located in one of the following DSAs: SDSA, ECDSA, CDSA, or ESDSA. Its location is controlled by the system initialization parameter, TCTUALOC=ANY|BELOW and the system initialization parameter, TCTUAKEY=CICS|USER. The maximum size can be specified in USERAREALEN operand of the terminal definition. See the CICS Resource Definition Guide for more information about the terminal definition.

CICS subpools in the RDSA

Table 257. CICS subpools in the RDSA
Subpool name Description
LDNRSRO contains programs defined EXECKEY(CICS) which are RESIDENT, that were link edited REENTRANT and RMODE(24).
LDNUCRO contains programs defined EXECKEY(CICS) which are not RESIDENT, that were link edited REENTRANT and RMODE(24).
LDPGMRO contains programs defined EXECKEY(USER) which are not RESIDENT, that were link edited RMODE(24) and REENTRANT.
LDRESRO contains programs defined EXECKEY(USER) and RESIDENT and were link edited REENTRANT and RMODE(24).

CICS subpools in the ECDSA

Table 258. CICS subpools in the ECDSA
Subpool name Description
>LGJMC log manager domain - journal model resource entries
AITM_TAB is the autoinstall terminal model (AITM) table entry subpool (DFHAITDS).
AP_TCA31 contains the Start of changeTCA when the task data location option is set to ANYEnd of change
AP_TXDEX contains the application part of the TXD table
APAID31 contains storage for AIDs above the line.
APBMS contains storage use by BMS.
APCOMM31 contains COMMAREAs. The storage requirement depends on the size of COMMAREA specified and the number of concurrent users of the application.
APDWE contains non-task deferred work elements
APICE31 contains storage for ICEs above the line.
APURD subpool contains URDs and nontask DWEs.
ASYNCBUF contains buffers used by asynchronous operations in the sockets domain
BAGENRAL general purpose subpool for business application manager domain
BAOFBUSG contains buffer storage used by business application manager domain
BAOFT_ST contains storage used by activities in business application manager domain
BR_BSB contains bridge start blocks
BRGENRAL general purpose subpool used by the bridge
BRPC contains storage used for bridge primary clients
BRVS contains storage used for bridge virtual terminals
BRVSCA contains storage used for bridge virtual screen character attributes
BRVSXA contains storage used for bridge virtual screen extended attributes
DBCTL subpool contains the TIE blocks for RMI use, when invoked by the DBCTL task-related user exit program, DFHDBAT. The tie is 120 bytes long, and appended to the tie is the local task work area for this task-related user exit which is, for DFHDBAT, 668 bytes long. This subpool is present only when DBCTL is used. It may be tuned by limiting DBCTL threads or using maximum tasks (MXT) or transaction classes.
DBDBG contains DBCTL global blocks
DCTE_EXT contains all extrapartition queue definitions.
DCTE_IND contains all indirect queue definitions.
DCTE_INT contains all intrapartition queue definitions.
DCTE_REM contains all remote queue definitions.
DDBROWSE contains storage for directory manager browse request tokens.
DDGENRAL contains directory manager control blocks general information.
DDS_DCTE contains storage for directory manager directory elements for the DCTE table.
DDS_DHT1 contains storage for directory manager directory elements for the DHT1 table.
DDS_DHT2 contains storage for directory manager directory elements for the DHT2 table.
DDS_D2CS contains storage for directory manager directory elements for the D2CS table.
DDS_D2EN contains storage for directory manager directory elements for the D2EN table.
DDS_D2TN contains storage for directory manager directory elements for the D2TN table.
DDS_D2TT contains storage for directory manager directory elements for the D2TT table.
DDS_NQRN contains storage for directory manager directory elements for the NQRN table.
DDS_PPT contains storage for directory manager directory elements for the PPT table.
DDS_PTT contains storage for directory manager directory elements for the PTT table.
DDS_RTXD contains storage for directory manager directory elements for the RTXD table.
DDS_TCL contains storage for directory manager directory elements for the TCL table.
DDS_TPNM contains storage for directory manager directory elements for the TPNM table.
DDS_TXD contains storage for directory manager directory elements for the TXD table.
DDS_USD1 contains storage for directory manager directory elements for the USD1 table.
DDS_USD2 contains storage for directory manager directory elements for the USD2.
DDS_WBST contains storage for directory manager directory elements for the WBST table.
DFHAPDAN is a general subpool for application domain storage above the line.
DFHD2CSB contains control blocks representing DB2 threads created by the CICS/DB2 adapter
DFHD2ENT contains control blocks representing DB2ENTRY definitions
DFHD2TRN contains control blocks representing DB2TRAN definitions
DFHTDG31 contains transient data general storage and control blocks. The storage requirement depends on the number of buffers and strings, and on the control interval size specified.
DFHTDIOB contains intrapartition transient data input/output buffers. The storage requirement is given by the control interval size of the intrapartition transient data set multiplied by the number of buffers.
DFHTDWCB contains the transient data wait elements.
DHDBB contains document bookmark blocks.
DHDCR contains document control records.
DHDDB contains document data.
DHDOA contains document anchor blocks.
DHGENRAL The general purpose subpool for the document manager domain.
DHSTB contains document symbol tables.
DHTLPOOL contains document handler template descriptors.
DLI subpool contains the TIE blocks for RMI use, when invoked by the EXEC DL/I task-related user exit program, DFHEDP. The tie is 120 bytes long, and appended to the tie is the local task work area for this task-related user exit which is, for DFHEDP, 4 bytes long. This subpool is only present when EXEC DL/I is used. It may be tuned by limiting DBCTL threads or using maximum tasks (MXT) or transaction classes.
DMSUBPOL is the domain manager subpool for general usage.
DS_STIMR contains dispatcher domain STIMER tokens
DS_TCB contains dispatcher domain TCBs
DS_VAR dispatcher domain variable length subpool
DSBROWSE contains storage for dispatcher browse request tokens.
EJMI enterprise bean method information
EJOSGENS enterprise bean general subpool
EJOSTSKS enterprise bean task subpool
EJSPBFBC contains browser control blocks for enterprise beans
EJSPBVIC contains enterprise bean control blocks
EJSPCFBC contains browser control blocks for CorbaServers
EJSPCFIC contains control blocks for CorbaServers
EJSPCOMM contains anchor blocks for enterprise beans
EJSPDFBC contains browser control blocks for deployed JAR files
EJSPDFIC contains control blocks for deployed JAR files
EJSPGVNC contains persistent storage for enterprise beans
EJSPTVNC contains transaction-related storage for enterprise beans
EJSTGENS contains control blocks for enterprise bean statistics
EMBRB contains event manager browse blocks
EMEVA contains the event manager event pool anchor
EMEVB contains event manager event blocks
EMGENRAL general purpose subpool for event manager domain
FC_ABOVE contains real VSWA and data buffers for pre-reads. Each VSWA requires 120 bytes of storage. The maximum number of data buffers for pre-reads is given by:

(number of strings) x (maximum record length) x (number of files)

FC_ACB contains ACBs for VSAM files. There is one ACB, of 80 bytes, per VSAM file.
FC_BDAM BDAM file control blocks. Each BDAM file requires 96 bytes of storage.
FC_DSNAM contains data set name blocks. Each file requires a data set name block which uses 120 bytes of storage.
FC_FCPE contains file control pool elements
FC_FCPW contains file control CFDT pool wait elements
FC_FCUP contains the file control CFDT unit of work pool block
FC_FLAB contains file control lasting access blocks
FC_FLLB contains file control lock locator blocks
FC_FRAB contains file request anchor blocks (FRABs). There is one FRAB for each transaction that has issued a file control request. The FRAB is retained until the end of the task. There is a free chain of FRABs not currently in use.
FC_FRTE contains file request thread elements (FRTE). There is one FRTE for each active file control request per task. A file control request has a FRTE if:
  • It has not yet terminated its VSAM thread. For example, a browse that has not yet issued an ENDBR.
  • It has updated a recoverable file and there has not yet been a syncpoint.
  • It is holding READ-SET storage that must be freed in future.

There is a free chain of FRTEs not currently in use.

FC_RPL contains file control's request parameter lists
FC_SHRCT contains file control SHRCTL blocks. There are eight of these and each describes a VSAM LSR pool.
FC_VSAM contains the file control table (FCT) entries for VSAM files.
FCB_256 contains file control buffers of length 256 bytes. They are used by file control requests that are made against files whose maximum record length is less than or equal to 256 bytes.
FCB_512 contains file control buffers of length 512 bytes. They are used by file control requests that are made against files whose maximum record length is between 256 bytes+1 byte up to 512 bytes.
FCB_1K contains file control buffers of length 1KB. They are used by file control requests that are made against files whose maximum record length is between 512 bytes+1 byte up to 1KB.
FCB_2K contains file control buffers of length 2KB. They are used by file control requests that are made against files whose maximum record length is between 1KB+ 1 byte up to 2KB.
FCB_4K contains file control buffers of length 4KB. They are used by file control requests that are made against files whose maximum record length is between 2KB+1 byte up to 4KB.
FCB_8K contains file control buffers of length 8KB. They are used by file control requests that are made against files whose maximum record length is between 4KB+1 byte up to 8KB.
FCB_16K contains file control buffers of length 16KB. They are used by file control requests that are made against files whose maximum record length is between 8KB+1 byte up to 16KB.
FCB_32K contains file control buffers of length 32KB. They are used by file control requests that are made against files whose maximum record length is between 16KB+1 byte up to 32KB.
FCB_64K contains file control buffers of length 64KB. They are used by file control requests that are made against files whose maximum record length is between 32KB+1 byte up to 64KB.
FCB_128K contains file control buffers of length 128KB. They are used by file control requests that are made against files whose maximum record length is between 64KB+1 byte up to 128KB.
FCB_256K contains file control buffers of length 256KB. They are used by file control requests that are made against files whose maximum record length is between 128KB+1 byte up to 256KB.
FCB_512K contains file control buffers of length 512KB. They are used by file control requests that are made against files whose maximum record length is between 256KB+1 byte up to 512KB.
FCB_1M contains file control buffers of length 1MB. They are used by file control requests that are made against files whose maximum record length is between 512KB+1 byte up to 1MB.
FCB_2M contains file control buffers of length 2MB. They are used by file control requests that are made against files whose maximum record length is between 1MB+ 1 byte up to 2MB.
FCB_4M contains file control buffers of length 4MB. They are used by file control requests that are made against files whose maximum record length is between 2MB+1 byte up to 4MB.
FCB_8M contains file control buffers of length 8MB. They are used by file control requests that are made against files whose maximum record length is between 4MB+1 byte up to 8MB.
FCB_16M contains file control buffers of length 16KB. They are used by file control requests that are made against files whose maximum record length is between 8MB+1 byte up to 16MB.
IFGLUWID VSAM IFGLUWID area
IIBUFFER IIOP domain buffer subpool
IIGENRAL IIOP domain general subpool
IIMBR IIOP domain request model browse block
IIMDB IIOP domain request model block
KESTK31 24KB above the line kernel stack. One per MXT plus one for every dynamic system task that is running.
KESTK31E 4KB above the line kernel stack extensions. At least one for every ten tasks specified in the MXT limit.
KETASK kernel task entries.
L2GENRAL log manager domain general subpool
L2OFL2BL log manager domain - logger block entries.
L2OFL2BS log manager domain - logger browseable stream objects.
L2OFL2CH log manager domain - logger chain objects.
L2OFL2SR log manager domain - logger stream objects.
LD_APES loader domain - active program elements.
LD_CDE loader domain - dummy CDEs
LD_CPES loader domain - quick cell subpool
LD_CNTRL loader domain - general control information.
LD_CSECT loader domain - CSECT list storage.
LDENRS contains the extended CICS nucleus, and 31-bit macro tables, which are RESIDENT. The extended CICS nucleus is approximately 50KB. Programs defined EXECKEY(CICS) and link edited RMODE(ANY) without the REENTRANT option.
LDENUC contains the extended CICS nucleus, and 31-bit macro tables, which are not RESIDENT. The extended CICS nucleus is approximately 50KB. Programs defined EXECKEY(CICS) and link edited RMODE(ANY) without the REENTRANT option.
LGBD log manager domain - log stream name/journal name/journal model browse tokens.
LGGD log manager domain - explicitly opened general logs.
LGGENRAL general purpose subpool for log manager domain.
LGJI log manager domain - journal name entries.
LGSD log manager domain - log stream data entries.
LGUOW log manager domain - unit of work data entries.
LI_PLB language interface - program language block. One is allocated for each program when control is first passed to it.
MDTTABLE MDT field attribute table for BMS maps sent through the CICS Web interface.
MN_CNTRL contains monitoring control blocks - general information.
MN_TMAS contains monitoring control blocks. The storage requirement is 2088 bytes per active task. However, you might have to increase the number of bytes depending on your MCT settings.
MRO_QUEU is used by the MRO work queue manager.
MROWORKE is used by the MRO work queue manager elements.
NQEAS contains NQ domain queue element areas
NQGENRAL general subpool used by NQ domain
NQPOOL contains NQ domain enqueue pools
NQRNAMES contains NQRN directory entries
OTGENRAL general subpool used by OT domain
OTISINST contains inflight state of OTS transactions
Start of changePGCHCBEnd of change Start of changestorage for channel control blocks. This contains header information describing a channel.End of change
Start of changePGCPCBEnd of change Start of changestorage for channel container pool control block. This contains header information describing sets of containers.End of change
Start of changePGCRBBEnd of change Start of changestorage for browses of channel containersEnd of change
Start of changePGCRCBEnd of change Start of changestorage for channel container control blocks. This contains the header information for each container.End of change
Start of changePGCSCB4KEnd of change Start of changestorage for fixed-length channel container segments, including segment headers. The amount of container storage is the sum of this subpool and PGCSCBV.End of change
Start of changePGCSCBVEnd of change Start of changestorage for variable-length channel container segmentsEnd of change
PGGENRAL general purpose program manager domain subpools.
PGHMRSA program handle manager cobol register save areas.
PGHTB program manager handle table block.
PGJVMCL contains JVM class names
PGLLE program manager load list elements.
PGPGWE program manager wait elements.
PGPPTE program manager program definitions (PPTs).
PGPTA program manager transaction-related information.
PR_TABLE contains storage for PTEs from the PRT.
RMGENRAL recovery manager general subpool
RMOFRMLK contains recovery manager link objects
RMOFRMUW contains recivery manager unit of work objects
RUNTRAN transaction manager subpool for run transaction
RUTKPOOL subpool for reusable token class
RXGENRAL general subpool for RX domain
RZGENRAL general subpool for request streams domain
RZOFRSNR contains request streams notification requests
RZOFRSRG contains request streams registration objects
RZOFRZRS contains request streams objects
RZOFRZTR contains request stream transports
SHGENRAL general subpool for scheduler services domain
SHOFSHRE contains scheduler services request objects
SJGENRAL general subpool for SJVM domain
SJJ8TCB contains J8 TCBs in the SJVM domain
SMSHRC31 is used for many control blocks of SHARED_CICS31 class storage.
SMTP holds line and terminal I/O areas. The storage requirements depend on the amount of terminal and line traffic in the system. The subpool may be tuned by reducing the RAPOOL, RAMAX, TIOAL size, and number of MRO sessions.
SOCKET contains Socket objects.
SOGENRAL The sockets domain general subpool.
SOLTE contains socket domain listener terminal entries.
SOSTE contains socket domain socket terminal entries.
SOTBR contains socket domain TCPIPSERVICE browse blocks.
SOTDB contains socket domain TCPIPSERVICE blocks.
SOTKPOOL contains socket domain socket tokens.
STSUBPOL is a statistics domain manager subpool.
SZSPFCCD is the FEPI connection control subpool.
SZSPFCCM is the FEPI common area subpool.
SZSPFCCV is the FEPI conversation control subpool.
SZSPFCDS is the FEPI device support subpool.
SZSPFCNB is the FEPI node initialization block subpool.
SZSPFCND is the FEPI node definition subpool.
SZSPFCPD is the FEPI pool descriptor subpool.
SZSPFCPS is the FEPI property descriptor subpool.
SZSPFCRP is the FEPI request parameter list subpool.
SZSPFCRQ is the FEPI requests subpool.
SZSPFCSR is the FEPI surrogate subpool.
SZSPFCTD is the FEPI target descriptor subpool.
SZSPFCWE is the FEPI work element subpool.
SZSPVUDA is the FEPI data areas subpool.
TASKASOC contains sockets domain task association objects
TD_TDCUB contains all the transient data CI update control blocks.
TD_TDQUB contains all the transient data queue update control blocks.
TD_TDUA contains all the transient data UOW anchor control blocks.
TIA_POOL is the timer domain anchor subpool.
TIQCPOOL is the timer domain quickcell subpool.
TSBRB contains TS browse blocks.
TSBUFFRS contains the temporary storage I/O buffers. The storage requirement is given by:

(TS control interval size) x (number of TS buffers). The use of temporary storage by application programs affects the size of a number of subpools associated with temporary storage control blocks:

TSDTN contains TS digital tree nodes.
TSGENRAL The amount of storage used by the TSGENRAL subpool depends on the number of buffers and strings and the control interval size defined for the temporary storage data set.
TSICDATA contains TS interval control elements.
TSMAIN contains storage for temporary storage main storage. The subpool could be reduced by using auxiliary temporary storage.
TSMBR contains storage for temporary storage browse blocks
TSMDB contains storage for temporary storage model blocks
TSMN0064 contains TS main items with lengths (including the header) less than or equal to 64.
TSMN0128 contains TS main items with lengths (including the header) less than or equal to 128.
TSMN0192 contains TS main items with lengths (including the header) less than or equal to 192.
TSMN0256 contains TS main items with lengths (including the header) less than or equal to 256.
TSMN0320 contains TS main items with lengths (including the header) less than or equal to 320.
TSMN0384 contains TS main items with lengths (including the header) less than or equal to 384.
TSMN0448 contains TS main items with lengths (including the header) less than or equal to 448.
TSMN0512 contains TS main items with lengths (including the header) less than or equal to 512.
TSQAB contains TS queue anchor blocks.
TSQOB contains TS queue ownership blocks.
TSQUB contains TS queue update blocks.
TSQUEUE contains TS queue descriptors.
TSTSI contains TS item descriptors.
TSTSS contains TS section descriptors.
TSTSX contains TS auxiliary item descriptors.
TSW contains TS wait queue elements.
UE_EPBPL is the subpool for the user exit program block (EPB).
USGENRAL is the general-purpose subpool for the user domain.
USDDB contains user domain DCE data blocks
USIDTBL contains the attach security userid table entries (LUITs). See ISC/IRC attach time entry statistics for more information.
USRTMQUE contains queue elements for users waiting for USRDELAY. Each queue element is 16 bytes.
USUDB contains user data blocks. The storage requirement is 128 bytes per unique user.
USXDPOOL contains user domain transaction-related data. Each executing transaction requires 32 bytes.
WBGENRAL The general subpool for CICS Web support.
WBRQB contains web request objects.
WBWRBR contains web request browse blocks.
WEB_STA contains web state-related storage.
WEBINB contains web domain storage for incoming data.
WEB327B contains web domain 3270 buffer storage.
XMGENRAL is the general-purpose subpool for the transaction manager.
XMTCLASS contains the transaction manager tranclass definition.
XMTRANSN transaction manager transactions. One for every transaction in the system.
XMTXDINS transaction manager transaction definition.
XMTXDSTA transaction manager transaction definition.
XMTXDTPN contains the transaction manager transaction definition TPNAME storage.
XSGENRAL is the general-purpose subpool for the security domain.
XSXMPOOL contains security domain transaction-related data. Each executing transaction requires 56 bytes.
ZC2RPL contains the duplicate RPLs for active tasks. Each active task associated with a VTAM terminal requires 304 bytes.
ZCBIMG contains BIND images.
ZCBMSEXT contains the BMS extensions for terminals. Subpool storage requirements are 48 bytes for each terminal, surrogate, ISC session, and console.
ZCBUF contains the non-LU6.2 buffer list.
ZCCCE contains the console control elements. Each console requires 48 bytes.
ZCGENERL is the general-purpose subpool for terminal control.
ZCLUCBUF contains the LU6.2 SEND and RECEIVE buffer list .
ZCLUCEXT contains the LU6.2 extensions. The storage requirement is 224 bytes for each LU6.2 session.
ZCNIBD contains the NIB descriptors. Each terminal, surrogate, ISC session, and system definition requires 96 bytes of storage.
ZCNIBISC contains the expanded NIB and response during OPNDST/CLSDST for ISC. Each concurrent logon/logoff requires 448 bytes of storage. The maximum number of concurrent requests is limited by the number of sessions. The storage may be tuned by reducing the number of sessions.
ZCNIBTRM contains the expanded NIB during OPNDST/CLSDST for terminals. Each concurrent logon/logoff requires 192 bytes of storage. The maximum number of concurrent requests is limited by the number of terminals . The storage may be tuned by reducing the number of terminals.
ZCRAIA contains the RECEIVE ANY I/O areas.
ZCRPL contains the RPLs for active tasks. Each active task associated with a VTAM terminal requires 152 bytes.
ZCSETB contains application control buffers above the line.
ZCSKEL contains the remote terminal entries. Each remote terminal definition requires 32 bytes of storage.
ZCSNEX contain the TCTTE signon extensions. The storage requirement is 48 bytes for each terminal, surrogate, session, and console.
ZCTCME contains the mode entries. Each mode entry requires 128 bytes of storage.
ZCTCSE contains the system entries. Each system entry requires 192 bytes of storage.
ZCTCTTEL contains the large terminal entries. 504 bytes of storage are required for every terminal, surrogate model, and ISC session defined.
ZCTCTTEM contains the medium terminal entries. 400 bytes of storage are required for every IRC batch terminal.
ZCTCTTES contains the small terminal entries. 368 bytes of storage are required for every MRO session and console.
ZCTPEXT the TPE extension.
ZCTREST terminal control transaction restart subpool
ZCTCTUA contains the TCTTE user area. It can be located in one of the following DSAs: CDSA, SDSA, ECDSA, or ESDSA. Its location is controlled by the system initialization parameter, TCTUALOC=ANY|BELOW and the system initialization parameter, TCTUAKEY=CICS|USER. The maximum size can be specified in USERAREALEN operand of the terminal definition. See the CICS Resource Definition Guide for more information.

CICS subpools in the ESDSA

Table 259. CICS subpools in the ESDSA
Subpool name Description
LDEPGM contains extended (31) bit dynamically loaded application programs and programs defined EXECKEY(USER).
LDERES contains extended (31) bit resident application programs.
SMSHRU31 is used for many control blocks of SHARED_USER31 class storage, RMI global work areas, EDF blocks for the life of the transaction being monitored, and other control blocks.
WEBINB contains web 3270 buffer storage
ZCTCTUA contains the TCTTE user area. It can be located in one of the following DSAs: CDSA, SDSA, ECDSA, or ESDSA. Its location is controlled by the system initialization parameter, TCTUALOC=ANY|BELOW and the system initialization parameter, TCTUAKEY=CICS|USER. The maximum size can be specified in USERAREALEN operand of the terminal definition. See the CICS Resource Definition Guide for more information.

CICS subpools in the ERDSA

Table 260. CICS subpools in the ERDSA
Subpool name Description
LDENRSRO contains the extended CICS nucleus and 31-bit macro tables, which are RESIDENT. The extended CICS nucleus is approximately 1850KB. The contents of this subpool has to be linked reentrant.
LDENUCRO contains the extended CICS nucleus and 31-bit macro tables, which are not RESIDENT. The extended CICS nucleus is approximately 1850KB. The contents of this subpool has to be linked reentrant.
LDEPGMRO contains extended (31) bit dynamically loaded application programs. The contents of this subpool has to be linked reentrant.
LDERESRO contains extended (31) bit resident application programs. The contents of this subpool has to be linked reentrant.
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