IMS-Specific Environment Variables

Provides a summary description for each IMS-specific environment variable used by Enterprise Server.

This topic lists environment variables related to configuring the IMS environment in an enterprise server region.

Important: This topic provides summary descriptions only. For complete information, see corresponding variables in the Environment variables in alphabetical order topic.
Variable Description
ES_ACBLIB The location of IMS ACB files.
ES_DFS3650 The default transaction to execute or MOD file to be displayed after successfully signing on to IMS. You specify these by setting environment variables prior to the start of the region: ES_DFS3650 - set to MOD if a MOD file is to be sent, or TRX if a TRANSACTION is to be executed. If you set to MOD, ES_MOD3650 needs to be set to the name of the MOD you want to display. If you set to TRX, ES_TRX3650 needs to be set to the name of the transaction.
ES_IMS_BASIC_CHKP_OPT When set to 1, enables a basic checkpoint call to process as if a SYNC call had been issued. The default is 0 (zero).
ES_IMS_BYPASS_OTMA_DEST_RES By default, a CHNG call issued from an OTMA- or IMS Connect-submitted transaction assumes that the destination is the OTMA client. In some circumstances, the previous behavior of assuming a non-OTMA client is desirable. To use the previous behavior, set this environment variable to Y.
ES_IMS_CONFIG The IMS TM parameters.
ES_IMS_DB_COMMIT_FLUSH When set to 0 (zero), forces the flushing of database buffers to disk on CLOSE only (default). When set to 1, forces the flushing of database buffers to disk on COMMIT only.
ES_IMS_DB_TLOG_WRITETHRU When set to 0 (zero), forces the flushing of TLOG buffers to disk on COMMIT only (default). When set to 1, forces the flushing of TLOG buffers to disk on all database I/O.
ES_IMS_DEADLOCK_WAIT Time in milliseconds to wait before checking for a deadlock. The default is 1000 (1 second).
ES_IMS_DIAGNOSE Marks IMS TM as diagnose mode only for IMSMSGQ.
ES_IMS_DOSVS_PCB Emulates DOS/VSE PCB address alignment for EXEC DLI programs.
ES_IMS_DUMP_ON_DEADLOCK Creates a system dump when a deadlock is detected.
ES_IMS_DUMP_ON_TIMEOUT Creates a system dump when a lock timeout occurs.
ES_IMS_EXITPATH The location of compiled code that contains segment and/or field exits.
ES_IMS_FORCE_SIGNON Enables a user to force a sign-on to IMS on the current terminal and sign off from other terminals.
ES_IMS_GOTO_CICS_ON_SIGNOFF Returns to CICS upon logging off or timing out, rather than returning to the IMS sign-on screen, which is the default behavior.
ES_IMS_IBMPLATFORM Sets the emulation for the IMS run-time. Valid values are: M (for MVS) or D (for DOSVS). The default value is M.
Note: This variable is rarely required to be changed from its default, even for the majority of DOSVS users.
ES_IMS_IMSID Allows the user to specify the IMS System ID returned to the AIBTDLI INQY ENVIRON call.
ES_IMS_INQY_OTMA Returns TPIPE, MBR, SYNC, and MSYNC to an INQY call.
ES_IMS_INQY_UNKNOWN Value returned to an INQY call.
ES_IMS_IRLM Enables Internal Lock Resource Manager (IRLM) locking. IRLM locking more closely parallels mainframe IMS database DB locking behavior, reducing data constraint and potential for deadlock.
ES_IMS_LOCALDLI Deprecated. See IMS Database Locking. When set to 1, directs batch program execution to process all IMS DB calls entirely in the JES initiator providing significant performance improvement. All IMS DB control processes accessed from the batch program must be stopped before execution because they become exclusively owned by JES until the program completes.
ES_IMS_LOCK_TIMEOUT The number of seconds during which IMS DB control continues to retry a locked record before timing out. Valid values are 0 to 65535. The default is 30 seconds; a value of 0 indicates an indefinite wait time.
ES_IMS_LTERM_PREFIX
Note: This is a technology preview feature only. It is being made available to allow you to test and provide feedback on this new capability; however, this feature is not intended for production use and it is not supported as such.

Enables specification of a one- to four-character alternative LTERM prefix to apply when ES_IMS_SINGLE is set to N. The default is OTMA.

ES_IMS_LU_LTERM Determines the value of the LTERM literal returned by the MFS system. Valid values are: Y to return the LU name; N to return the user ID.
ES_IMS_MESGQ Sets the configuration for the IMS TM message queue. See ES_IMS_MESGQ in Environment variables in alphabetical order for details.
ES_IMS_PATH The location of compiled COBOL applications.
ES_IMS_PLI_INDIRECT_PCBADDR

Determines whether the PL/I program converts the PCB address list from a direct to an indirect addressing technique. Set the variable to one of the following values:

D
If the main program is a PL/I program, PCB addresses are converted from a direct to an indirect addressing technique.
Y
Always converts addresses from a direct to an indirect addressing technique as long as the PSB language is set to PL/I.
N
Never converts addresses from a direct to an indirect addressing technique.

The default is D (dynamic).

ES_IMS_RCLASS

Creates a set of newly-named IMS security resource classes, appending the variable's value (maximum of seven characters) to each resource class' default character.

Create theses custom-named classes if you are using the same ESM active directory with two Enterprise Server systems and your security needs to differ for each.

See Resource Classes for IMS Security for the names of the resource classes created if this variable is not set.

ES_IMS_RELEASE Allows the user to specify the IMS Release returned to the AIBTDLI INQY ENVIRON call.
ES_IMS_REGION Allows the user to specify the IMS Region returned to the AIBTDLI INQY ENVIRON call.
ES_IMS_ROLLBACK Enables automatic Backward Recovery; enabled by default.
ES_IMS_ROLLFORWARD Enables or disables Forward Recovery logging. Valid values are: Y to enable; N to disable. The default is N.
ES_IMS_SINGLE
Note: This is a technology preview feature only. It is being made available to allow you to test and provide feedback on this new capability; however, this feature is not intended for production use and it is not supported as such.
Enables or disables support for the same user ID to be signed on to multiple LUs simultaneously. Valid values are: Y to disable; N to enable. The default is Y.
ES_IMS_SPARSE_EXIT_LANG
Indicates the language of the IMS DB secondary index sparse routines. Set the variable to one of the following values:
  • C (for COBOL)
  • A (for Assembler)
By default, this variable is not set (sparse exits are disabled).
ES_IMS_SUPPORT Enables IMS support.
ES_IMS_TLOG_COMPRESS When set to 0 (zero), disables compression of the Backward Recovery TLOG file. When not compressed, the file contains only the information required to recover databases. The default is enabled.
ES_IMS_TLOG_FLUSH When set to 1, forces the frequent flushing of TLOG and database buffers to disk.
Note: This environment variable is deprecated. Use ES_IMS_DB_TLOG_WRITETHRU to flush TLOG buffers and ES_IMS_DB_COMMIT_FLUSH to flush database buffers.
ES_IMS_TLOG_MAXSIZE Maximum size of the IMS DB transaction logging file in bytes. The default is 4GB or h"FFF00000".
ES_IMS_TLOG_PATH The location of IMS DB transaction logging files. The default is the Enterprise Server system directory.
ES_IMS_TLOG_THRESHOLD Threshold size of the IMS DB transaction logging file. When reached, the current TLOG file is closed and a new TLOG file created for subsequent transactions. The default is 2GB or h"7FFFFFFF".
ES_IMS_LOCK_RETRY_DELAY The IMS DB lock retry delay in milliseconds.
ES_IMSCFG The location of the IMS configuration files IMSCONFG.DAT. This is reserved for future use.
ES_IMSDAT The location of IMS DB data files.
ES_IMSLIB The location of DBDGEN2.DAT, DBDGEN2F.DAT and PSBGEN3.DAT files.
ES_MFSLIB The location of the control blocks generated by the MFS generation program.
ES_MOD3650 The default MOD file to be displayed after a successful sign-on to IMS. See ES_DFS3650.
ES_SSTM_IMS Location of the JCL used to initialize the SSTM IMS environment.
ES_TRX3650 The default transaction to run after a successful sign-on to IMS. See ES_DFS3650.
ES_TMC_AGGREGATE Controls the performance environment for IMS TM data stores. See ES_TMC_AGGREGATE in Environment variables in alphabetical order for details.
ES_USR_DFLT_IMS Allows you to override the default user when no user is logged on for IMS authentication.
ICONN1 Controls the client TCP connection status of an IMS Connect emulator.
IMSCPY The location of copybook files for DBDGEN, PSBGEN and MFSGEN utilities .
MFIMS_ACBDUMP_TIMESTAMP Suppresses date/time stamp display in ACB report.
MFIMS_BMPCHKP Returns a QC to a checkpoint call when it the call includes an IO area.
MFIMS_BTS Configures Mainframe Express-format BTS tracing
MFIMS_DIBSTAT_CODES Specifies additional DIBSTAT return codes to be returned to EXEC DLI program.
MFIMS_DLI_OPT Specifies DL/I call optimization flags.
MFIMS_DIAG Enables IMS BTS format diagnostic tracing.
MFIMS_FLUSHTRACE Flushes BTS trace file to disk after every write.
MFIMS_FP_DA Bypasses keycheck on IMS Fastpath DB delete.
MFIMS_LOADMVS Disables load of MVS support for IMS application programs.
MFIMS_PCBCALL Allows a standalone EXEC DLI program to issue a PCB call.