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Updates to IMS DEDB Fast Recovery V2.2 User's Guide and Reference

Product Documentation


Abstract

Updates that apply to IMS DEDB Fast Recovery V2.2 User's Guide and Reference (SC27-0928-05).

Content

The most recent updates appear at the top of the list.


Update 3

Date of change: March 2019

Change description: Documentation changes by APAR PH08688. This APAR enables IMS DEDB Fast Recovery to use the DFSMDA macro TYPE=CATDSHLQ statement for allocating the IMS directory bootstrap data set dynamically.

Topics: Changes apply to multiple topics.

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Topic:  IMS DEDB Fast Recovery overview >   Processing environment limitations

This topic, which has been updated by Techdoc Update 2, has been modified as follows:

 

IMS DEDB Fast Recovery has certain limitations for its processing environment.

IMS DEDB Fast Recovery cannot be used in an IMS RSR environment in the following cases:

  • A remote site tracker failure
  • A remote site takeover failure

To use dynamic allocation parameter lists that are registered by the DFSMDA macro of IMS V5 or earlier, you must rebuild the lists by using the DFSMDA macro of the latest IMS version.  


To use IMS managed ACBs,  you must register the IMS catalog database to the DBRC RECON data sets.
IMS DEDB Fast Recovery does not support the TYPE=CATDSHLQ statement defined in the DFSMDA member. Also, if both of the following conditions are met, IMS DEDB Fast Recovery cannot use IMS managed ACBs:
  • IMS catalog database is not registered to the DBRC RECON data sets.
  • SYSDSNHLQ parameter is not specified in the IMS Catalog Definition exit routine (DFS3CDX0) or the DFSDF xxx member of the IMS.PROCLIB data set.

==========

Topic: JCL and control statements > JCL requirements

DD statement has been updated as follows:

 

DD statements

STEPLIB DD

Specifies the library containing the IMS DEDB Fast Recovery load modules. Because IMS DEDB Fast Recovery runs as an MVS authorized program, this library must be registered as an APF authorized library. For an explanation of how to register, see the MVS Initialization and Tuning Reference for the version and release of MVS you are using. The IMS.SDFSRESL (the library containing IMS load modules) of the IMS to be recovered must also be specified in the STEPLIB statement. IMS DEDB Fast Recovery uses the IMS module (DFSVC000) in the data set: 

  • By checking the version and release in the module, IMS DEDB Fast Recovery verifies and determines the version and release of the IMS being used.
  • To display messages to the system console of the IMS to be recovered, IMS DEDB Fast Recovery uses the routing code and the descriptor code of the system console contained in the module.

IMS DEDB Fast Recovery also uses IMS DBRC modules. A user-written logger exit routine (DFSFLGX0) is invoked during the execution of IMS DEDB Fast Recovery if the exit routine is present. DFSFLGX0 is called once with an initialization call, once with a write call for each log buffer of data that is written, and once with a termination call.
If you want to use automatic RECON loss notification, specify the data set that contains the dynamic allocation parameter lists for the DBRC RECON data sets in the IMSDALIB concatenation or the STEPLIB concatenation.
To use IMS managed ACBs in an IMS managed ACB environment, specify the data set that contains the IMS Catalog Definition exit routine (DFS3CDX0) to the STEPLIB concatenation.
To allocate the IMS directory data sets dynamically, specify the data set that contains the DFSMDA member with TYPE=CATDSHLQ statement.



Update 2
Date of change: March 2018
Change description: Documentation change by APAR PI91565. This APAR enhances IMS DEDB Fast Recovery to support ACBs that are managed by IMS (IMS management of ACBs).
Topics: Changes apply to multiple topics.

Topic: IMS DEDB Fast Recovery overview > Processing environment limitations

This topic has been modified as follows:

IMS DEDB Fast Recovery has certain limitations for its processing environment.
IMS DEDB Fast Recovery cannot be used in an IMS RSR environment in the following cases:
  • A remote site tracker failure
  • A remote site takeover failure
To use dynamic allocation parameter lists that are registered by the DFSMDA macro of IMS V5 or earlier, you must rebuild the lists by using the DFSMDA macro of the latest IMS version.

IMS DEDB Fast Recovery does not support the TYPE=CATDSHLQ statement defined in the DFSMDA member. Also, if both of the following conditions are met, IMS DEDB Fast Recovery cannot use IMS managed ACBs:
  • IMS catalog database is not registered to the DBRC RECON data sets.
  • SYSDSNHLQ parameter is not specified in the IMS Catalog Definition exit routine (DFS3CDX0) or the DFSDFxxx member of the IMS.PROCLIB data set.

IMS DEDB Fast Recovery does not support the following functions of IMS:
  • DEDB alter function
  • IMS management of ACBs
  • Dynamic database definition enhancements
Topic: JCL and control statements > JCL requirements

EXEC statement has been updated as follows:

EXEC statement
The EXEC statement must be in the following form:




ACBLIB=
Specifies whether to enable the automatic determination function. When this function is enabled, IMS DEDB Fast Recovery searches for active application control blocks (ACBs) and uses the detected active ACBs.
This parameter can be used with IMS Version 14 or later.
  • ACBLIB=C
      • IMS DEDB Fast Recovery detects active application control blocks automatically.
        If IMS management of ACBs is enabled, IMS DEDB Fast Recovery uses the active ACBs in the IMS directory.
        If active ACBs are managed in ACBLIB data sets, IMS DEDB Fast Recovery uses the active ACBs found in the ACB library that the IMSACBA DD or IMSACBB DD statement specifies.
    ACBLIB=F
      • IMS DEDB Fast Recovery uses the active ACBs found in the ACB library that the IMSACBA DD statement specifies.
        Use ACBLIB=F only when IMS management of ACBs is enabled and IMS directory data sets cannot be used.
    The default is ACBLIB=C.
Topic: JCL and control statements > JCL requirements

DD statement has been updated as follows:

DD statements
STEPLIB DD
Specifies the library containing the IMS DEDB Fast Recovery load modules. Because IMS DEDB Fast Recovery runs as an MVS authorized program, this library must be registered as an APF authorized library. For an explanation of how to register, see the MVS Initialization and Tuning Reference for the version and release of MVS you are using. The IMS.SDFSRESL (the library containing IMS load modules) of the IMS to be recovered must also be specified in the STEPLIB statement. IMS DEDB Fast Recovery uses the IMS module (DFSVC000) in the data set:
    • By checking the version and release in the module, IMS DEDB Fast Recovery verifies and determines the version and release of the IMS being used.
    • To display messages to the system console of the IMS to be recovered, IMS DEDB Fast Recovery uses the routing code and the descriptor code of the system console contained in the module.

IMS DEDB Fast Recovery also uses IMS DBRC modules. A user-written logger exit routine (DFSFLGX0) is invoked during the execution of IMS DEDB Fast Recovery if the exit routine is present. DFSFLGX0 is called once with an initialization call, once with a write call for each log buffer of data that is written, and once with a termination call.
If you want to use automatic RECON loss notification, specify the input data set that contains the dynamic allocation parameter lists for the DBRC RECON data sets in the IMSDALIB concatenation or the STEPLIB concatenation.

To use IMS managed ACBs in an IMS managed ACB environment, add the IMS Catalog Definition exit routine (DFS3CDX0) to the STEPLIB concatenation.

PROCLIB DD
When OLC=G is specified in the EXEC parameter, specify the IMS.PROCLIB data set which includes the DFSCGxxx member, DFSDFyyy member (xxx is the value specified in the CSLG= EXEC parameter, and yyy is the value specified in the DFSDF= EXEC parameter), or both. IMS DEDB Fast Recovery dynamically allocates the OLCSTAT data set by using the name that is specified in the OLCSTAT= parameter in the member. You do not need to specify the OLCSTAT DD statement in the JCL.

If the OLCSTAT= parameter is specified in both DFSCGxxx and DFSDFyyy, one in DFSCGxxx is used.

To use IMS managed ACBs in an IMS managed ACB environment, specify the IMS.PROCLIB data set that includes the DFSDFxxx member (xxx is the value specified for the DFSDF= parameter of the EXEC statement). This member must contain the ACBMGMT=CATALOG parameter in the CATALOGimsid section or the CATALOG section. If both sections are defined in the member, IMS DEDB Fast Recovery uses definitions in the CATALOGimsid section.
IMSACBA DD
IMSACBB DD
Specifies the ACB libraries of the IMS system to be recovered.
IMS DEDB Fast Recovery uses these libraries to initialize DEDB basic control blocks (DMCB and DMAC).

If IMS management of ACBs is enabled, this parameter is ignored.

Note: If some of the databases specified in IMS definition are not actually used in the IMS subsystem, the NOTINIT status for those databases appears in a Database Status list. Even if ACBLIBs specified in the execution JCL are different from the ones used by the failed IMS, IMS DEDB Fast Recovery tries to redo DEDBs (apply the uncommitted update to the CI and write the updated CI to DASD) by using the libraries specified in the JCL when the libraries contain related necessary members. Because IMS DEDB Fast Recovery cannot detect this error, you must be careful in specifying the libraries to be used.
Topic: JCL and control statements > JCL examples

The following new subsection has been added:

Sample JCL for IMS DEDB Fast Recovery for IMS management of ACBs environment (Catalog Definition exit routine)
The following figure is a sample JCL for IMS DEDB Fast Recovery to run in an IMS management of ACBs environment using the Catalog Definition exit routine (DFS3CDX0).

Figure. Sample JCL for IMS DEDB Fast Recovery (IMS management of ACBs environment using DFS3CDX0)




Sample JCL for IMS DEDB Fast Recovery for IMS management of ACBs environment (DFSDFxxx PROCLIB member)
The following figure is a sample JCL for IMS DEDB Fast Recovery to run in an IMS management of ACBs environment using the DFSDF= parameter and the PROCLIB DD statement. The DFSDF= parameter and the PROCLIB DD statements specify the DFSDFxxx member of the IMS.PROCLIB data set.

Figure. Sample JCL for IMS DEDB Fast Recovery (IMS management of ACBs environment using the DFSDFxxx PROCLIB member)

Topic: Troubleshooting > Messages

The following new messages have been added:

DFR3231I IMS MANAGEMENT OF ACBS IS ENABLED. BSDSHLQ=bsdshql

Explanation: IMS DEDB Fast Recovery detected that the IMS management of ACBs is enabled. bsdshql is the high-level qualifier prefix of the IMS boot strap data set.
System action: The job continues.
User response: None. This message is informational.

---

DFR3232E IMS CATALOG API ERROR. FUNCTION=function, RC=rrrrrrrr/ssssssss
Explanation: An error occurred while IMS DEDB Fast Recovery was using the IMS catalog API function.
    • function: The function that failed. The function can be OPEN, LIST, or CLOSE.
    • rrrrrrrr: The return code from the IMS catalog API function.
    • ssssssss: The reason code from the IMS catalog API function.
System action: The job ends with an abend code of U3232.
User response: See IMS System Programming APIs for the return code and the reason code. Correct the cause of the IMS catalog API failure and rerun the job.

---

DFR3233W ERROR READING IMS CATALOG, DMB=dmbname

Explanation: An I/O error occurred while reading the indicated DMB from the IMS catalog.
System action: The processing of the indicated DMB is canceled and IMS DEDB Fast Recovery continues. If the following conditions are met, IMS DEDB Fast Recovery issues message DFR3737W for this DMB:
    • The indicated DMB is a DEDB.
    • IMS DEDB Fast Recovery finds database update log records for areas that are defined in the DEDB.
    • IMS DEDB Fast Recovery cannot validate whether these updates need recovery (REDO).
User response: If the job ended normally, check the Database Status list and the DEDB Area Status list and take necessary actions. If IMS DEDB Fast Recovery issued message DFR3737W, follow the instructions in the User response section of message DFR3737W.

---
The following messages have been updated as follows:

DFR3001E DEDB FAST RECOVERY TERMINATED DUE TO EXEC PARAMETER ERRORS. REASON CODE=nn

Explanation: There is an error in one or more of the EXEC parameters. The type of error is indicated by the reason code nn.
Code
  • Meaning
...
1E
  • A character other than C or F is specified for the ACBLIB= operand.
1F
  • The ACBLIB parameter cannot be used in an IMS XRF complex.

---

DFR3737W RECOVERY SKIPPED FOR DB=dbname AREA=area_name. AREA NOT FOUND IN [ACBLIB | IMS CATALOG]

Explanation: IMS DEDB Fast Recovery finds database dbname updates to area area_name, but it cannot validate if these updates need recovery (REDO).
There is no subsequent X'5926' log record nor the X'5927' log record to show that the area has been deleted by online change.
This condition occurs if the user has changed the IMS block structure since the specified checkpoint was taken.
System action: The job continues, and ends with return code 4 or higher.
User response: Make sure that there is no data integrity problem that is caused by the user by changing the IMS block structure since the specified checkpoint was taken.
If the area has been closed before the IMS failure, there will be no date integrity problem.



Update 1
Date of change: July 2017
Change description: Documentation change by APAR PI83064. A new message.
Topics: Changes apply to multiple topics.

Topic: Troubleshooting > Messages

The following new message has been added:

DFR3253W WADS PROCESSING WARNING. FUNCTION = 04. REASON = nn

Explanation: When Data Facility Storage Management Subsystem (DFSMS) opens a write-ahead data set (WADS), DFSMS issues IEC messages in the job log. This message indicates that the IEC messages in the job log do not require further action.
nn is the reason code in the ACBERFLG field of the ACB. For the details on ACBERFLG, see the DFSMS Macro Instructions for Data Sets for the version and release of MVS you are using.
System action: The job continues.
User response: None.

Publication Number

SC27-0928-05

Copyright Date

2000, 2017

Document information

More support for: IMS Tools

Component: IMS DEDB Fast Recovery

Software version: 2.2.0

Operating system(s): z/OS

Reference #: 7050109

Modified date: 15 March 2019