Clear pending and clear error processing - assure_mimix

Clear pending and clear error processing - assure_mimix - 10.0

Assure MIMIX Operations Guide

Product type

Software

Portfolio

Integrate

Product family

Assure

Product

Assure MIMIX™ Software

Version

10.0

Language

English

Product name

Assure MIMIX

Title

Assure MIMIX Operations Guide

2023

First publish date

1999

Last updated

2024-03-12

Published on

2024-03-12T11:06:36.794496

The Clear pending and Clear error prompts on the STRDG command provide flexibility when starting a data group by allowing you to optionally reset error status conditions on data group file entries and discard pending journal entries that are stored in the journal log space. Clear pending resets the starting point for all data group file entries and object entries. Clear error clears the hold log spaces.

When clearing pending entries, you can optionally specify which system to use for determining database file network relationships when distributing files among database apply sessions. The System for DB file relations (DBRSYS) prompt identifies which system is used to assign data group file entries to apply sessions when the start request specifies to clear pending entries in all apply sessions.

The following table shows the processing that occurs based on the selection made for the Clear pending (CLRPND) and Clear error (CLRERR) prompts. The Clear pending and Clear error prompts work independently. For example, when CLRPND(*NO) is selected, no clear pending processing occurs.

Table 1. CLRPND and CLRERR processing
CLRPND	CLRERR	Processing Description	Notes
*NO	NO or CLRPND	Data groups start with regular processing: Data group file entry status remains unchanged. Hold logs remain unchanged.	When CLRPND is NO, the value CLRPND is the same as *NO for CLRERR.
*NO	*YES	Data group file entries in HLDERR, HLDRGZ, HLDRNM, HLDPRM, and HLDRLTD status are cleared. Tracking entries in HLDERR status are cleared. Hold log space is deleted. Data group object activity entries in any failed status are changed to CC (Completed by clear request).	See File entry states See Log spaces
*YES	*NO	Note: CLRPND(YES) will not start a data group when there are open commit cycles on files defined to the data group. Data group file entries in HLDRGZ, HLDRNM, and HLDPRM status are cleared and reset to active. Data group tracking entries in HLDRNM are cleared and reset to active. Data group file entries and tracking entries in HLDERR status remain unchanged. Data group object activity entries in any active status are changed to CC (Completed by clear request). If there is a requested status at the time of starting, it is cleared. Journal, hold, tracking entry hold, and apply history log spaces are deleted. The apply session to which data group file entries are assigned may change. This is possible when starting a data group configured for single-threaded database apply processes (NBRDBAPY has a numeric value) and when starting a data group following a conversion to or from multithreaded database apply processing.	See File entry apply session assignment See Single apply session processing See Log spaces
*YES	YES or CLRPND	Note: CLRPND(YES) will not start a data group when there are open commit cycles on files defined to the data group. Data group file entries in HLDERR, HLDRGZ, HLDRNM, HLDPRM, and HLDRLTD status are cleared and reset to active. Data group file entries in HLDRTY status remain unchanged. Data group object activity entries in any failed or active status are changed to CC (Completed by clear request). Tracking entries in HLDERR and *HLDRNM status are cleared and reset to active. Tracking entries are primed if any configuration changes occurred for data group object entries or data group IFS entries. If there is a requested status at the time of starting, it is cleared. Journal, hold, and apply history log spaces are deleted. The apply session to which data group file entries are assigned may change. This is possible when starting a data group configured for single-threaded database apply processes (NBRDBAPY has a numeric value) and when starting a data group following a conversion to or from multithreaded database apply processing.	See File entry states See File entry apply session assignment See Single apply session processing See Log spaces When CLRPND is YES, the value CLRPND is the same as *YES for CLRERR.
File entry states: Files in specific states will not reset to active when you specify YES on the Clear Error prompt. If you have set data group file entries to any of these states, the following process exception applies: Note: The only states that can be set using the Set Data Group File Entry (SETDGFE) command are HLD, RLSWAIT, ACTIVE, and HLDIGN. All other states are the result of internal processing. HLD - Journal entries cached before YES is specified are discarded. If ALL or ALLSRC is specified on the Start processes prompt, all subsequent entries from the specified starting point will be cached again. RLSWAIT - Journal entries are discarded as they wait for the synchronization point to arrive in the journal stream. This occurs regardless of the value specified for Clear Error or Clear Pending. HLDIGN - Journal entries are discarded until the file status is changed to something else. HLDSYNC - Journal entries are ignored since an external process is actively synchronizing the file. When that event completes normally, the file is set to *RLSWAIT.
File entry apply session assignment: For configured files that have temporal table relationships (base to history files), MIMIX assigns the files to the same apply session. Files may be reassigned to different apply sessions when a conversion to or from multithreaded database apply processing is performed by the Convert RG for Multithreading (CVTRG) command. In environments that are not configured for multithreaded database apply processing, clear pending processing attempts to load-balance the data group file entries among the defined apply sessions when the data group being started is configured for single-threaded database apply processing and when starting a data group following a conversion from multithreaded to single-threaded processing. If the requested apply session in the data group file entry definition is ANY, or if it is DGDFT and the requested apply session for the data group definition is ANY, then the apply session to which the data group file entry is assigned may be changed when processing occurs. For data groups configured to replicate through the user journal and which replicate temporal tables or use basic support for constraints, the requested apply session may be ignored to ensure that related files are handled by the same apply session. For data groups configured to allow target constraint management, configured files with foreign key constraints may be automatically assigned to different apply sessions. The value specified for System for DB file relations* (DBRSYS) determines the system used to determine database file relationships while assigning files to apply sessions. This parameter is evaluated only when the start request specifies to clear pending entries for all database apply sessions. The default value, *TGT, uses the target system to determine the file relationships.
Single apply session processing: In most situations, you will perform clear pending processing on all apply sessions belonging to a data group by specifying ALL or DBALL on the Start processes (PRC) prompt. MIMIX also supports the ability to perform clear pending processing on a single apply session, which is useful for recovery purposes in certain error situations. The System for DB file relations (DBRSYS) parameter is ignored when the start request specifies a specific apply session. To perform clear pending processing on a single apply session, specify PRC(*DBAPY) and the specific apply session (APYSSN).
Log spaces: Because they have not been applied, journal entries that exist in the journal log space are considered pending. Journal entries that exist in the hold log space, however, are considered in error. The Clear pending and Clear error prompts affect which log spaces are deleted (and recreated) when a data group is started.