Changing target side locking for DBAPY processes - assure_mimix - 10.0

Assure MIMIX Administrator Reference

Product type
Software
Portfolio
Integrate
Product family
Assure
Product
Assure MIMIX™ Software
Version
10.0
Language
English
Product name
Assure MIMIX
Title
Assure MIMIX Administrator Reference
Copyright
2023
First publish date
1999
ft:lastEdition
2024-06-11
ft:lastPublication
2024-06-11T18:33:16.692940

A MIMIX configuration option, Lock member during apply, determines the type of lock that the database apply (DBAPY) processes obtain on file members being processed on the target node. The type of lock obtained by MIMIX affects the type of lock that can be obtained by other applications on the target node.

Database apply processing will also lock objects as needed to replicate changes from the source node.

The shipped default value for Lock member during apply and the ability to change its value is dependent on whether single-threaded or multithreaded database apply processing is configured.

Lock member during apply is an element of the File and tracking entry options (FEOPT) parameter and can be specified in a data group or in data group object entries.

For data groups that use single-threaded database apply processing, the Lock member during apply element supports several values. The data group’s value of *DFT resolves to *EXCLRD. The database apply process holds an exclusive, allow read lock on file members being processed on the target node, which allows other users read-only access to the data.

Note: In a data group that uses multithreaded database apply processing and its associated data group object and file entries, you cannot change the type of lock obtained by MIMIX. Multithreading requires that the apply process does not hold a lock on members on the target node. The data group’s value of *DFT resolves to *NONE and cannot be changed. In data group entries for a data group that uses multithreading, the only valid value for Lock member during apply is *DGDFT.

In the configurations that allow locking, you can change the value of Lock member during apply in a data group that is part of a resource group that does not use multithreading, in a data group that is not part of an application group, or in their associated object entries. If such a data group is configured to use database-only replication processes, you can change the value in its associated file entries.

In configurations that allow locking, members are locked only when the apply process is started and affects members whose file activity status is active.

In configurations that allow locking, you can configure MIMIX to use a shared, no update (*SHRNUP) lock or to use no lock at all. This may be useful when only read or query access is needed to replicated files on the target node or for an instance that was migrated from another product which obtained different locks for replication activity. However, changing the type of lock used may cause contention for access to the data being replicated, which may affect performance of the apply process.

Changing target side locking for a data group

To change target side locking for a data group, do the following from a management system:

  1. From the Work with Data Group Definitions display, use option 2 (Change) to access the data group definition you want.

  2. On the resulting display, press F10 (Additional parameters), then press Page Down to locate the Number of DB apply sessions prompt. If the value is numeric, you can continue with these instructions because the data group does not use multithreading.

  3. Press Page Down multiple times to locate the Lock member during apply prompt. (It is an element of the File and tracking ent. opts (FEOPT) parameter.)

  4. Specify the value you want for the Lock member during apply prompt,

  5. Press Enter.

The change is not effective until replication processes for the data group are ended and started again.

Changing target side locking for a data group object entry or file entry

To change target side locking for a data group entry, do the following from a management system:

  1. Confirm that the data group does not use multithreading. Do the following:

    1. From the Work with Data Group Definitions display, use option 2 (Change) to access the data group definition you want.

    2. On the resulting display, press F10 (Additional parameters), then press Page Down to locate the Number of DB apply sessions prompt. If the value is numeric, the data group does not use multithreading and you can continue with these instructions.

    3. Press F12 (Cancel).

  2. From the Work with Data Group Definitions display, do one of the following to access configured entries in the data group you want:

    • Use option 20 (Object entries) to access configured data group object entries for library-based objects.

    • Use option 17 (File entries) to access configured data group file entries. Use this only for data groups configured to use database-only replication processes.

  3. On the resulting display, press F10 (Additional parameters), then press Page Down multiple times to locate the Lock member during apply prompt, (It is an element of the File and tracking ent. opts (FEOPT) parameter.

  4. Specify the value you want for the Lock member during apply prompt,

  5. Press Enter.

The change is not effective until replication processes for the data group are ended and started again.