OLDS support for zHyperWrite

In IMS 15.3, users can choose whether or not the IMS Logger uses zHyperWrite to write data to the online log data sets (OLDS).

Using zHyperWrite for the OLDS decreases replication latency and makes writes to the OLDS complete quicker in a synchronous replication environment.

Note: This optional enhancement requires that DFSMS APAR OA51385 be applied to your environment and the OLDS be defined as extended format data sets.

Log record changes

No changes to log records. However, as part of the IMS 15 base, the value of the OLDS sub-parameter of the ZHYPERWRITE parameter is included in the x’4507’ record as flag ST4507_F2_ZHYPOLDS.

Changes to installing and defining IMS

zHyperWrite can be used for writing to the OLDS to decrease replication latency. To enable or disable zHyperWrite for the OLDS, you have the following options:
  • Use the OLDS= keyword in the ZHYPERWRITE= parameter in the LOGGER section of the DFSDFxxx PROCLIB member. For more information, see LOGGER section of the DFSDFxxx member.
  • With APAR PH02149 (PTF UI61325) installed, you can use the OLDS(Y) parameter in the UPDATE IMS SET(LCLPARM(ZHYPERWRITE()) command to dynamically enable zHyperWrite without restarting the IMS system. For more information, see UPDATE IMS command.
You must ensure that all the OLDS that will be used by the IMS system are defined as extended format data sets.

To disable this enhancement, remove the OLDS=YES parameter or change it to OLDS=NO.

Changes to commands

The command output of /DISPLAY OLDS shows whether zHyperWrite is used when data is written to the OLDS. If zHyperWrite is enabled, OLDS=YES is displayed. If zHyperWrite is not enabled, OLDS=NO is displayed.

Documentation changes

The following table lists the publications that contain new or changed topics for the zHyperWrite for the OLDS enhancement. Publications that are not impacted by this enhancement are not included in the table.

Table 1. Links to topics that have new or changed content for this enhancement
Publication Links to topics
Release planning
System definition
System administration
IMS commands IMS commands