Are you up for running a nZDM maintenance activity soon? The Software Update Manager (SUM) comes with a feature named near-Zero Downtime Maintenance (nZDM) technology.
You can activate this feature in the Advanced preconfiguration mode in SUM. The nZDM feature helps to minimize the Business Downtime while performing the following maintenance activities:
- Support package installation
- Enhancement package installation
- Update of ABAP-based SAP Business Suite or SAP NetWeaver systems
Since downtime-relevant update phases are executed while the system is still up and available for business users, nZDM significantly reduces the Business Downtime. Those downtime relevant update phases are:
- Table structure adjustment including conversions, based on Record & Replay technique
- Main import, based on Record & Replay technique
With the Record & Replay technique in nZDM, which uses the Change Recording and Replication (CRR) framework, you can capture database changes in tables on the production instance during uptime. This trigger-based change recording technique allows importing new content into the shadow instance and adjusting table structures to the new release while all users are still able to work in the production system. The recording of data changes is started automatically by the SUM and is transferred to the shadow instance iteratively after the table structure adjustment.
You can monitor the progress of data transfer by logging into the shadow instance, once prompted by SUM, and call transaction CRR_CONTROL. In addition you can stop and restart the data transfer. Furthermore, you can add and exclude tables from the data transfer.
For huge tables, being included in the process, we saw initially runtimes of several days and weeks for SUM phases RUN_FDCS_SEGMENT and RUN_FDCT_TRANSFER. With some enhancements to our dbsl, we could drastically reduce the runtime. To benefit from this enhancement, you must use at least SUM 2.0 SP 02. Furthermore, you must include a SAP kernel package which includes a dbsl with minimum patch level:
- SAP Kernel 7.42 is not supported.
- For SAP Kernel 7.45 the required patch level is 725.
- For SAP Kernel 7.49 the required patch level is 513.
- A patch for SAP Kernel 7.53 is currently in process.