Zero Downtime Option for SAP S/4HANA

Impact Analysis Usage

This section deals with aspects of the impact analysis usage.

If you keep the default selection for all fields, the statistics file ZDIMPANA.ZIP located in <SUM directory>/abap/save is used.

Starting the Impact Analysis

There are two possibilities to run the impact analysis:

  1. In batch mode: The Impact Analysis is called during a SUM run in phase RUN_IMPACT_ANALYSIS_ZDO. This phase uses the file ZDIMPANA.ZIP.

  2. As a dialog from the SUM toolbox: The impact analysis of the delivered as part of the Software Update Manager Toolbox. For more information, see SAP Note 3092738 Information published on SAP site. After the phase RUN_RSPTBFIL_ZDM_CLASSIFY is completed, it can be called in dialog mode.

Evaluating the Impact Analysis

If something is found, SUM stops in phase RUN_IMPACT_ANALYSIS_ZDO with an error message:

Log file for phase RUN_IMPACT_ANALYSIS_ZDO: <DIR_PUT>/SUM/abap/log/IMPANAUPG.<SID>

The results need to be checked in detail, which takes a while. Therefore, you can ignore the error at this time by selecting Ignore phase errors and proceed to next phase. While SUM continues with the update, check every single result of the impact analysis carefully.

You have two options to perform the check:

  • Read the text-based log file output.

  • Use the dialog mode of the impact analysis in SUM Toolbox.

Impact Analysis Output in SUM Toolbox

In the following, you see an example of an impact analysis output triggered in the dialog mode:

The user interface is divided into five sections:

Section

Purpose

(1) File Selection

Displays the relevant data for performing the impact analysis.

The following three scenarios are covered:
  1. Impact analysis on the system where a ZDO upgrade procedure is active.

    • The source for the table classification data is the database table in the system that contains this information.

    • The source for the table statistics is the file ZDIMPANA.ZIP located in <SUM directory>/abap/save.

  2. Impact analysis on the system where a ZDO upgrade procedure is active, but using a new table statistics file.

    • The source for the table classification data is the database table in the system that contains this information.

    • The table statistics are uploaded via SAP GUI.

  3. Removed impact analysis on any other system of the same system landscape as, such as development system.

    • The table classification data has been exported via SUM toolbox from a system where the ZDO upgrade procedure is completed. The output file PUTTB_SHD.ZIP is uploaded via SAP GUI.

    • The table statistics are uploaded via SAP GUI.

(2) Header

Displays information such as export date, source system ID, number of evaluated days, and whether software changes such as importing shipments are included during the exported time.

(3) Overall Summary

Displays the total number of cloned tables, read-only tables, and additional database space for cloned tables. It also displays the total change volume for all tables in the system, and the online replication volume for cloned tables per day. These numbers help you to better understand the ratio of cloned tables compared to the total number of changes in the system.

(4) Impact Analysis Findings

Summarizes and aggregates the issues. Also, gives an estimate on the required database free space for the clone tables.

(5) Result table in ALV grid

Displays results at severity, category, and table level.
Possible Categories

Category

Comment

Read-only

The most critical category that always has to be checked in detail.

The table is used in the productive system according to the provided statistics, but is read-only during the runtime of the bridge subsystem.

Triggers

If database triggers exist in the production system, a reload can be necessary, or the trigger must be dropped. For more information, see SLT Replication Handling.

Cloned

Large tables that are cloned.

Smart-switch

Tables that are cloned, but changed frequently in production.

All clone tables are renamed in phase EU_SWITCH_ZDM, which requires an exclusive lock. However, the more changes a table has, the more difficult it is to get an exclusive table lock.

Comp. view

Tables that receive a new non-key field can be kept as "shared". The bridge subsystem only sees the old fields using a compensation view.

The new field is added dDuring the upgrade in phase PARCONV_UPG. This requires an exclusive table lock.
Possible Severities:

Severity

Comment

Green (square)

Uncritical finding. Usually, no further action is required.

By default, these entries are hidden. To display them as well, click the green button in the ALV Grid menu bar.

Orange (triangle)

 No immediate action is required. You are only reminded of a specific message, such as a warning that a table is smart-switched.

Red (circle)

These messages must be checked in more detail with the business teams, as there is a potential risk to productive business operations.