Performance and Tuning › Delta Level Management

Delta Level Management

CA Endevor SCM provides three methods to consolidate delta levels: Automated Element Level Versioning; Auto Consolidation; and Aged Delta Retention. Automated Element Level Versioning is the default, but it is also used in conjunction with the other two methods, both of which are optional. Aged Delta Retention is managed at the system level; the others are managed at the type level. These methods are summarized in the following table:

Automated Element Level Versioning

Automated Element Level Versioning increases the limit on delta levels to 9996 and is activated at the Type level.

For each Type to be activated, navigate to the Type Definition panel in foreground and set AUTO CONSOL to N and LVLS TO CONSOL to 0. If you were not previously using Auto Consolidation, and had not changed these fields, then these values will already be set.

Alternatively, you can run the Batch Admin DEFINE TYPE action to set these field values for each Type to be activated. With Auto Consolidation turned off, you may eventually run out of levels or accumulate more levels than you really need.

Element Delta Consolidation Method

Auto consolidation is implemented by type and lets you specify the physical level threshold at which the consolidation process is initiated and the number of physical levels to consolidate when the threshold is met. The maximum number of levels you can keep is 96.

Element data consolidation consists of the following two functions:

• Consolidation level (CONSOL AT LVL)-specifies when the consolidation process is initiated. This is the maximum number of physical levels you want stored on the system. For example, the CONSOL AT LVL parameter is set to 96. When the physical number of levels reaches 97, CA Endevor SCM begins the consolidation process.

  Note: For the most efficient level consolidation across environments, set this parameter to the maximum value of 96.

• Number of levels to consolidate (LVLS TO CONSOL)-specifies the number of physical levels to consolidate when the threshold is met. For example, suppose the LVLS TO CONSOL parameter is set to 25, and the CONSOL AT LVL (consolidation trigger) is set to 96. An element in Production is at the maximum level 0196, and vvll 0197 is about to be moved in. Prior to saving the 97^th level, CA Endevor SCM does the following:
  • Merges levels 01 through 25 together to create a single delta level (level 01)
  • Renumbers the remaining levels to 02 through 72:

    CONSOL AT LVL + 1 97

    —LVLS TO CONSOL: — 25

    Minimum level 72

  When working in the lower stages where the level number is not equal to the physical number of levels, Auto Level Versioning is used to increment or “roll over” the vvll value until the number of physical levels specified on CONSOL AT LVL is reached.

  Using the same consolidation values as in the prior example, suppose an element at vvll 0194 is retrieved from the production stage for modification. When it is added back into CA Endevor SCM at a lower stage, level 0194 is fetched back for compare and level 0195 is created. The level number is 95, but the number of physical levels is two-- 0194 and 0195. For auto consolidation to be triggered in this lower stage, 94 more changes would have to be made to get up to 96 physical levels. Auto versioning comes into play when vvll 0199 is reached, the next change would roll over to 0200, then 0201 and so on until 0290 is reached (0194+96=0290), should one more change be attempted auto consolidation would be triggered causing the lower 25 levels, 0195 through 0220, to become a new 0195, and levels 0221 through 0290 to be renumbered accordingly.

  Determine the maximum and minimum number of levels you want to store on the system. Using these values, you can calculate the number of levels to consolidate (LVLS TO CONSOL). The maximum value is specified in the consolidate level (CONSOL AT LVL) field. The minimum value is only used for calculation purposes. The difference between the maximum value and the minimum value is the number of levels to consolidate (LVLS TO CONSOL).

  Maximum level (CONSOL AT LVL)

  —Minimum level

  Levels to consolidate (LVLS TO CONSOL)

  The larger the number of levels you retain, the longer it takes CA Endevor SCM to rebuild, because each delta level requires additional I/O operations.

  Note: Verify the parameter values match for the same element type across different CA Endevor SCM locations.

For more information about the type definition fields LVLS TO CONSOL and CONSOL AT LEVEL, see Type Definition Fields in the chapter Defining Inventory Structures.

Aged Delta Retention Method

The Aged Delta Retention method lets you set the number of months that delta levels are retained. The maximum retention limit is 999 months. This option is inactive by default and is set on each system definition in foreground or batch. It can be set for elements, components, or both, and overrides any consolidation levels set on all type definitions in that system. This method is invoked only at the end of the mapped system location route.

When auto age level retention is set, change levels for all types in the system expire after the number of months specified on the system definition. The base element or component is rebuilt to reflect the changes from the deleted levels, with the base delta version and level numbers set to the last discarded version and level. The delta format you are using, reverse, forward, or full image, determines how the consolidated level is built. For reverse and full image deltas, change levels that expire are dropped. For forward deltas, change levels that expire are incorporated into the base.

Example: Aged Delta Retention

In this example, the delta levels are set to expire after five months, and the element is changed and moved through the lifecycle as follows:

• The element named ELEMENT1 is added to stage 1 of the Test environment from stage 2 of the Production environment. The highest level of the element in stage 2 of the Production environment, which is 0103, is fetched to stage 1 of the Test environment.
• The element is updated in stage 1, Test, four times over a ten month period. Each time the element is saved, a new level is created with the level number incremented by 01. So that after the element is saved four times, the new levels are 0104, 0105, 0106, and 0107.
• The element is moved with history to stage 2, Test. All the levels in stage 1, Test (0103, 0104, 0105, 0106, and 0107) are included in the move.
• The element is moved with history to stage 2 of the Production environment. Auto age level retention is triggered because the element has reached the end of the map and some of the element levels are older than the five month retention period. The result of the move with history to stage 2, Production, depends on the delta format as described next:

  If reverse delta (the base is a full copy of the current code):

  • Levels 1 thru 4 are removed, because they are older than 5 months.
  • Level 4 becomes the new base level 00.
  • A new base delta record is created reflecting level 4 with the following modifications:
    • All level 4 change statements are removed.
    • Insert and delete record counts are set to zero.

  If forward delta (the base is a full copy of the original code):

  • Base is re-built to contain change levels 1 thru 4, because they are older than 5 months.
  • Level 4 becomes the new base level 00.
  • A new base delta record is created. The base level 0 record reflects level 4 with the following modifications:
    • All level 4 change statements are removed.
    • Insert and delete record counts are set to zero.

  If full image delta

  • Levels 1 thru 4 are removed, because they are older than 5 months. The full image deltas for level 0 through level 3 are deleted.
  • A new base level record is created. The base level 0 record reflects level 4.

Note: Regardless of the delta level format, the delta's main control record (the first record in the file) is updated to reflect the new base level. In this example, level 4 is made into the new base level 0. The base record count, date and time fields reflect level 4.The last level value and record count reflect level 4. The last level date and time fields are set to blanks.

The following chart illustrates this example and shows how delta levels are incremented and consolidated using the auto age delta retention feature.

Note: In this example, at the end of the map, if the level format is:

• reverse delta, then levels 1 thru 4 are removed. Level 4 becomes the new base level 00.
• forward delta, then the base is re-built to contain change levels 1 thru 4. Level 4 becomes the new base level 00.
• full image delta, then levels 1 thru 4 are removed.

Implement Age Level Retention

To retain delta levels for a specific number of months, you can activate the Age Level Retention feature for each system in your environment. This may help you to meet record keeping requirements for your organization or regulatory requirements. To activate this delta level management method in foreground, you can update the system definition through the online environment update facility. You can activate Age Level Retention for elements, components, or both.

Note: By default, the age delta level retention options on all the system definitions are turned off for both elements and components. The default settings are ELEMENT=N and COMPONENT=N and the only allowable value for their corresponding RETAIN LVLS FOR fields is 0.

To implement Age Level Retention

1. On the System Request panel, select option U.

   The Update System Definition panel opens. The following options appear in on this panel in the AUTO AGE LEVEL RETENTION OPTIONS fields.

2. (Optional) Set the ELEMENT option =Y.

   This activates Age Level Retention for elements of all types in the system.

3. To specify how many months the element delta levels will be retained, type the number of months in the RETAIN LVLS FOR field that appears next to the ELEMENT option. Allowable values are 1 to 999 and the default is 999.

   Element delta levels will be retained for the number of months specified, provided the ELEMENT option is set to Y.

4. (Optional) Select Y for the COMPONENT option.

   This activates Age Level Retention for components of all types in the system.

5. To specify how many months the element delta levels will be retained, type the number of months in the RETAIN LVLS FOR field that appears next to the COMPONENT option. Allowable values are 1 to 999 and the default is 999.

   Component delta levels will be retained for the number of months specified, provided the COMPONENT option is set to Y.

Note: After you set retention limits in the system definitions, you can examine what effect this will have on elements and components by using the Age-Managed Delta utility, in examine mode, to see which delta levels have expired. For more information, see the chapter "Using the Age-Managed Delta Utility" in the Utilities Guide.