This documentation supports the 11.2 version of BMC Discovery.

To view an earlier version of the product, select the version from the Product version menu.

Scheduling DDD removal blackout windows

In BMC Discovery systems where discovery (or consolidation) is in progress for most of the available time, contention between the removal (aging out) of DDD nodes (in this case Discovery Access nodes and their children) and the creation of new nodes, might affect the performance of in-progress discovery runs. To avoid this performance impact you can schedule DDD removal blackout windows during which no DDD removal is undertaken.

When should DDD removal blackout windows be used?

DDD removal blackout windows should typically only be used on consolidation appliances when you need to achieve maximum discovery throughput. In virtually every discovery schedule used, the continual aging scheme used by BMC Discovery can remove "old" DDD at a similar rate as they are created.

You can determine whether scheduling DDD removal blackout windows might be beneficial using the DDD removal statistics page. The DDD removal statistics page shows the total number of DiscoveryAccesses in the datastore and those eligible for removal. If DiscoveryAccess removal is keeping up with DiscoveryAccess creation, then the number of eligible Discovery Access nodes is zero, or near zero, DDD removal blackout windows are not required. If the trend of eligible DiscoveryAccess is rising over a two week period, then DDD removal blackout windows might be a solution. See DDD removal statistics page for more information.

Viewing existing DDD aging blackout windows

  1. From the main menu, click the Administration icon 
    The Administration page opens.
  2. In the Model section, click Model Maintenance.
  3. Select the DDD Removal Blackout Windows tab.

When you view the DDD Removal Blackout Windows tab, the active blackout window is highlighted. If multiple blackout windows are active, the one with the longest time remaining before it ends is highlighted. This is not automatically refreshed.

DDD nodes are removed in batches which are not interrupted. Once removal starts, it continues to completion. Therefore, if a batch removal is in progress at the beginning of a DDD removal blackout window, it will continue into the blackout until completion. In normal operation this should take no more than a few minutes.

Adding a new DDD aging blackout window

You can schedule a new DDD aging blackout window to occur daily, weekly, or monthly and can specify a start time and duration.

  1. Click the Add button.
    The Add a New DDD Removal Blackout Window dialog box is displayed.
  2. Enter the information for the blackout window in the fields described in the following table.

    Field Name



    Enter a descriptive comment for the blackout window.


    Select a frequency for the window to operate. For example, this can be Daily, Weekly, or Monthly.
    For a weekly blackout window, you are provided with buttons for each day. Select the day or days that you want the window to operate.
    For a monthly blackout window, you are provided with buttons for each day in the month. Select the day or days that you want the window to operate. Alternatively, select the No Removal On The radio button and choose one of:
    • First
    • Second
    • Third
    • Fourth
    • Last
    and the day that you want the window to operate. In this way you can select the Second Tuesday of the month and so forth.

    Start Time

    Select a time for the window to start.


    Select a duration in hours. This is the length of time that the blackout window operates and can be from 1 to 24 hours. For a daily blackout window the maximum number of hours you can select is 23. This prevents you from inadvertently scheduling a 24/7 blackout.

  3. Click OK.
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