1. Database Migration Workbench Guide
  2. Database Consolidation

2 Database Consolidation

The following sections cover topics that are common to host and database consolidations:

How Enterprise Manager Consolidation Analyzes a Consolidation Scenario

To analyze a consolidation scenario, Enterprise Manager Consolidation follows a defined process.

For host consolidations, Enterprise Manager Consolidation estimates the hourly and overall resource requirements for each of the consolidation sources. Using metric data collected by Enterprise Manager, it calculates the requirement for each hour and for all hours (in the specified collection days), selecting the average, 80th percentile, or maximum value, depending on the selected resource allocation style (Aggressive, Medium, or Conservative).

For database consolidations, Enterprise Manager Consolidation uses the Ultra Conservative resource allocation style, which selects the maximum value of the resource over the entire time period.

Enterprise Manager Consolidation adjusts the value if a scale factor is specified. It further adjusts memory requirements in D2D scenarios by reducing the portion of memory used for the SGA by 50%, 40% or 30%, again depending on the resource allocation style. The resource requirement displayed for the source is the overall requirement determined by the resource allocation style and adjustments.

If the consolidation scenario includes existing destinations, Enterprise Manager Consolidation performs a similar calculation to determine the hourly and overall usage values for each destination. It does not scale or otherwise adjust these values, but calculates them using average, 80th percentile, or maximum values depending on the resource allocation style.

For host consolidations into new or existing destinations, Enterprise Manager Consolidation matches the hourly requirements for each source against the available hourly capacity of a destination. (Existing destinations start this process populated with their existing hourly workloads; new destinations start in an empty state.) If the destination can accommodate all hourly requirements for all resources, a successful consolidation occurs.

For database consolidations, Enterprise Manager Consolidation adds together the single workload values for each source database to determine which databases map to each destination.

If any requirement cannot be consolidated, Enterprise Manager Consolidation tries the next destination until one is found with sufficient capacity. If the consolidation is to existing destinations and none have sufficient remaining capacity, the source is excluded from the consolidation. For consolidation to new destinations, another destination is created to accommodate the source.

  • For D2D scenarios with RAC database destinations, where the workload is shared across multiple instances, the process differs. Each source database's workload is consolidated onto all instances in the RAC database, and the total workload is balanced across all instances. This is also true for D2S scenarios with Exadata or cluster destinations.

  • For D2D scenarios with Container database (CDB) destinations, each source database is consolidated to a separate pluggable database (PDB) within the CDB. Source databases that are in conflict due to user-specified constraints are consolidated to separate CDBs.

  • By default, Enterprise Manager Consolidation consolidates sources to the fewest possible destinations. However, for scenarios with multiple existing destinations, you can choose to spread the workload across all destinations instead.

The scenario Mapping page displays the results of the consolidation. The contents of this page vary depending on the project type and the resources selected for consolidation, but in general displays the following:

  • Projected destinations, and the sources consolidated to each destination.

  • For each resource, the capacity of the destination, together with the percentage and amount of that resource that will be consumed by the sources consolidated to it and existing workload, if any. Enterprise Manager Consolidation estimates this amount by finding the largest hourly usage for the resource on the destination. The source line shows the percentage of the destination's resources that will be used by that source.

Managing Data Collections

Manage data collections by viewing the status of your host or database projects.

  1. On the respective Consolidation home page select View Data Collection from the Actions menu.
  2. The view lists sources within a project where you can perform the following tasks:

    • View the latest collection status by project.

    • Select a source to see its collection history and troubleshoot potential problems with the collection.

    • Click the link under Data Collection Jobs to go to the job activity page where you can view and administer the latest data collection job.

    • Update the latest CPU performance metric values by following the instructions to download a CSV file with the latest rates. After downloading the file, click Browse to locate the file in the local file system and click Load to update the rates in Enterprise Manager Consolidation.

Viewing Consolidation Reports

You can repurpose consolidation project and scenario details in report form that you can capture in a variety of formats and distribute to a wider audience, as described in the following sections:

Viewing Consolidation Project Reports

To view a project report, select the host or database project on the respective Consolidation home page and click the Report button above the table. The report page repurposes project details as stacked, scrollable tables representing the tabbed information that appears in the project's details on the home page.

Click Publish Report to capture report contents. This action integrates with BI Publisher, where you can:

  • Save reports in a variety of formats (Excel, PowerPoint, HTML, PDF).

  • Distribute generated reports to e-mail lists (users who do not have access to Enterprise Manager, for example) on a defined schedule.

Click OK to return to the Consolidation home page.

Viewing Consolidation Scenario Reports

To view a project scenario report, select the host or database scenario within the project on the Consolidation home page and click the Report button above the table. The report page repurposes scenario details as stacked, scrollable tables representing the tabbed information that appears in the scenario's details on the home page.

Click Publish Report to capture report contents. This action integrates with BI Publisher, where you can:

  • Save reports in a variety of formats (Excel, PowerPoint, HTML, PDF).

  • Distribute generated reports to e-mail lists (users who do not have access to Enterprise Manager, for example) on a defined schedule.

Click OK to return to the Consolidation home page.

About Oracle Compute Cloud Shapes

A shape defines the number of Oracle Compute Units (OCPUs) and the amount of RAM available for an instance. An OCPU provides the equivalent CPU capacity of the current 3.0 GHz 2012 Intel Xeon processor with hyper threading enabled. Each OCPU corresponds to two hardware execution threads, known as vCPUs.

A wide range of shapes is available to help you select a combination of processing power and memory for your instances that best suits your business requirement. While selecting a shape for your instance, consider the nature of applications that you will deploy on the instance, the number of users that you expect to use the application, and also how you expect the load to scale in the future. Remember to also factor in the CPU and memory resources that will be used by the OS.

To determine the shape that meets your resource requirements, you may want to experiment with a shape and test it with a representative workload.

For complete information see Oracle Cloud Infrastructure.