Capacity-on-demand (CoD) refers to an Exadata database server that is installed with a subset of its cores turned off so that the database software license cost can be reduced. The reduction is implemented during software installation using Oracle Exadata Deployment Assistant (OEDA). The number of active cores can be increased at a later time, when more capacity is needed. CoD does not apply to Oracle Exadata storage server cores.
Note the following restrictions regarding capacity-on-demand:
Capacity-on-demand is available for X4-2, X4-8, and later systems.
Oracle Exadata Database Machine X4-2 Eighth Rack is excluded from capacity-on-demand, but the X5-2 Eighth Rack and X6-2 Eighth Rack are eligible for CoD.
Reducing the number of active cores lowers the initial software licensing cost. It does not change the hardware cost.
For X7-2 systems, the minimum number of cores that must be enabled is 14 per database server. Note that for the X7-2 Eighth Rack the minimum is 8 cores per database server.
For X6-2 systems, the minimum number of cores that must be enabled is 14 per database server. Note that for the X6-2 Eighth Rack the minimum is 8 cores per database server.
For X5-8 and X6-8 systems, the minimum number of cores that must be enabled is 56 per database server.
The minimum number of cores that must be enabled is 40% of the physical cores on each database server for X5-2 systems, and 50% for earlier systems.
For X4-2 systems, the minimum number of cores that must be enabled is 12 per database server.
For X4-8 systems, the minimum number of cores that must be enabled is 48 per database server.
For X5-2 systems, the minimum number of cores that must be enabled is 14 per database server. Note that for the X5-2 Eighth Rack the minimum is 8 cores per database server.
Additional cores are increased in 2-core increments per database server on X4-2 and later two-socket systems, and in 8-core increments on X4-8 and later eight-socket systems.
Within the same Exadata system, each database server can be licensed to a different number of cores, but each server in the same cluster should have the same number of active cores to accommodate a cluster failover without significant performance impact.
Capacity-on-demand may only be used to decrease the number of active cores during initial installation. After initial installation, the active core count may be increased, but not decreased. It is the customer's responsibility to acquire the additional software licenses. For steps on how to increase the number of active cores, refer to Oracle Exadata Database Machine Maintenance Guide.
The one exception to this is when you are adding database servers to an Exadata configuration, and you are redistributing the active cores in order to maintain a balanced cluster configuration. In that case the total number of active cores across all database servers cannot decrease and the end state must comply with the CoD rules. For example, if you have a quarter rack X5-2 with all cores active on both database servers (a total of 72 active cores) and you add a third database server with 18 active cores (a total of 90 cores), you can distribute the 90 active cores across all three database servers (30 active cores on each database server). That entails reducing the active cores on the two previous database servers from 36 to 30, and installing the new database server with 30 active cores. For database servers in a cluster, it is recommended that they each have the same or very similar compute capacity.
When you run Oracle Exadata Deployment Assistant (OEDA) to perform initial configuration of your Exadata system, you have to specify whether or not you are using CoD, and, if you are, the number of cores that you want to activate on your system. Because it is not possible to decrease the number of active cores after installation, other than the exception case mentioned above, it is recommended that you review the licensing plan to make sure you specify in OEDA the correct number of active cores you intend to license.
See Also:Oracle Exadata Database Machine Maintenance Guide for more information about capacity-on-demand core processor configurations.
To use the capacity-on-demand feature, the Exadata system must be running an approved monitoring tool so that the number of active cores can be validated.
The monitoring tool must be installed within three months of installation. To meet this requirement, you can do any of the following:
Purchase the Oracle technical support services necessary to enable eligibility for Oracle Platinum Services, and then continuously maintain those services.
Install, and then continuously utilize Oracle Configuration Manager in connected mode.
Install, and then continuously utilize Oracle Enterprise Manager in either connected or disconnected mode.
For running Oracle Enterprise Manager in disconnected mode, the base installation collects appropriate information from the server system, including the number of active cores. No add-on packs need to be purchased. The rules for using Oracle Enterprise Manager are the same as those that apply to Oracle Trusted Partitions. This is the only method that allows for disconnected mode.
Exadata permits the use of Trusted Partitioning, where the use of Oracle VM Server to limit the number of Oracle Processor licenses required, is allowed. That means any Oracle software running in a VM only needs to be licensed for the number of cores assigned to that VM, subject to a minimum core requirement equal to Capacity on Demand. For example, consider an X6-2 Quarter Rack database server that runs two databases, each in an 8-core VM, for a total of 16 licensed cores (the minimum is 14). Both databases also run options for Oracle Real Application Clusters (Oracle RAC) and Oracle Partitioning. The second database also runs the Oracle Advanced Security option. For the second database server, the required licensing must include 16 cores (8 processor licenses) of Oracle Database Enterprise Edition, Oracle RAC and Oracle Partitioning, and 8 cores (4 processor licenses) of Oracle Advanced Security option.
Oracle's Trusted Partitioning policy requires use of Oracle Enterprise Manager.
For purposes of licensing Oracle programs in a Trusted Partition, note the following:
Two virtual CPUs (vCPUs) are counted as equivalent to a physical core.
With the core factor of 0.5, one Oracle program processor license allows you to use 2 physical cores.
To use Trusted Partition on Oracle Exadata systems, they must be running Oracle Exadata System Software 184.108.40.206.0 or later.
The following table shows the licensing requirements and examples for Oracle Trusted Partitions for Oracle Exadata systems.
|Oracle Exadata System||Oracle Trusted Partition Licensing Requirements|
X6 and later
Minimum number of cores that must be licensed for an Eighth Rack system: 8 physical cores per compute node
Minimum number of cores that must be licensed for all other configurations: 14 physical cores per compute node
Oracle Exadata Database Machine X6-2 Quarter Rack has 2 compute nodes, each with two 22 core processors, for a total of 44 licensable physical cores per compute node.
At least 7 Oracle software processor licenses (equivalent to 14 physical cores based on the current core factor of 0.5) per compute node must be licensed. Since the quarter rack has 2 compute nodes, this means at least 14 Oracle software processor licenses must be licensed.
28 cores allow the customer to run 56 virtual CPUs (vCPUs).
X2 to X5
Minimum number of cores that must be licensed: 40% of the physical cores
Oracle Exadata Database Machine X5-2 Quarter Rack has 4 processors with 18 cores each, for a total of 72 licensable physical cores.
At least 14 Oracle software processor licenses (equivalent to 28 physical cores based on the current core factor of 0.5) must be licensed.
28 cores allow the customer to run 56 vCPUs.