WebSphere Virtual Enterprise in a micro-partitioned environment

You can use WebSphere® Virtual Enterprise in a micro-partitioned environment. WebSphere Virtual Enterprise can understand the utilization of shared processor partitions.

Terminology for server virtualization on POWER AIX systems

You must understand the following terms when you are using WebSphere Virtual Enterprise on a POWER® AIX® system:
Logical partitioning
The ability to divide the resources of a system to create multiple separate servers. Each server runs its own operating system.
Micro-partitioning
The ability to share a pool of physical processors across multiple logical partitions. Physical processors can be allocated to a partition in increments of 0.01 of a processor with a minimum of 0.10 of a processor.
Shared processor partition
A partition that is configured to use a shared processor pool. A shared processor partition is a type of micro-partition.
Entitled capacity
The percentage of processor usage that is granted to a partition; specified in terms of 0.01 of a processor with a minimum of 0.10 of a processor.
Capped partition
A partition that cannot be granted more processing units beyond the configured entitlement for the partition.
Uncapped partition
A partition that can exceed its configured entitlement when needed, if resources permit.

Entitled capacity

A shared processor partition has a metric called Entitled Capacity Percentage. This metric represents the percentage the partition is using of its entitlement at a given point in time. The metric is visible in popular AIX system monitoring tools like the lparstat command, the nmon command, and the topas command.

An uncapped, shared processor partition can be assigned more processing capacity beyond its entitlement. The amount of processing capacity above its entitlement depends on the availability of processors in the shared pool and the maximum amount that the virtual processor configuration allows.

WebSphere Virtual Enterprise and shared processor partitions

WebSphere Virtual Enterprise Version 6.1.1 and later can understand the utilization of shared processor partitions and the dynamic capacity of the shared processor pool on the physical hardware that is required to operate in a shared processor partition environment.

WebSphere Virtual Enterprise operates in an uncapped, shared micro-partition environment by understanding two important metrics for each partition: WebSphere Virtual Enterprise calculates and uses these metrics so that the product can understand the utilization and dynamic capacity of a shared micro-partition.

WebSphere Virtual Enterprise and the entitled capacity percentage

The entitled capacity percentage represents the percentage the partition is using of its entitlement at a given point in time. This value represents the amount of processing power that is being used by that partition. WebSphere Virtual Enterprise publishes the value from each node agent or middleware agent process every 15 seconds for use by WebSphere Virtual Enterprise autonomic controllers such as the work profiler and dynamic workload manager (DWLM).

WebSphere Virtual Enterprise and the maximum entitled capacity percentage

When running on an uncapped, shared micro-partition, the maximum processing power of that partition is not fixed. In other words, the POWER Hypervisor™ can assign more processing power from the shared processing pool to a partition so that it is using more than its configured entitled capacity. For WebSphere Virtual Enterprise to understand the dynamic processor capacity, it calculates and publishes a metric called maximum entitled capacity percentage. This value represents the maximum percentage of its entitlement that a partition can use.

WebSphere Virtual Enterprise publishes the value from each node agent or middleware agent process every 15 seconds for use by WebSphere Virtual Enterprise autonomic controllers, such as the autonomic request flow manager (ARFM) and the application placement controller (APC). The maximum entitled capacity percentage value is calculated from the idle cycles of the shared processor pool to which the partition belongs. As the utilization of the shared processor pool increases and decreases, the maximum entitled capacity percentage value also changes.

WebSphere Virtual Enterprise metrics for shared processor partitions

WebSphere Virtual Enterprise can recognize additional statistics that are specific to uncapped, shared processor partitions. . These statistics can help you understand the utilization of a shared processor partition and the dynamic capacity of the shared processor pool. These statistics are helpful in monitoring WebSphere Virtual Enterprise when you are operating in a micro-partitioned environment.
Entitled capacity percentage
Represents the percentage of its entitlement that the partition is using.
Maximum entitled capacity percentage
Represents the maximum percentage of its entitlement that a partition can use.
Shared partition CPU utilization
Represents the processor utilization of an uncapped shared processor partition. The value of this statistic is calculated by the following formula:
(Entitled Capacity Percentage / Maximum Entitled Capacity percentage) x 100
Physical processors consumed
Represents the number of physical processors that are being used by the shared server partition.
Available pool processors
Represents the number of processors that are available in the shared processor pool to which this server partition belongs.
These statistics are saved in the NodeStatsHistoricCache log file. See NodeStatsHistoricCache for more information.For more information about this log file, see NodeStatsHistoricCache topic in the WebSphere Virtual Enterprise Version 6.1.1 Information Center.

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