# Introducing WebLogic Operations Control

# Glossary

#### Action

A Java class that can display alert messages in the WLOC Administration Console, send notifications, or change the runtime state of a service. Actions can be adjudicated, requiring user input before WLOC invokes the action pipeline.
Actions can be invoked by the Controller as part of enforcing a policy, or manually from the WLOC Administration Console.

#### Action pipeline

A sequence of actions that WLOC invokes when a process operates beyond a constraint. Each policy can define at most one action pipeline. Action pipelines can be adjudicated, requiring user input before WLOC invokes the action pipeline.
Action pipelines can be invoked by the Controller as part of enforcing a policy, or manually from the WLOC Administration Console.

#### Agent

The WLOC component that interacts with the hosts of WLOC processes. Agents discover the computing resources that are available for allocation by WLOC, invoke commands on behalf of the Controller, and provide monitoring data to the Controller. WLOC includes the following types of Agents:

- Plain Agent for managing any type of Java process. A Plain Agent renders the resources from the machine on which it resides as a WLOC resource pool.
- ESX Agent for managing only virtualized Java applications that run on LiquidVM (LVM), such as WebLogic Server Virtual Edition (WLS-VE) running in a virtualized environment. An ESX Agent renders VMware resource pools as WLOC resource pools; it can reside on any machine in your operations center.

#### Application

See Service and Process.

#### Compute power

See CPU cycles.

#### Compute resource

See Resource pool.

#### CPU cycles

A measurement of the CPU resources that a resource pool can supply and that a service needs. The measurement is normalized across CPU architectures so that a megahertz of processing on an i386 processor is comparable to a megahertz on other types of processors.

#### Constraints

Runtime requirements that define the service level agreements (SLAs) for a service. When processes operate outside of constraints, policies can trigger actions or action pipelines.
WLOC provides preconfigured constraints and users can configure additional constraints. The preconfigured constraints enable users to place requirements on the most common and important measurements of health and performance. Users can configure additional constraints based on time or the values of MBean attributes. For resource pools that are managed by ESX Agents, users can configure constraints based on the consumption of resources.

#### Controller

The centralized component that gathers data from Agents about the operating environment and deployed services to deliver adaptive management; evaluates constraints; and issues instructions to Agents to carry out actions. The Controller hosts the WLOC Administration Console. Each WLOC environment contains a single Controller.

#### Hypervisor

Virtualization software that allows multiple operating systems to run on a single physical computer at the same time.

#### JMS

Java Message Service.

#### JVM

Java Virtual Machine.

#### JMX

Java Management Extensions.

#### WLOC environment

The collection of all resource pools, services, processes, Agents and Controller in a single installation of WLOC.

#### Machine

Either a physical machine or a virtual machine.

#### Managed environment

See WLOC Environment.

#### Metric

A numeric runtime value that describes the performance of a process or process group. Some metrics are aggregations or calculations of raw (observed) data. Policies set constraints on metrics.

#### Physical host

The physical machine that is hosting an Agent or a virtual machine.

#### Policies

Runtime requirements for a service and actions to take when the service operates outside the requirements. Each policy consists of two parts: a single constraint and an action or pipeline of actions. You can create multiple policies for each service. Policies can apply to all processes in a service, to a group of processes (process type), or to a single process.

#### Process

A program that WLOC manages. For example, a single WebLogic Server Managed Server is a process. From the perspective of WLOC, a Java process consists of an entire JVM stack and includes any application server and applications being managed by the Controller.

#### Process group

A collection of processes in a service for which policies can be written. For example, you can create a process group that contains three WebLogic Server instances. You can write a policy that starts all three server instances when the service is deployed. In addition, you can write a policy that increases a specific resource for all three servers when a constraint is surpassed.

#### Process type

See Process group.

#### Resource pool

A virtual environment in which you can deploy WLOC services. Each resource pool provides access to physical computing resources (such as CPU cycles, memory, and disk space) and pre-installed software that a service needs to run. A resource pool also contains a description of the failover capabilities of the machines that host the computing and software resources.

#### Rules

See Constraints.

#### Service

A collection of one or more processes that WLOC manages as a unit. Each process in a service is a software stack starting from the Java Virtual machine (JVM) and including the classes that are running in the JVM.
For example, you can create a service for managing a single WebLogic Server instance on which you have deployed a single Java EE application, or you can create a service for managing all WebLogic Server instances in a clusters. A service specifies:

- Requirements for the physical computing resources that are needed to run all of its processes. These resource requirements are expressed as a range of CPU cycles, memory, and disk space.
- An optional set of policies that define a service level agreement and actions to take when the service is operating outside of the SLA.
- Metadata that defines the Java classes or other executables that make up the service's processes. For more information, see Services.