Resources

All managed resources, which are called nodes, have an agent with a socket connection to the Orchestration Server. All resource use is metered, controlled, and audited by the Orchestration Server. Policies govern the use of resources.

The Orchestration Server allocates resources by reacting as load is increased on a resource. As soon as we go above a threshold that was set in a policy, a new resource is allocated and consequently the load on that resource drops to an acceptable rate.

You can also write and jobs that perform cost accounting to account for the cost of a resource up through the job hierarchy, periodically, about every 20 seconds. For more information, see Auditing and Accounting Jobs.

A collection of jobs, all under the same hierarchy, can cooperate with each other so that when one job offers to give up a resource it is reallocated to another similar priority job. Similarly, when a higher priority job becomes overloaded and is waiting on a resource, the system “steals” a resource from a lower priority job, thus increasing load on the low priority job and allocating it to the higher priority job. This process satisfies the policy, which specifies that a higher priority job must complete at the expense of a low priority job.

Users

An Orchestration user is an individual who authenticates to the Orchestration Server for the purpose of managing (that is, running, monitoring, canceling, pausing, stopping, or starting) a deployed job, or a user who authenticates through the to manage virtual machines. The Orchestration Server administrator can use the Orchestration Console to identify users who are running jobs and to monitor the jobs that are currently running or that have run during the current server session.

Orchestration Server users must authenticate to access the system. Access and use of system resources are governed by policies. For more information, see The User Object in the NetIQ Cloud Manager 2.1.5 Orchestration Console Reference.

Job Definitions

A job definition is described in the embedded enhanced Python script that you create as a job developer. Each job instance runs a job that is defined by the Job Definition Language (JDL). Job definitions might also contain usage policies.

Job Instances

Jobs are instantiated at runtime from job definitions that inherit policies from the entire context of the job (such as users, job definitions, resources, or groups).

Policies

Policies are XML documents that contain various constraints and static fact assignments that govern how jobs run in the Cloud Manager Orchestration environment.

Policies are used to enforce quotas, job queuing, resource restrictions, permissions, and other job parameters. Policies can be associated with any Orchestration Server object.

Facts

Facts represent the state of any object in the Orchestration Server grid. They can be discovered through a job or they can be explicitly set.

Facts control the behavior a job (or joblet) when it’s executing. Facts also detect and return information about that job in various UIs and server functions. For example, a job description that is set through its policy and has a specified value might do absolutely nothing except return immediately after network latency.

The XML fact element defines a fact to be stored in the Grid object’s fact namespace. The name, type and value of the fact are specified as attributes. For list or array fact types, the element tag defines list or array members. For dictionary fact types, the dict tag defines dictionary members.

Facts can also be created and modified in JDL and in the Java Client SDK.

There are three basic types of facts:

See the example, /opt/novell/zenworks/zos/server/examples/allTypes.policy. This example policy has an XML representation for all the fact types.

Constraints

The constraint element of a policy can define the selection and allocation of Grid objects (such as resources) in a job. The required type attribute of a constraint defines the selection of the resource type.

For example, in order for the Orchestration Server to choose resources for a job, it uses a “resource” constraint type. A resource constraint consists of Boolean logic that executes against facts in the system. Based upon this evaluation, the Orchestration Server considers only resources that match the criteria that have been defined in constraints.

Groups

Resources, users, job definitions and virtual machines (VM) are managed in groups with group policies that are inherited by members of the group.

VM: Hosts, Images, and Instances

A virtual machine host is a resource that is able to run guest operating systems. Attributes (facts) associated with the VM host control its limitations and functionality within the Orchestration Server. A VM image is a resource image that can be cloned and/or provisioned. A VM instance represents a running copy of a VM image.

Templates

Templates are images that are meant to be cloned (copied) prior to provisioning the new copy.

Controlling Process Flow

Jobs can written to control all operations and processes of managed resources. Through jobs, the Orchestration Server manages resources to perform work. Automated jobs (written in JDL), are broken down into joblets, which are distributed among multiple resources.

Parallel Processing

By managing many small joblets, the Orchestration Server can enhance system performance and maximize resource use.

Managing the Cluster Life Cycle

Jobs can detect demand and monitor health of system resources, then modify clusters automatically to maximize system performance and provide failover services.

Discovery Jobs

Some jobs provide inspection of resources to more effectively management assets. These jobs enable all agents to periodically report basic resource facts and performance metrics. In essence, these metrics are stored as facts consisting of a key word and typed-value pairs like the following example:

resource.loadaverage=4.563, type=float

Jobs can poll resources and automatically trigger other jobs if resource performance values reach certain levels.

The system job scheduler is used to run resource discovery jobs to augment resource facts as demands change on resources. This can be done on a routine, scheduled basis or whenever new resources are provisioned, new software is installed, bandwidth changes occur, OS patches are deployed, or other events occur that might impact the system.

Consequently, resource facts form a capabilities database for the entire system. Jobs can be written that apply constraints to facts in policies, thus providing very granular control of all resources as required. All active resources are searchable and records are retained for all off-line resources.

The following osInfo.job example shows how a job sets operating system facts for specific resources:

resource.cpu.mhz (integer) e.g., "800" (in Mhz)
    resource.cpy.vendor (string) e.g. "GenuineIntel"
    resource.cpu.model (string) e.g. "Pentium III"
    resource.cpu.family (string) e.g. "i686"

osInfo.job is packaged as a single cross-platform job and includes the Python-based JDL and a policy to set the timeout. It is run each time a new resource appears and once every 24 hours to ensure validity of the resources..

System Jobs

Jobs can be scheduled to periodically trigger specific system resources based on specific time constraints or events. As shown in the following figure, the Orchestration Server provides a built-in job scheduler that enables you or system administrators to flexibly deploy and run jobs.

Figure 1-4 The Job Scheduler

Provisioning Jobs

Jobs also drive provisioning for virtual machines (VMs) and physical machines, such as blade servers. Provisioning adapter jobs for various VM hypervisors are deployed and organized into appropriate job groups for management convenience.

The provisioning jobs included in the Orchestration Server are used for interacting with VM hosts and repositories for VM life cycle management and for cloning, moving VMs, and other management tasks. These jobs are called “provisioning adapters” and are members of the job group called “provisionAdapters.”

Auditing and Accounting Jobs

You can create Cloud Manager Orchestration jobs that perform reporting, auditing, and costing functions inside your data center. Your jobs can aggregate cost accounting for assigned resources and perform resource audit trails.