Key Concepts and Terminology

The following concepts and terminology will help you get started with Java Management Service. The Oracle Cloud Infrastructure documentation provides related terminology.

Application

An application refers to a Java program.

The name of an application is derived from the fully-qualified name of its main class by default. An application can run on multiple Java runtimes.

Compartment

A compartment enables you to organize and control access to your cloud resources, such as a Fleet or Configuring Managed Instances. A compartment should be thought of as a logical group and not as a physical container.

For more details, see OCI Key Concepts and Terminology.

Compute Instance

A Compute Instance is a host that is provisioned and managed by Oracle Cloud Infrastructure. For more information, see Overview of the Compute Service.

Deployed Application

An application or Java program that is deployed on a Java server.

Fleet

A fleet is the primary collection with which you interact when using JMS . It contains Managed Instances that share rules and policies.

Installation

An installation refers to Java Runtime installation on one or more hosts.

An installation is identified by four attributes:
  • File system path, such as /usr/lib/jvm/jdk13.0.1/
  • Vendor, such as Oracle Corporation
  • Operating system, such as Linux
  • Architecture, such as x64

Java Runtime

A Java Runtime Environment (JRE, or Java Runtime) is a Java Virtual Machine (JVM), Java platform core classes, and supporting Java platform libraries. It's released as a certain version of a distribution or included with a vendor's product release. A Java Runtime can be installed to run a single Application or to be used by many applications.

A Java Runtime is identified by three attributes:
  • Vendor, such as Oracle Corporation
  • Distribution name, such as OpenJDK Runtime Environment
  • Version, such as 1.8.0_282

When displayed by JMS, a Java Runtime from Oracle indicates if it requires an update.

Java Server

There are two types of Java servers:

  • Web server: A web server delivers static web content such as HTML pages, files, images, videos in response to hypertext transfer protocol (HTTP) requests from a web browser. The web servers handle only HTTP requests and responses.

    Example: Apache Tomcat

  • Application server: An application server enables interaction between end-user clients and server-side application code (business logic) to generate and deliver dynamic content. The client for an application server can be an end-user UI, mobile application, web browser, and so on. The client-server interaction can happen through various communication protocols, including HTTP.

    Examples: WebLogic, JBoss

JMS supports Apache Tomcat, JBoss, and WebLogic.

JMS Plug-in

Java Management Service (JMS) plug-in allows JMS to interact with hosts and send the data back to the cloud service.

JMS plug-ins are provided by Oracle Management Agent and Oracle Cloud Agent for OCI Compute Instances. Deploy JMS plug-ins on:

A host that contain deployed JMS plug-ins is a Managed Instance.

Log Configuration

JMS uses the OCI Logging service to store inventory, operation logs and crypto analysis logs. Inventory logs are Custom Logs that store the Java Runtime inventory and usage related information reported from the hosts by Configuring Managed Instances. Operation logs are custom logs for storing the logs related to operations carried out through JMS. Each fleet has its own unique inventory and operation log. Crypto analysis logs are custom logs that hold results of a crypto analysis performed on the fleet. Logs are placed under a Log Group. By relying on logs and JMS reports, you can do additional analytics using Logging Analytics.

Managed Server

Managed Servers host business applications, application components, web services, and their associated resources.

You can deploy web applications, web services, and other resources onto the Managed Servers and use the Administration Server only for configuration and management purposes.

As an example, see Managed Servers and Managed Server Clusters.

Managed Instance

A Managed Instance is a host that contains deployed JMS plug-ins. Hosts can be any computer running in your enterprise, either on premise or in the cloud. A managed instance has a unique identity that's used by JMS to distinguish it from other managed instances and can only be part of a single Fleet at any given time.

Oracle Cloud Agent

An Oracle Cloud Agent (OCA) is a lightweight process that manages plug-ins running on a compute instance, also known as host or VM, residing in the Oracle Cloud Infrastructure. You can deploy JMS plug-ins on compute instances using the Oracle Cloud Agent.

For more information, see Managing Plugins with Oracle Cloud Agent.

Oracle Management Agent

Management Agent is installed on a host. It allows the JMS plug-ins to monitor and collect data from the sources that reside on hosts or virtual hosts.

The management agent cloud service is an OCI service that manages management agents and their life cycle. For more details, see Management Agent Concepts.

Tag

A tag is a key-value pair that you use to add metadata to your OCI resources.

JMS uses a tag in the namespace jms with the key fleet_ocid to identify the contents of a fleet. The managed instances contained in a fleet are identified by the tag value corresponding to the OCID of the fleet. (For more information, see Create Fleet.)

For a more detailed description of tags, see Tagging Overview.

Tenancy

When you sign up for Oracle Cloud Infrastructure, Oracle creates a tenancy for you or your enterprise. This is a secure and isolated partition within Oracle Cloud Infrastructure where you can create, organize, and administer your cloud resources.

Work Request

A Work Request allows you to monitor long-running operations such as Java Runtime Lifecycle Management operations. When you launch such an operation, JMS creates a work request. A work request is an activity log that enables you to track each step in the operation's progress. Work requests are helpful in the following scenarios:
  • If an operation fails, a Work Request can help you determine which step of the process had an error.
  • Some operations affect multiple resources. For example, a delete Java Runtime operation could affect multiple Java Runtimes, Java Runtime installation paths and Managed Instances. A work request provides a list of the resources that an operation affects.