About Life Cycle Management of Oracle Java Cloud Service Instances

With a few clicks of the mouse, you can create a WebLogic Server production environment in the cloud that is based on best practices, optimized for high performance and reliability, and is integrated with your infrastructure schema database and Oracle Cloud Infrastructure Object Storage.

When you create an Oracle Java Cloud ServiceOracle Java Cloud Service instance, you create and configure a Oracle Fusion Middleware Infrastructure domain with the resources defined in the following table.

Resources	Description
Administration Server	Operates as the central control entity for the configuration of the entire domain. It maintains the domain's configuration documents and distributes changes in the configuration documents to Managed Servers. Each Oracle Java Cloud Service instance has one server instance that hosts the Administration Server.
Managed Servers	Host business applications, application components, Web services, and their associated resources. When creating a service instance, you can configure up to four Managed Servers, then scale out, as needed. Each Oracle Java Cloud Service instance has one or more Managed Servers, each hosted on its own Virtual Machine (node). By default, the Managed Servers are named as follows: `first8charsOfDomainName_wls_n` (where `n` starts with 1 and is incremented by 1 for each additional Managed Server to to ensure that the names are unique).
Cluster	Consists of multiple Managed Servers running simultaneously and working together to provide increased scalability and reliability. In a cluster, most resources and services are deployed identically to each Managed Server (as opposed to a single Managed Server), enabling failover and load balancing. A cluster is configured automatically for a production-level service instance. By default, the cluster name will be generated from the first eight characters of the Oracle Java Cloud Service instance name using the following format: `first8charsOfServiceInstanceName_cluster`.
Load Balancer	It is recommended that you enable a load balancer when you configure more than one Managed Server in your environment. Enabling the load balancer is optional.

When Oracle Coherence is enabled for a service instance, additional resources related to Coherence are defined in a domain.

Resources	Description
Managed Servers (Coherence data tier, storage-enabled)	Each Oracle Java Cloud Service—Coherence instance has a Coherence data tier cluster, in which one or more Virtual Machines (nodes) can have one or more Managed Servers each. By default, the storage-enabled Managed Servers are named as follows: `first8charsOfDomainName_server_n_DG` (where `n` is a number that’s incremented by 1 for each additional Managed Server to guarantee unique names). The storage-enabled Managed Servers are responsible for storing and distributing data (both primary and backup) on the cluster. Coherence artifacts (such as Coherence configuration files, POF serialization classes, filters, entry processors, and aggregators) are packaged as a GridARchive (GAR) and deployed on the Managed Servers. Note that when you stop or start a service instance, all the nodes for the Managed Servers on the Coherence data tier will also stop or start. If stopped, all data in the Coherence cache will be lost.
Managed Servers (Application tier, storage-disabled)	The storage-disabled Managed Servers (identified by the name format `first8charsOfDomainName_server_n`) in the first WebLogic Server cluster host Coherence applications (cache clients), and are not responsible for storing data. Clients in the application tier are deployed as EARs. Coherence artifacts (such as Coherence configuration files, POF serialization classes, filters, entry processors, and aggregators) are packaged as a GridARchive (GAR) and deployed within an EAR.
Cluster (Coherence data tier)	A second WebLogic Server cluster is configured in the domain for storing and distributing data. The Coherence data tier cluster is associated with the Coherence cluster `DataGridConfig`. The cluster members are storage-enabled by default. By default, the cluster name will be generated from the first eight characters of the service instance name using the following format: `first8charsOfServiceInstanceName_DGCluster`.
Cluster (Application tier)	The first WebLogic Server cluster (identified by the name format `first8charsOfServiceInstanceName_cluster`) is referred to as the application tier cluster. The cluster is also associated with the Coherence cluster `DataGridConfig`, and the cluster members are storage-disabled by default.
Coherence Cluster	The system-level resource (`CoherenceClusterSystemResource`) has the default name `DataGridConfig`. Both the application tier WebLogic Server cluster (storage-disabled) and the data tier WebLogic Server cluster (storage-enabled) are associated with the Coherence cluster.

For more information about WebLogic domains, see:

Oracle Fusion Middleware 12.2.1: WebLogic Server Domains in Understanding Oracle WebLogic Server
Oracle Fusion Middleware 11.1.1.7: Understanding Oracle WebLogic Server Domains in Understanding Domain Configuration for Oracle WebLogic Server.
When Oracle Coherence is enabled for a service instance: (Oracle Fusion Middleware 12.2.1) Configuring and Managing Coherence Clusters in Administering Clusters for Oracle WebLogic Server.

After the Oracle Java Cloud Service instance is created, the Administration Server in the domain is started automatically. You can deploy applications and manage the domain resources using the standard administration tools, including Enterprise Manager Fusion Middleware Control, Oracle WebLogic Server Administration Console, Oracle WebLogic Scripting Tool (WLST), Node Manager, and Oracle Traffic Director Console.

You can stop, start, or restart a service instance or individual nodes by using the Oracle Java Cloud Service Console, PaaS Service Manager CLI, or REST API. For example, you can stop service instances or individual server nodes to stop metering for these resources, or restart the Administration Server or individual server nodes if reboot is needed.

A sample application is deployed automatically when the service instance is created. For more information, see About the Sample Application Deployed to an Oracle Java Cloud Service Instance.

Note:

If you extend your domain using the administration tools, for example, to add an additional cluster, you are responsible for maintaining those additional resources.