One of the significant features of Oracle Weblogic 12.2.1 is support for multi-tenancy. Oracle WebLogic Server Multitenant provides maximum application portability, 3X consolidation with a shared application platform, and application isolation and independence, all in an end-to-end integrated solution.
The key benefits of a multitenancy (MT) in Weblogic are :
Microcontainers : Domain partitions act like microcontainers, encapsulating applications and the resources (datasources, JMS servers, etc) they depend on. Partitions are isolated from each other, so that applications in one partition do not disrupt applications running in other partitions in the same server or domain. This results in :
-Max portability between environments
-Parity between development and production
-Fast start up/shutdown – disposability
-Easy scale up
-Enable migration to cloud
Logical Virtualization within the application server : It includes administrative constructs and infrastructure, including pluggable partitions,that enable you to share domains for many applications. By pushing virtualization higher in the technology stack, more of the stack can be shared. More sharing results in better efficiency.
Isolation : Virtualization within the application server naturally implies some form of isolation between the applications running on the shared platform. For WebLogic Server Multitenant, Oracle built several forms of isolation that are critical for consolidating independent applications into a shared domain. These isolations are :
-Runtime and resource management (JDK and WLS partnership, runtime resources like Heap, CPU, threads, request)
-Administrative (Admin roles, lifecycle troubleshooting for every partition)
-Security/Identity (realms, users per partition, separate authentication and authorization providers.)
-Traffic/data (dedicated JNDI segregated data, dedicated and shared coherence caches )
End-to-End Integration : Multitenancy provides end-to-end integration and ease of use with OracleTraffic Director, Oracle Coherence, and Oracle Database 12c pluggable databases. WebLogic Server MT lifecycle management links together partitions across different components to form one cohesive unit that serves a tenant’s needs. To do this, the lifecycle manager provides configuration integration across components.
Some of the key additions to WebLogic for multi-tenancy are in the configuration and runtime areas where they have added domain partitions,resource groups, and resource group templates.
A domain partition (partition for short) is an administrative and runtime slice of a WebLogic domain. In many ways you can think of a partition as a WebLogic micro-container. Domain Partition allows you to group together various resources and applications. This concept of partition is also extended to coherence. Every partition has its own work manager configurations. Each partition will contain its own apps and resources . You can target each partition to a managed server cluster where you want the partition’s apps and resources to run. You can start and shut down each partition independently, even if you have targeted multiple partitions to the same cluster. You can have different partitions use different security realms.Plus, for each partition you can identify partition administrators who can control that partition.
Virtual host defines how partition is accessible from external world. This information is automatically registered in Oracle traffic director.
Virtual target defines where partition runs and how to access or targeted to server/cluster
Resource group is collection of applications and resources managed together, created within a partition, targeted to virtual target.
In 12.1.3 and before the typical topology of WLS is as follows:
You define managed servers and security realms in the domain and you deploy apps and resources to the domain.
In 12.2.1 , the WLS topology looks like this :
- In a partition resources and applications are grouped into resource groups, and it is the resource group that is targeted. When a target is set on a resource group it applies to all of the resources and applications inside of the resource group (you don’t target them individually).
Targeting of Virtual targets , partition and Resource Group to Cluster:
– For every Partition you assign a Virtual Target which is mapped to a particular cluster.
Thus using multitenancy, different applications (or tenants) can share the same server JVM (or cluster), and the same WebLogic domain, while maintaining isolation from each other by running in separate domain partitions.
- In this release of WebLogic Server MT, only Java EE applications are supported. Products that depend on Oracle JRF (Java Required Files) are not supported.
- MT only available in Suite or EE version
For more detailed information about multi tenancy, please see this link