Naming Considerations Administration Server Considerations
11.5 Application Deployment Considerations
Deploy clusterable objects to the cluster, rather than to individual Managed Servers in the cluster. For information and recommendations, see Deploying Applications to Oracle WebLogic Server.11.6 Architecture Considerations
For information about alternative cluster architectures, load balancing options, and security options, see Chapter 9, Cluster Architectures.11.7 Avoiding Problems
The following sections present considerations to keep in mind when planning and configuring a cluster.11.7.1 Naming Considerations
For guidelines for how to name and address server instances in cluster, see Section 10.1.5, Identify Names and Addresses.11.7.2 Administration Server Considerations
To start up WebLogic Server instances that participate in a cluster, each Managed Server must be able to connect to the Administration Server that manages configuration information for the domain that contains the cluster. For security purposes, the Administration Server should reside within the same DMZ as the WebLogic Server cluster. The Administration Server maintains the configuration information for all server instances that participate in the cluster. The config.xml file that resides on the Administration Server contains configuration data for all clustered and non-clustered servers in the Administration Servers domain. You do not create a separate configuration file for each server in the cluster. The Administration Server must be available in order for clustered WebLogic Server instances to start up. Note, however, that once a cluster is running, a failure of the Administration Server does not affect ongoing cluster operation. Singleton Services Java EE APIs used to implement singleton services include: ■ JMS Destinations, ■ JTA transaction managers ■ Cached entity beans with pessimistic concurrency control Scalability can be increased by partitioning the service into multiple instances, each of which handles a different slice of the backing data and its associated requests WebLogic Server features for increasing the availability of singleton services include: ■ Support for multiple thread pools for servers, to harden individual servers against failures ■ Health monitoring and lifecycle APIs to support detection restart of failed and ailing servers ■ Ability to upgrade software without interrupting services ■ Ability to migrate JMS servers and JTA transaction recovery services. Table 11–3 Cont. Java EE and WebLogic Support for Service Types Service Java EE Support WebLogic Server Scalability and Reliability Features for... 11-10 Using Clusters for Oracle WebLogic Server The Administration Server should not participate in a cluster. The Administration Server should be dedicated to the process of administering servers: maintaining configuration data, starting and shutting down servers, and deploying and undeploying applications. If the Administration Server also handles client requests, there is a risk of delays in accomplishing administration tasks. There is no benefit in clustering an Administration Server; the administrative objects are not clusterable, and will not failover to another cluster member if the administrative server fails. Deploying applications on an Administration Server can reduce the stability of the server and the administrative functions it provides. If an application you deploy on the Administration Server behaves unexpectedly, it could interrupt operation of the Administration Server. For these reasons, make sure that the Administration Servers IP address is not included in the cluster-wide DNS name.11.7.3 Firewall Considerations
Parts
» Oracle Fusion Middleware Online Documentation Library
» Document Scope and Audience Guide to this Document
» What Are the Benefits of Clustering? What Are the Key Capabilities of a Cluster?
» Servlets and JSPs EJBs and RMI Objects
» Getting Connections with Clustered JDBC Failover and Load Balancing for JDBC Connections
» Pure-Java Versus Native Socket Reader Implementations
» Client Communication via Sockets
» How WebLogic Server Creates the Cluster-Wide JNDI Tree
» How WebLogic Server Updates the JNDI Tree Client Interaction with the Cluster-Wide JNDI Tree
» Load Balancer Configuration Requirements Load Balancers and the WebLogic Session Cookie
» Related Programming Considerations How Session Connection and Failover Works with a Load Balancer
» Round-Robin Load Balancing Weight-Based Load Balancing
» Transactional Collocation Optimization for Collocated Objects
» Methods of Configuring Clusters Load Balancing for JDBC Connections
» Using Replication Groups HTTP Session State Replication
» Connection with Load Balancing Hardware Failover with Load Balancing Hardware
» Configuration Requirements for Cross-Cluster Replication
» Configuring Session State Replication Across Clusters
» Clustering Objects with Replica-Aware Stubs
» Failover and JDBC Connections Understanding Server and Service Migration
» Migration Terminology Oracle Fusion Middleware Online Documentation Library
» Features That Use Leasing Leasing Versions
» Determining Which Type of Leasing To Use High-availability Database Leasing
» Non-database Consensus Leasing Leasing
» Preparing for Automatic Whole Server Migration
» Configuring Automatic Whole Server Migration
» Startup Process in a Cluster with Migratable Servers
» Automatic Whole Server Migration Process
» Manual Whole Server Migration Process Administration Server Role in Whole Server Migration
» Migratable Server Behavior in a Cluster Node Manager Role in Whole Server Migration
» Cluster Master Role in Whole Server Migration
» JMS-related Services JTA Transaction Recovery Service
» Custom Store Availability for JMS Services Default File Store Availability for JTA
» Best Practices for Targeting JMS when Configuring Automatic Service Migration
» Architecture Web Application Tiers
» Combined Tier Architecture De-Militarized Zone DMZ Load Balancer Proxy Plug-In
» No Collocation Optimization Firewall Restrictions
» Multi-Tier Proxy Architecture Proxy Architecture Benefits Proxy Architecture Limitations
» Proxy Plug-In Versus Load Balancer
» DMZ with Two Firewall Configuration
» Dynamic Cluster Address If you do not explicitly define a cluster address
» Configuration Roadmap Install WebLogic Server
» Starting a WebLogic Server Cluster
» Configure Node Manager Configure Load Balancing Method for EJBs and RMIs
» Sample web.xml This section contains a sample deployment descriptor file
» Accessing Applications Via the Proxy Server Ensure that applications clients will
» Configure Replication Groups Configure Migratable Targets for Pinned Services
» Migrating When the Currently Active Host is Unavailable Use this migration
» Configure Multicast Time-To-Live TTL Configure Multicast Buffer Size
» Cluster-Related Configuration Options Follow Usage and Configuration Guidelines
» Manual Migration of the JTA Transaction Recovery Service State Management in a Cluster
» Naming Considerations Administration Server Considerations
» Firewall Considerations Avoiding Problems
» Check the Server Version Numbers Check the Multicast Address Check the CLASSPATH Value
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