Node Managers Role in Whole Server Migration Cluster Masters Role in Whole Server Migration
3.9.2.5 Migratable Server Behavior in a Cluster
A migratable server is a clustered Managed Server that is configured as migratable. These are the key behaviors of a migratable server: ■ If you are using a database to manage leasing information, during startup and restart by Node Manager, a migratable server adds a row to the lease table. The row for a migratable server contains a timestamp, and the machine where it is running. ■ When using a database to manage leasing information, a migratable server adds a row to the database as a result of startup, it tries to take on the role of cluster master, and succeeds if it is the first server instance to join the cluster. ■ Periodically, the server renews its lease by updating the timestamp in the lease table. By default a migratable server renews its lease every 30,000 milliseconds—the product of two configurable ServerMBean properties: – HealthCheckIntervalMillis, which by default is 10,000. – HealthCheckPeriodsUntilFencing, which by default is 3. ■ If a migratable server fails to reach the lease table and renew its lease before the lease expires, it terminates as quickly as possible using a Java System.exit—in this case, the lease table still contains a row for that server instance. For information about how this relates to automatic migration, see Section 3.9.2.7, Cluster Masters Role in Whole Server Migration. ■ During operation, a migratable server listens for heartbeats from the cluster master. When it detects that the cluster master is not sending heartbeats, it attempts to take over the role of cluster master, and succeeds if no other server instance has claimed that role.3.9.2.6 Node Managers Role in Whole Server Migration
The use of Node Manager is required for server migration—it must run on each machine that hosts, or is intended to host. Node Manager supports server migration in these ways: ■ Node Manager must be used for initial startup of migratable servers. When you initiate the startup of a Managed Server from the Administration Console, the Administration Server uses Node Manager to start the server instance. You can also invoke Node Manager to start the server instance using the stand-alone Node Manager client; however, the Administration Server must be available so that the Managed Server can obtain its configuration. Note: Migration of a server instance that was not initially started with Node Manager will fail. High Availability for WebLogic Server 3-13 ■ Node Manager must be used for suspend, shutdown, or force shutdown of migratable servers. ■ Node Manager tries to restart a migratable server whose lease has expired on the machine where it was running at the time of failure. Node Manager performs the steps in the server migrate process by running customizable shell scripts, provided with WebLogic Server, that start, restart and stop servers; migrate IP addresses; and mount and unmount disks. The scripts are available for Solaris and Linux. – In an automatic migration, the cluster master invokes Node Manager to perform the migration. – In a manual migration, the Administration Server invokes Node Manager to perform the migration.3.9.2.7 Cluster Masters Role in Whole Server Migration
In a cluster that contains migratable servers, one server instance acts as the cluster master. Its role is to orchestrate the server migration process. Any server instance in the cluster can serve as the cluster master. When you start a cluster that contains migratable servers, the first server to join the cluster becomes the cluster master and starts up the cluster manager service. If a cluster does not include at least one migratable server, it does not require a cluster master, and the cluster master service does not start up. In the absence of a cluster master, migratable servers can continue to operate, but server migration is not possible. These are the key functions of the cluster master: ■ Issues periodic heartbeats to the other servers in the cluster. ■ Periodically reads the lease table to verify that each migratable server has a current lease. An expired lease indicates to the cluster master that the migratable server should be restarted. ■ Upon determining that a migratable servers lease is expired, waits for period specified by the FencingGracePeriodMillis on the ClusterMBean, and then tries to invoke the Node Manager process on the machine that hosts the migratable server whose lease is expired, to restart the migratable server. ■ If unable to restart a migratable server whose lease has expired on its current machine, the cluster master selects a target machine in this fashion: ■ If you have configured a list of preferred destination machines for the migratable server, the cluster master chooses a machine on that list, in the order the machines are listed. ■ Otherwise, the cluster master chooses a machine on the list of those configured as available for hosting migratable servers in the cluster. A list of machines that can host migratable servers can be configured at two levels: for the cluster as a whole, and for an individual migratable server. You can define a machine list at both levels. You must define a machine list at least one level. ■ To accomplish the migration of a server instance to a new machine, the cluster master invokes the Node Manager process on the target machine to create a process for the server instance. The time required to perform the migration depends on the server configuration and startup time. 3-14 Oracle Fusion Middleware High Availability Guide ■ The maximum time taken for cluster master to restart the migratable server is HealthCheckPeriodsUntilFencing HealthCheckIntervalMillis + FencingGracePeriodMillis. ■ The total time before the server becomes available for client requests depends on the server startup time and the application deployment time.3.10 JMS and JTA High Availability
You can configure JMS and JTA services for high availability by using migratable targets. A migratable target is a special target that can migrate from one server in a cluster to another. As such, a migratable target provides a way to group migratable services that should move together. When the migratable target is migrated, all services hosted by that target are migrated. In order to configure a migratable JMS service for migration, it must be deployed to a migratable target. A migratable target specifies a set of servers that can host a target, and can optionally specify a user-preferred host for the services and an ordered list of candidate backup servers should the preferred server fail. Only one of these servers can host the migratable target at any one time. Once a service is configured to use a migratable target, then the service is independent from the server member that is currently hosting it. For example, if a JMS server with a deployed JMS queue is configured to use a migratable target, then the queue is independent of when a specific server member is available. In other words, the queue is always available when the migratable target is hosted by any server in the cluster. An administrator can manually migrate pinned migratable services from one server instance to another in the cluster, either in response to a server failure or as part of regularly scheduled maintenance. If you do not configure a migratable target in the cluster, migratable services can be migrated to any WebLogic Server instance in the cluster.3.10.1 User-Preferred Servers and Candidate Servers
When deploying a JMS service to the migratable target, you can select a the user-preferred server UPS target to host the service. When configuring a migratable target, you can also specify constrained candidate servers CCS that can potentially host the service should the user-preferred server fail. If the migratable target does not specify a constrained candidate server, the JMS server can be migrated to any available server in the cluster. WebLogic Server enables you to create separate migratable targets for JMS services. This allows you to always keep each service running on a different server in the cluster, if necessary. Conversely, you can configure the same selection of servers as the constrained candidate servers for both JTA and JMS, to ensure that the services remain co-located on the same server in the cluster.3.11 Administration Server and Node Manager High Availability
The Administration Server is the WebLogic Server instance that configures and manages the WebLogic Server instances in its domain. A domain can include multiple WebLogic Server clusters and non-clustered WebLogic Server instances. Strictly speaking, a domain could consist of only one WebLogic Server instance—however, in that case that sole server instance would be an Administration Server, because each domain must have exactly one Administration Server.Parts
» Oracle Fusion Middleware Online Documentation Library
» High Availability Problems High Availability Solutions
» High Availability Information in Other Documentation
» What Is the Administration Server? Understanding Managed Servers and Managed Server Clusters
» What Is a System Component Domain? What Is a Middleware Home? What Is a WebLogic Server Home?
» Oracle Fusion Middleware High Availability Terminology
» Server Load Balancing Oracle Fusion Middleware High Availability Technologies
» Local High Availability Active-Passive Deployment
» About Active-Active and Active-Passive Solutions
» Disaster Recovery Oracle Fusion Middleware High Availability Solutions
» Protection from Planned and Unplanned Down Time
» What Is a WebLogic Server Cluster? WebLogic Server Clusters and WebLogic Server Domains
» Application Failover Migration Key Capabilities of a Cluster
» Benefits of Clustering Types of Objects That Can Be Clustered
» Communications in a Cluster Cluster-Wide JNDI Naming Service
» Startup Process in a Cluster with Migratable Servers
» Administration Servers Role in Whole Server Migration Migratable Server Behavior in a Cluster
» Node Managers Role in Whole Server Migration Cluster Masters Role in Whole Server Migration
» Load Balancing Oracle Fusion Middleware Online Documentation Library
» Multi Data Sources Cluster Configuration and config.xml
» Java-Based Oracle Fusion Middleware Components Deployed to Oracle WebLogic Server
» Configuring Multi Data Sources for MDS Repositories
» Log on to SQLPlus as a system user, for example:
» Log on to SQLPlus as a user with sysdba privileges. For example:
» Configuring Multi Data Sources with Oracle RAC
» Oracle RAC Failover with WebLogic Server JDBC Clients
» Oracle Reports and Oracle Discoverer
» Troubleshooting Real Application Clusters
» SCAN Run Time Implications and Limitations
» Oracle SOA Service Infrastructure Protection from Failures and Expected Behavior
» Oracle SOA Service Infrastructure Cluster-Wide Configuration Changes
» Oracle BPEL Process Manager Request Flow and Recovery
» Oracle BPEL Process Manager Protection from Failures and Expected Behavior
» Oracle BPM Suite Component Characteristics
» Oracle BPM Suite Component Interaction
» Oracle BPMN Service Engine Single Instance Characteristics
» Oracle BPMN Service Engine High Availability Considerations
» Oracle Business Process Web Applications Single Instance Characteristics
» Oracle Business Process Analytics Single Instance Characteristics
» Oracle Mediator Component Characteristics Oracle Mediator Startup and Shutdown Lifecycle
» Oracle Mediator Request Flow
» Oracle Mediator Protection from Failures and Expected Behavior
» Troubleshooting Oracle Mediator High Availability
» Troubleshooting Oracle Human Workflow High Availability
» Oracle B2B Component Characteristics Oracle B2B Startup and Shutdown Lifecycle
» Oracle B2B Protection from Failures and Expected Behavior
» Oracle WSM Component Characteristics Oracle WSM Startup and Shutdown Lifecycle
» Oracle WSM Protection from Failures and Expected Behavior
» Oracle WSM Cluster-Wide Configuration Changes Configuring the Java Object Cache for Oracle WSM
» Configuring Distributed Notifications for the MDS Repository
» Oracle User Messaging Service Component Characteristics
» Oracle User Messaging Service Protection from Failures and Expected Behavior
» Oracle User Messaging Service Cluster-Wide Configuration Changes
» Oracle JCA Adapters Component Lifecycle
» Oracle JCA Adapters Reliability and Transactional Behavior
» Oracle JCA Adapters - Rejected Message Handling
» Oracle JCA Adapters High Availability Error Handling Oracle Database Adapters High Availability
» Oracle JMS Adapters High Availability
» Oracle JCA Adapters Log File Locations
» Oracle Business Activity Monitoring Component Characteristics
» Oracle Business Activity Monitoring Configuration Artifacts
» Oracle Business Activity Monitoring Protection from Failures and Expected Behavior
» Oracle Business Activity Monitoring Cluster-Wide Configuration Changes
» Oracle Service Bus Session State Oracle Service Bus External Dependencies
» Oracle Service Bus Configuration Artifacts Oracle Service Bus Deployment Artifacts
» Oracle Service Bus Protection from Failures and Expected Behavior
» Database Prerequisites VIP and IP Prerequisites Shared Storage Prerequisites
» Configuring Virtual Server Names and Ports for the Load Balancer
» Validating Oracle HTTP Server To verify that Oracle HTTP Server is set up
» Setting Connection Destination Identifiers for B2B Queues
» Starting Node Manager on SOAHOST2 Starting and Validating the WLS_SOA2 Managed Server
» Setting the Front End HTTP Host and Port
» Setting the WLS Cluster Address for Direct BindingRMI Invocations to Composites
» Deploying Applications Click Next.
» Configuring Server Migration for the WLS_SOA Servers
» Connect to the database as the leasing user. Run the leasing.ddl script in SQLPlus.
» Click Save. Oracle Fusion Middleware Online Documentation Library
» Enabling VIP1 and VIP3 in SOAHOST1 and VIP2 and VIP4 in SOAHOST2
» Configure Oracle Coherence for the Oracle Service Bus Result Cache
» Configuring a Default Persistent Store for Transaction Recovery Deploying Applications
» Configuring Server Migration for the WLS_OSB Servers
» Enabling VIP0 and VIP1 on BAMHOST1
» Oracle ADF Components Understanding Oracle ADF
» Oracle ADF Single Node Architecture Oracle ADF External Dependencies
» Oracle ADF Scope and Session State
» Oracle ADF Failover and Expected Behavior Oracle ADF Active Data Services
» Troubleshooting Oracle ADF Development Issues
» Deploying the ADF Application Validating Access through Oracle HTTP Server
» Select the Control tab. Select Environment Servers from the Administration Console. Select Clone.
» Oracle WebCenter Components Understanding Oracle WebCenter
» Oracle WebCenter Single-node Architecture Oracle WebCenter State and Configuration Persistence
» Oracle WebCenter External Dependencies
» Oracle WebCenter Configuration Considerations
» Oracle WebCenter Analytics Communications
» Oracle WebCenter State Replication Understanding the Distributed Java Object Cache
» Maintaining Configuration in a Clustered Environment
» Installing Oracle Fusion Middleware for Oracle WebCenter
» Enabling the Administration Server VIP
» Configuring a Virtual Host for Oracle Pagelet Producer and Sharepoint
» Configuring Activity Graph Click Start.
» Converting Discussions from Multicast to Unicast
» Configuring a Cluster for Oracle WebCenter Portal Applications
» Agent Startup and Shutdown Cycle Oracle Data Integrator External Dependencies
» Java EE Agent Configuration Standalone Agent Configuration
» Oracle Data Integrator Clustered Deployment
» WebLogic Server or Standalone Agent Crash Repository Database Failure
» About the 11g Oracle Identity Management Products
» Database Prerequisites Installing and Configuring the Database Repository
» Oracle Internet Directory Component Characteristics
» Oracle Internet Directory High Availability Architecture
» Protection from Failures and Expected Behavior
» Installing Oracle Fusion Middleware for Identity Management The next step is to
» Registering Oracle Internet Directory with a WebLogic Domain If you want to
» Creating boot.properties for the Administration Server on OIDHOST1 This section
» Configuring Oracle Internet Directory on OIDHOST2 Ensure that the Oracle Internet
» Validating Oracle Internet Directory High Availability
» Performing an Oracle Internet Directory Failover Performing an Oracle RAC Failover
» Troubleshooting Oracle Internet Directory High Availability
» Changing the Password of the ODS Schema Used by Oracle Internet Directory
» Oracle Virtual Directory Runtime Considerations Oracle Virtual Directory Component Characteristics
» Oracle Virtual Directory High Availability Architecture
» Configuring Oracle Virtual Directory on OVDHOST2 Follow these steps to configure
» Registering Oracle Virtual Directory with a WebLogic Domain It is recommended
» On the Installation Complete screen, click Finish to confirm your choice to exit.
» Troubleshooting LDAP Adapter Creation
» Oracle Directory Integration Platform Component Characteristics
» Oracle Directory Integration Platform High Availability Architecture
» Configuring Oracle HTTP Server for Oracle Directory Services Manager High
» If WebLogic Node Manager Fails to Start Operation Cannot Be Completed for Unknown Errors Message
» Oracle Directory Services Manager Component Characteristics
» Oracle Directory Services Manager High Availability Architecture
» Protection from Failures and Expected Behaviors
» Performing a WebLogic Server Instance Failover
» Using Oracle Directory Services Manager to Validate a Failover of a Managed Server
» Collocated Architecture Overview Troubleshooting Collocated Components Manager High Availability
» Additional Considerations for Collocated Components High Availability
» Oracle Access Manager Component Characteristics
» Oracle Access Manager High Availability Architecture
» Oracle Security Token Service High Availability Architecture
» Oracle Security Token Service Component Characteristics
» In the Customize Server and Cluster Configuration screen, select Yes, and click
» On the Configuration Summary screen, click Create to begin the creation process.
» Oracle Identity Manager Component Characteristics
» Runtime Processes Component and Process Lifecycle
» Starting and Stopping Oracle Identity Manager Configuration Artifacts External Dependencies
» Oracle Identity Manager High Availability Architecture
» On the Welcome screen, select Create a WebLogic Domain.
» Connect to the database as the leasing user.
» Select Environment - Servers from the Administration Console. Select Clone.
» Select the Automatic Server Migration Enabled option. This enables the Node Click Save.
» Click the OIMMSServerXXXXXX subdeployment. Add the new JMS Server
» Click Save. Authorization Policy Manager High Availability
» Oracle Adaptive Access Manager Component Characteristics
» Oracle Adaptive Access Manager High Availability Architecture
» On the Welcome screen, click Next.
» Oracle Identity Federation Component Characteristics
» High Availability Considerations for Integration with Oracle Access Manager
» Oracle Internet Directory Oracle Virtual Directory Oracle HTTP Server Node Manager
» WebLogic Administration Server Oracle Identity Manager
» Oracle Access Manager Managed Servers Oracle Adaptive Access Manager Managed Servers
» Oracle Identity Federation Starting and Stopping Oracle Identity Management Components
» Oracle HTTP Server and Oracle WebLogic Server
» Prerequisites Configuring Oracle HTTP Server for High Availability
» Install Oracle HTTP Server on WEBHOST2
» Oracle Web Cache Request Flow
» Oracle Web Cache Stateless Load Balancing
» Oracle Web Cache Backend Failover Oracle Web Cache Session Binding
» Oracle Web Cache Cluster-Wide Configuration Changes
» Oracle Web Cache as a Software Load Balancer
» From the Session Name list, select a session to enable binding for a specific
» Click Add. In the Component field, enter the name of the cache member.
» Adding a Node in Oracle Advanced Database Multimaster Replication
» Deleting a Node in Oracle Advanced Database Multimaster Replication
» Oracle IPM Component Characteristics
» Oracle IPM High Availability Architecture
» Creation of Oracle IPM Artifacts in a Cluster Troubleshooting Oracle IPM
» Oracle UCM Component Characteristics
» Oracle UCM High Availability Architecture
» Oracle UCM and Inbound Refinery High Availability Architecture
» Oracle URM High Availability Protection from Failure and Expected Behaviors
» Shared Storage Configuring the Oracle Database
» Installing Oracle ECM on ECMHOST1
» On the Welcome screen, select Create a new WebLogic domain.
» In the Select JMS Distributed Destination Type screen, select UDD from the
» Configuring Oracle HTTP Server on WEBHOST1
» Terminology for Directories and Directory Environment Variables
» Administration Server Topology 1 Transforming Oracle Fusion Middleware Infrastructure Components
» Administration Server Topology 2 Transforming Oracle Fusion Middleware Infrastructure Components
» Click Activate Changes. Choose Environment Servers. Click Control. Select WLS_EXMPL. Click Start.
» Transforming Oracle Internet Directory and Its Clients
» Select the Connect to a directory -- Create A New Connection link in the
» Click JDBC Connection under Data Sources.
» Click Administration. Click Scheduler Configuration under System Maintenance Click Apply.
» Database Instance Platform-Specific Considerations
» Example Topology 1 Example Topology 2
» Destination Topologies Cold Failover Cluster Transformation Procedure
» Introduction to Oracle Clusterware Cluster Ready Services and Oracle Fusion Middleware
» Upgrading Older Versions of ASCRS to the Current ASCRS Version Installing ASCRS
» Configuring ASCRS with Oracle Fusion Middleware
» Creating a Virtual IP Resource Creating a Shared Disk Resource
» Creating an Oracle Database Listener Resource Creating an Oracle Database Resource
» Creating a Middleware Resource
» Updating Resources Starting Up Resources Shutting Down Resources Resource Switchover
» Oracle Portal, Forms, Reports, and Discoverer Architecture
» Oracle Forms Runtime Considerations Oracle Forms Process Flow
» Oracle Forms Configuration Files Oracle Forms External Dependencies Oracle Forms Log Files
» Oracle Discoverer Runtime Considerations
» Preference Server Failover Session State Replication and Failover Performance Recommendation
» Dependencies Network Requirements Prerequisites
» Install Oracle WebLogic Server Install Oracle Portal, Forms, Reports, and Discoverer Validation
» Oracle BI EE Component Characteristics
» Oracle BI EE and EPM High Availability Architecture
» Shared Files and Directories
» Cluster-Wide Configuration Changes Oracle BI EE High Availability Concepts
» Oracle Essbase Component Characteristics
» Oracle Essbase High Availability Architecture Protection from Failures and Expected Behaviors
» Oracle Hyperion Provider Services Component Characteristics
» Oracle Hyperion Provider Services High Availability Architecture
» Workspace Component Characteristics Oracle EPM Workspace Component Architecture
» Workspace High Availability Architecture
» Oracle Hyperion Financial Reporting Component Characteristics
» Oracle BI Publisher Component Characteristics
» Oracle BI Publisher High Availability Architecture
» Oracle RTD Component Characteristics
» Oracle RTD High Availability Architecture
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