The major components of the WebLogic JMS Server architecture, as illustrated in the figure below.

* (A) JMS servers that can host a defined set of modules and any associated persistent storage that reside on a WebLogic Server instance.

* (B) JMS modules contains configuration resources (such as queues, topics, and connections factories) and are defined by XML documents that conform to the weblogic-jmsmd.xsd schema.

* Client JMS applications that either produce messages to destinations or consume messages from destinations.

* JNDI (Java Naming and Directory Interface), which provides a resource lookup facility. JMS resources such as connection factories and destinations are configured with a JNDI name. The runtime implementations of these resources are then bound into JNDI using the given names.

* (E) WebLogic persistent storage (file store or JDBC-accessible) for storing persistent message data.

The following figure illustrates the WebLogic JMS architecture.

C: The saviour of having to type in the username and password each and every time that you start a server. A very useful little file to have, particularly if you have multiple managed servers.

By default, this appears in the Admin Servers security directory ($DOMAIN_HOME/servers/AdminServer/security) when a domain is created in development mode and is called boot.properties. The file is only created for the admin server, not for any additional servers; simply copying the security directory over is enough. The password is encrypted for the domain, so it can only be used for servers within that domain.

In production mode, the boot.properties file doesn't exist.

D: Development mode enables a WebLogic Server instance to automatically deploy and update applications that are in the domain_name/autodeploy directory (where domain_name is the name of a WebLogic Server domain). Production mode disables the auto-deployment feature and prevents any applications you place in the autodeploy directory after you switch to production mode from being deployed.

Note:

* By default, a WebLogic Server domain runs in development mode.

* You can run a WebLogic Server domain in two different modes: development and production. Only development mode allows you use the auto-deployment feature

Note:

* A multi data source can be thought of as a pool of data sources. Multi data sources are best used for failover or load balancing between nodes of a highly available database system, such as redundant databases or Oracle Real Application Clusters (Oracle RAC).

* (not B) A single GridLink data source provides connectivity between WebLogic Server and an Oracle Database service, which may include multiple Oracle RAC clusters

* High Availability Storage Solutions

If you have applications that need access to persistent stores that reside on remote machines after the migration of a JMS server or JTA transaction log, then you should implement one of the following highly-available storage solutions:

/ File-based stores (default or custom)---Implement a hardware solution, such as a dual-ported SCSI disk or Storage Area Network (SAN) to make a file store available from shareable disks or remote machines.

/ JDBC-accessible stores---Configure a JDBC store or JDBC TLOG store and use JDBC to access this store, which can be on yet another server. Applications can then take advantage of any high-availability or failover solutions offered by your database vendor. In addition, JDBC stores support GridLink data sources and multi data sources, which provide failover between nodes of a highly available database system, such as Oracle Real Application Clusters (Oracle RAC).

Note:

* It is recommended that you shutdown WebLogic Server instances through the Administration Console.

* If automatic server migration is enabled, the servers are required to contact the cluster leader and renew their leases periodically. Servers will shut themselves down if they are unable to renew their leases. The failed servers will then be automatically migrated to the machines in the majority partition.

* When you create a data source using the Administration Console, the Administration Console automatically sets the Test Table Name attribute for a data source based on the DBMS that you select. The Test Table Name attribute is used in connection testing which is optionally performed periodically or when you create or reserve a connection, depending on how you configure the testing options. For database tests to succeed, the database user used to create database connections in the data source must have access to the database table. If not, you should either grant access to the user (make this change in the DBMS) or change the Test Table Name attribute to the name of a table to which the user does have access (make this change in the WebLogic Server Administration Console).

* To manually test a connection from a data source, you can use the Test Data Source feature on the JDBC Data Source: Monitoring: Testing page in the Administration Console (see '' Test JDBC data sources'') or the testPool() method in the JDBCDataSourceRuntimMBean. To test a database connection from a data source, Test Reserved Connections must be enabled and Test Table Name must be defined in the data source configuration. Both are defined by default if you create the data source using the Administration Console.

When you test a data source, WebLogic Server reserves a connection, tests it using the query defined in Test Table Name, and then releases the connection.