BEA WebLogic 8.1 Certified Administrator (3)

Manage Quality of Service

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• Http session state clustering and object clustering are the two primary cluster services that Weblogic server provides.
• Data Source objects can be defined with or without JTA, which provides support for distributed TX.

Troubleshoot and Diagnose Error Conditions

• To test two-tier and three-tier JDBC database connections after installing weblogic Server use the utils.dbping utility.
• A cluster is part of a particular WLS domain. You can’t split cluster in multiple domains.

Other

• Before Completion Interation Limit is a TX setting which gives the number of beforeCompleption callbacks that are processed before the system forces a rollback.
• Forget Heuristic is a Boolean value specifying whether the transaction manager should instruct a resource to forget any TX with a euristic outcome.
• A connection object represents an open communication channel between an application and the messaging system. Connection objects are used to create a session for producing and consuming messages. A connectionFactory object encapsulates connection information and enables JMS applications to create a connection. The session object, defines the serial order for the messages produced and consumed. By default a connection is created in stopped mode.
• You can create destination keys to define the sort order for messages arriving on a specific JMS destination (queue or topic).

  1. name of the destination key

  2. message sort key name or the name of a message header field on which to sort. Message header field keys start with the letters JMS and ignore the key type setting. (For better performance, use message header fields as sorting keys, rather than message properties.)

  3. The expected property type for the sort key. (This setting is ignored for message header field keys, which have an implied type.)

  4. The direction in which the key will sort messages (ascending or descending).

• WLS model of centralizing management responsibilities on the Administration Server, Administration Server hosts Configuration Mbeans for all managed resources on all server istances in the domain.
• WLS Mbeans that expose attributes and operations for configuration a managed resource are called Configuration Mbeans while Mbeans that provide information about the runtime state of a managed resource are called Runtime Mbeans.
• JDBC Multipools provide backup pools and load balancing to enhance database connectivity. Multipools don not apply to multiple-server configurations, so they are not supported in distributed TX. Multipools allow a configurable algorithm for choosing a connection pool from its list of pools. The connection pools whin a Multipools may be associated with different DBMS.
• All WLS resources are managed through this JMX based service.
• The EJB container blocks the concurrent method call and allows it to proceed when the perious call has completed if the value of allow-concurrent-calls is true. The concurrency-strategy element determines ejbLoad and ejbStore behavior for entity EJB instances.
• Check testConnsOnReserve , and testConnsOnRelease