September 5, 2017

Srikaanth Kumar

Weblogic Experienced Interview Questions Answers


Explain the concepts and capabilities of Web Logic Server.

Web Logic server supports the services and infrastructure for JEE applications. The deployment of java applications and components as services through SOAP, UDDI and WSDL, is performed by Web Logic server. The server can be configured as a web server by using its own HTTP listener that supports HTTP 1.1. The web servers of Apache, Microsoft IIS and Netscape can also be utilized. The web server configuration allows the Web Logic server to provide services to the static and dynamic requests that are generated by HTML, Servlets and JSP.
The following are some of the capabilities of Web Logic server:

1. Dynamic configuration changes

2. Production application redeployment

3. Rolling upgrades

These capabilities help the availability of running systems, while changes are making.

What is the function of T3 in WebLogic Server?

The enhancements support for WebLogic Server messages is provided by T3. These enhancements include object replacement, which work in WebLogic Server clusters’ context and HTTP. Java Object Serialization, RMI predation is done by T3. T3 is superset of java Object. Serialization and RMI can be done over T3.

Between WebLogic Servers, and between programmatic clients & a WebLogic Server cluster, T3 is mandated. To communicate between processes and WebLogic Server, the protocols HTTP and IIOP can be used and optional. The HTTP is used to communicate between a browser and WebLogic Server. The IIOP is used to communicate between an Object Request Broker and WebLogic Server.

How do stubs work in a WebLogic Server cluster?

The enhancements support for WebLogic Server messages is provided by T3. These enhancements include object replacement, which work in WebLogic Server clusters’ context and HTTP. Java Object Serialization, RMI predation is done by T3. T3 is superset of java Object. Serialization and RMI can be done over T3.

Between WebLogic Servers, and between programmatic clients & a WebLogic Server cluster, T3 is mandated. To communicate between processes and WebLogic Server, the protocols HTTP and IIOP can be used and optional. The HTTP is used to communicate between a browser and WebLogic Server. The IIOP is used to communicate between an Object Request Broker and WebLogic Server.

What happens when a failure occurs and the stub cannot connect to a WebLogic Server instance?

The stub removes the instance that is failed from its list, when a failure occurs. The stub uses DNS again for the purpose of finding a running server and obtains a current list of instances, when there are no servers left in its list. The list of available server instances in the cluster will get periodical refreshment, which allows making the advantage of new servers. This is because; the servers are added to the cluster.

How do clients handle DNS requests to failed servers?

The bandwidth will be wasted if the DNS continually sends requests to the unavailable machine, when the server is failed so. This problem occurs only during start up, for a client application. The unavailable servers are removed by searching the DNS entries by a WebLogic server. This prevents the accessibility of a client to a failed server.

To avoid the DNS requests those are unnecessary, with the browser-based clients, a third-party load-balancers are used. These are Resonate, BigIP, Alteon, and Local Director. The masking of multiple DNS addresses into a single address is done by these third-party load-balancers.

Explain how to create Pooling in tomcat?

The following are the steps to create Pooling in tomcat:

Download 3 jar files
commons-dbcp-1.2.jar
commons-collectons-3.1.jar
commons-pool-1.3.jar
Add an entry in server.xml of the tomcat factory
org.apache.commons.dbcp.BasicDataSourceFactory driverClassName oracle.jdbc.OracleDriver url jdbc:oracle:thin:@localhost:1521:orcl username visisht password vst2wrd maxActive 20 maxIdle 10 maxWait -1
*** visisht is the user name and vst2wrd is the password

What is the difference between weblogic and websphere?

Though the functionality of these two products are closer, there are minor differences in the standards that support. These differences are:

1. WebSphere’s focus is more on connectivity, integration and web services where as WebLogic’s focus is more on emerging standards and ease-of-use of J2EE.

2. WebSphere’s performance is better in terms of implementations of J2EE is little more involved, and supports more integration and transaction management to a great extent.

3. WebLogic is supported by default transaction attribute – “Supports”, where as WebSphere has not default transaction attribute.

4. WebSphere strictly follows J2EE architecture.



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