What is Weblogic?
WebLogic is a J2EE application server and also an HTTP web server by Oracle, for UNIX, Linux, Microsoft Windows, and other platforms. WebLogic supports Oracle, DB2, Microsoft SQL Server, and other JDBC-compliant databases.
What is the name of the default JVM that is used for WebLogic?
The sun hotspot JDK default is used for development, and JRockit is the one used for the production of WebLogic 11g as well as 12c. The operating system is another factor that helps in choosing the certified JDK JVM.
We often see BSU when using Weblogic. What is the meaning of BSU?
Oracle bought Weblogic from BEA. BSU Stands for Bea Smart Update. This utility is used to apply the WebLogic Server Patches. In simple terms, it is the first letter of the name of founders Bill Coleman, Ed Scott, and Alfred Chuang.
What are the Basic Components of Weblogic Server?
These are the basic WebLogic components
1)Domains
2)Admin Server
3) Managed Server
4) Node Manager
5) Weblogic Server Cluster
Explain the methods for providing user credentials for starting the server.
At the time of the creation of the domain, the wizard for setting configuration asks for details like user name, password, etc. from the user who is logging in for the first time as an administrator. If the domain is created in development mode, the configuration wizard saves the encrypted password as well as the username inside an identity file. This file is available for reference during the time of booting so that in the absence of this file, the system can prompt the user to enter credentials. A new boot–identity file can be created if you want to change the use credentials or else if you have the requirement of creating a domain in the production mode.
What are the Basic Components of a Weblogic Server?
These are the basic WebLogic components
1)Domains
2)Admin Server
3) Managed Server
4) Node Manager
5) Weblogic Server Cluster
Explain the methods for providing user credentials for starting the server.
At the time of the creation of the domain, the wizard for setting configuration asks for details like user name, password, etc. from the user who is logging in for the first time as an administrator. If the domain is created in development mode, the configuration wizard saves the encrypted password as well as the username inside an identity file. This file is available for reference during the time of booting so that in the absence of this file, the system can prompt the user to enter credentials. A new boot–identity file can be created if you want to change the use credentials or else if you have the requirement of creating a domain in the production mode.
What is the Admin Server?
Admin Server is the central domain configuration interface that is used to create, delete, and
configure the resources of a domain like managed server, machine, cluster, data source, work managers, etc.
What are the capabilities of the WebLogic server?
There are various capabilities associated with the WebLogic server and they are
Changes in dynamic configuration.
Production application redeployment.
Rolling upgrades.
How Administration server and Managed servers will interact?
The Administration Server stores the master copy of the domain configuration, including the
configuration for all Managed Servers in the domain. Each Managed Server stores a local copy of the domain configuration file. When a Managed Server starts, it connects to the administration Server to synchronize the configuration. When the configuration is changed, the Administration Server sends the changed configuration to the Managed Servers.
Why node manager is required?
A Node Manager process is not associated with a specific WebLogic domain but with a machine. You can use the same Node Manager process to control server instances in any WebLogic Server domain, as long as the server instances reside on the same machine as the Node Manager process. Node Manager must run on each computer that hosts WebLogic Server instances. Whether an Administration Server or a Managed Server that you want to control with Node Manager.
| Learn more information from the GoLogica “Weblogic Admin Training“ |
How do stubs function inside the WebLogic server cluster at the time of failure?
Stubs perform the process of removing the failed instance from the list whenever there is a failure. The stub usually makes use of DNS for finding the running server and also for obtaining the list of the instances that are currently available with the application. The list of the instances available with the server inside the cluster gets periodically refreshed and allows for acquiring advantages associated with new servers. The advantages are gained as the server gets added to the cluster.
How many types of WebLogic installations?
There are 3 types of weblogic installation.
(a) Graphical Mode (interactive GUI-based)
(b) Console Mode (interactive Text Based)
(c) Silent Mode (Non-Interactive method using .xml properties file)
How do clients handle the DNS – requests to the failed servers?
Bandwidth gets wasted in the case of continuous DNS requests to that of an unavailable machine at the time of server failure. This problem usually occurs during the time of startup associated with the application of the client side. The unavailable servers are removed by searching DNS entries provided by the WebLogic server. This removal prevents the clients from accessing failed servers. Third-party load – -balancers are used to avoid unnecessary DNS requests. Some of the third-party load–balancers are BigIP, resonate, local director, and Alteon. The main function of these third-party load–balancers is to mask multiple addresses of DNS into a single one.
What is the difference between the Sun JVM and BEA JRockit JVM?
The most well-known JVM is the implementation from Sun. The Sun JVM is called HotSpot. The Sun JVM is shipped in the Java Developer’s Kit (JDK) and Java Runtime Environment (JRE) from Sun.
The BEA JRockit JVM from BEA systems is optimized for reliability and performance for server-side applications. To achieve this, BEA JRockit JVM uses technologies such as code generation, hot spot detection, code optimization, advanced garbage collection algorithms, and tight operating system integration.
Explain the functioning of Stub.
A stub is usually expected by the people who connect to the WebLogic server cluster. The stub has a list that consists of the available instances of servers that perform host implementations associated with an object. The stub also has the functionality of balancing the load by distributing the load amongst the host servers.
What are the steps for the creation of Pooling within the Tomcat server?
The first step involved in this process of creating pooling is to download 3 jar files which are the commons-dbcp-1.2 jar, commons-pool-1.3.jar, and commons-collections-3.1 jar.
The next step is to make an entry inside server.xml of the tomcat factory.
What is the default port of the Weblogic admin server?
By default weblogic admin server is configured on port 7001 and SSL is on 7002.
How can Server Hang be solved?
Java WebLogic.Admin PING needs to be checked to find whether you get a normal and positive response. You can find out the root cause for hanging from this file. You just need to rectify the errors that are identified in this file.
What is the advantage of clustering?
WebLogic clustering offers three important benefits:
1. Scalability:
The capacity of an application deployed on a WebLogic Server cluster can be increased dynamically to meet demand. You can add server instances to a cluster without interruption of service — the application continues to run without impact on clients and end users.
2. Load balancing:
The ability to distribute requests across all members of the cluster, according to the workload on each server.
3. High availability:
A mix of features that ensure applications and services are available even if a server or machine fails. Clients can continue to work with little or no disruption in a highly available environment. WebLogic achieves high availability using a combination of features: replication, failover, and migratable services.
👉 Related Article:
🎯 Oracle WebLogic Server JMS Administration Interview Questions