Interview Questions.

Q1. What Is Weblogic?

Ans: WebLogic is a J2EE application server and additionally an HTTP internet server with the aid of Oracle , for Unix, Linux, Microsoft Windows, and other systems. WebLogic supports Oracle, DB2, Microsoft SQL Server, and different JDBC-compliant databases.

Q2. What is domain in WebLogic ?

Ans: Domain is a group of WebLogic server sources like admin server, controlled server, jms,connection pool, statistics resources and so on or whatever the resource you realize of WebLogic server.  Seeing that area is the fundamental unit you have to create after installation and the entirety created and configured under a site.

There can simplest be one management Server in domain and 0 to N Managed Server.

Q3. What are the Basic Components Of Weblogic Server?

Ans: These are the basic weblogic additives

Domains

Admin Server

Managed Server

Node Manager

Weblogic Server Cluster

Q4. What Is The Server

Ans: A server is an example of weblogic.Server executing in a Java Virtual Machine (JVM).

A server:

Runs on a chosen Oracle WebLogic Server device

Has a devoted amount of RAM

Is multithreaded

Two types of servers:

 Administration Server

Managed Server

Q5. What is Administration Server ?

Ans: Admin server is the important point from where you may configure, Monitor and manage all  sources of a website.Administration Server is WebLogic Server instance that keeps configuration records for a  area. You can set up your software on management Server however it's far encouraged to  create managed Server and installation your software in managed server and go away  Administration domain for configuration and maintenance.There will always be at the least one Administration Server in a domain.

Q6. What Is The Managed Server?

Ans: Managed server is a server in a website that isn't always the Administration server. It contacts the administration server for configuration records. It runs enterprise software in a production surroundings. It is independent of all different Managed servers in a site (until they may be not in a cluster). You could have many managed servers in a domain. Individual managed servers are normally delivered for capability and application isolation.

Q7. How Many Types You Configure Managed Server In Weblogic Server?

Ans: Three sorts

1.Domain Configuration Wizard

2.Administration Console

three.Weblogic Scripting Tool

Q8. What Is Node Manager?

Ans: Node Manager is program that is used to manipulate WebLogic Server instances. A single Node Manager example is used to govern all the server instances going for walks on the identical bodily device or specific system.  These times can are living in special clusters, domain names, and such. You ought to configure every device for your area to communicate with Node Manager.

Q9. How Administration Server And Managed Servers Will Interact?

Ans: The Administration Server shops the master copy of the area configuration, which include the configuration for all Managed Servers within the domain. Each Managed Server shops a local replica of the domain configuration report. When a Managed Server starts, it connects to the Administration Server to synchronize the configuration. When the configuration is modified, the Administration Server sends the modified configuration to the Managed Servers.

Q10. What Are The Supported Installation Modes For Weblogic Server

Ans:

Graphical mode

console mode

silent mode

Q11. What Is The Default Port Of Weblogic Admin Server?

Ans: By default weblogic admin server configured on port 7001 and SSL is on 7002.

Q12. What Is Boot.Proerties File In Weblogic Server?

Ans: boot.Houses is the report used by admin or managed server at some point of startup for username and password. It exist underneath your domain/servers/server_name/security folder.

Q13. What Is Config.Xml?

Ans: Config.Xml is the imperative configuration repository for a website. Each aid you have configured from admin console or by way of command line or with the aid of another device registered beneath this report.WLS 9.X onwards, this report include references to different xml configuration documents additionally the ones are beneath your domain/config folder ( similarly sub folder beneath it for respective sources ).

Q14. Difference Between Weblogic Development And Production Mode?

Ans: Difference among Weblogic Development Mode and Production Mode:

Development Mode:

The default JDK for improvement area is Sun Hotspot

You can use the demo certificates for SSL

Auto deployment is enabled

Server times rotate their log documents on startup

Admin Server makes use of an routinely created boot.Residences for the duration of startup

The default maximum potential for JDBC Datasource is 15
 

Production Mode:

The default JDK for manufacturing area is JRockit

If you operate the demo certificates for SSL a warning is displayed

Auto deployment is disabled

Server instances rotate their log files while it reaches 5MB

Admin Server activates for username and password during startup

The default most capability for JDBC Datasource is 25

HubSpot Video
 

Q15. How Do I Provide User Credentials For Starting Weblogic Server?

Ans: When you create a site, the Configuration Wizard activates you to offer the username and password for an initial administrative person. If you create the area in development mode, the wizard saves the username and encrypted password in a boot identity file.

A WebLogic Server example can confer with a boot identification document all through its startup technique. If a server instance does no longer discover any such document,it prompts you to go into credentials.

If you create a site in manufacturing mode, or in case you need to change person credentials in an existing boot identification record, you could create a brand new boot identity report.

Q16. Can We Start A Managed Server If The Administration Server Is Unavailable?

Ans: By default, if a Managed Server is not able to connect with the specified Administration Server throughout startup, it is able to retrieve its configuration through reading a configuration report and other documents directly. You can't alternate the server’s configuration till the Administration Server is to be had. A Managed Server that starts offevolved on this way is walking in Managed Server Independence mode.

Q17. What Is A Weblogic Server Cluster?

Ans: A WebLogic Server cluster consists of a couple of WebLogic Server server instances jogging simultaneously and working collectively to offer multiplied scalability and reliability.

A cluster appears to clients to be a unmarried WebLogic Server example. The server instances that represent a cluster can run at the equal system, or be positioned on specific machines.

You can growth a cluster’s ability with the aid of adding extra server times to the cluster on an present machine, or you may upload machines to the cluster to host the incremental server times.

Each server example in a cluster need to run the same model of WebLogic Server.

Q18. How To Change From Development Mode To Production Mode In Weblogic 10.Three?

Ans: To alternate Weblogic start up mode from DEV to production. One way to change it's miles, by honestly modifying setDomainEnv.Cmd which resides in $root_domain/bin folder.

1. Look for the road that sets the PRODUCTION_MODE script variable: set PRODUCTION_MODE

Add false to the fee of the PRODUCTION_MODE variable to ensure the server starts in development

Set proper for beginning in prod mode.

Set PRODUCTION_MODE=false

2. Save your adjustments and go out the text editor

Q19. What Is The Advantage Of Clustering?

Ans: WebLogic clustering gives three essential blessings:

 Scalability :  The potential of an software deployed on a WebLogic Server cluster may be improved dynamically to fulfill demand. You can upload server instances to a cluster with out interruption of provider — the software continues to run with out impact to clients and quit customers.

Load balancing : The potential to distribute requests across all participants of the cluster, in accordance tothe workload on each server.

 High availability : A mix of capabilities that make sure packages and offerings are available even supposing aserver or system fails.Clients can continue to work with very little disruption ina surprisingly available environment. WebLogic achieves high availability using acombination of features: replication, failover, and migratable services.

Q20. What Is Ssl In Weblogic?

Ans: Secure Sockets Layer (SSL) offers at ease connections via permitting two packages connecting over a network connection to authenticate the opposite's identification and by encrypting the facts exchanged between the programs. Authentication allows a server and optionally a client to verify the identification of the software on the opposite cease of a network connection. Encryption makes records transmitted over the community intelligible handiest to the intended recipient

Q21. How Does A Cluster Relate To A Domain?

Ans: A cluster is part of a particular WebLogic Server area.A domain is an interrelated set of  WebLogic Server assets which might be controlled as a unit. A area includes one or greater WebLogic Server instances, which can be clustered, non-clustered, or a combination of clustered and non-clustered times. A area can encompass more than one clusters. A area additionally consists of the utility additives deployed within the domain, and the sources and services required through the ones application components and the server instances in the domain.

Q22. How To Know Weblogic Version?

Ans: In the WebLogic console, in the left navigation tree, click on "Environment", then "Servers". Then click on one of the servers inside the list. Then click at the "Monitoring" tab. Look on the "WebLogic Version" discipline.

Q23. What Is Multicast And Unicast In Weblogic?

Ans: Mulicast : Multicast is easier to explain over Unicast. Multicast is a published UDP option for sending a packet/announcement over to a set this is listening on a specific multicast cope with and port over which the declaration is despatched.There is a defined range for legitimate Multicast cope with (224.Zero.Zero.1 to 239.255.255.255). Everyone listening at the given deal with hears the statement similar to following a Twitter put up. Some barriers with Multicast is the TTL (time to live) across machines/subnets/routers desires to be adjusted and the routers configured to retransmit the multicast packet throughout subnet.

Unicast : Unicast is more of a factor to point UDP choice to ship the packet to a selected member and no longer anyone. That manner, unicast is more of a private communique among  people while multicast is more of a shout to a group or room. Both are UDP based totally, so there may be losses unlike TCP that handles retransmissions on message loss. But Unicast can span throughout routers and does no longer have to fear approximately TTL with out the everyone hearing the declaration. So, Network Admins in general opt to go together with Unicast over Multicast for those motives

Q24. What Is Horizontal And Vertical Clustering?

Ans: There are two approach of clustering Horizontal and Vertical.

Horizontal clustering : includes going for walks more than one Java utility servers which are run on two or extra separate bodily machines.Horizontal scaling is more reliable than vertical scaling, because there are multiple machines worried inside the cluster surroundings, as compared to only one device

Vertical clustering: however, consists of a couple of Java software servers on a unmarried bodily system.With vertical scaling, the system's processing energy, CPU utilization, and JVM heap memory configurations are the main factors in figuring out what number of server instances have to be run on one system.

Q25. How Do You Set The Classpath?

Ans: WebLogic Server installs the subsequent script that you can use to set the classpath that a server requires:

WL_HOMEserverbinsetWLSEnv.Cmd (on Windows)

WL_HOME/server/bin/setWLSEnv.Sh (on UNIX)

Q26. What Is The Msi Mode In Weblogic? How Can You Enable And Disable This Option?

Ans: MSI is not anything but Managed Server Independence. By default, Managed Servers can function independently of the Administration Server. A Managed Server example can start in MSI mode if the Administration Server is unavailable. Configure MSI mode from the Administration Console.To start a Managed Server in MSI mode, perform the following:

Ensure that the Managed Server’s root directory carries the config subdirectory. If the config subdirectory does no longer exist, reproduction it from the Administration Server’s root listing.Start the Managed Server on the command line or through using a script.

Environment > Servers > Server_Name > Tuning > Advanced > Managed Server Independence Enabled take a look at container

Q27. How Many Way To Start And Stop Weblogic Servers?

Ans: There are many ways to begin & stop weblogic Admin and controlled servers:

You can start and prevent Admin Server the use of :

1) Script

2) "Java weblogic.Server "command(The weblogic.Server elegance is the principle class for a WebLogic Server instance)

3) From startup option on windows

four) WLST with or without node manager

You can begin managed servers the use of :

1) scripts

2) admin console

three) using WLST

four) the use of node manager

five) java weblogic.Server command( The weblogic.Server magnificence is the main magnificence for a WebLogic Server example )

Q28. How Does A Server Know When Another Server Is Unavailable?

Ans: WebLogic Server makes use of two mechanisms to determine if a given server instance is unavailable. Each WebLogic Server example in a cluster makes use of multicast to broadcast normal “heartbeat” messages that put it on the market its availability. By monitoring heartbeat messages, server times in a cluster determine when a server instance has failed. The different server instances will drop a server instance from the cluster, in the event that they do now not acquire three consecutive heartbeats from that server example WebLogic Server also monitors socket errors to determine the supply of a server instance. For instance, if server instance A has an open socket to server example B, and the socket unexpectedly closes, server A assumes that server B is offline

Q29. How Do You Differentiate Between A Server Hang And Server Crash Issue?

Ans: When a Server crashes, the JAVA method not exists. When the Server is hung, it stops responding.We can use the WebLogic .ADMIN utility to ping the server. In case of a hold scenario we can take a couple of thread dumps and analyze the purpose of han

Q30. How Are Notifications Made When A Server Is Added To A Cluster?

Ans: The WebLogic Server cluster publicizes the supply of a brand new server example whenever a brand new instance joins the cluster. Cluster-aware stubs additionally periodically update their list of available server instances.

Q31. How Do I Turn The Auto-deployment Feature Off?

Ans: The car-deployment feature checks the packages folder each three seconds to decide whether there are any new applications or any changes to current packages and then dynamically deploys these changes.

The vehicle-deployment feature is enabled for servers that run in development mode.

To disable auto-deployment characteristic, use one of the following methods to place servers in manufacturing mode:

=>In the Administration Console, click the name of the area inside the left pane, then pick the Production Mode checkbox within the right pane.

=>At the command line, encompass the following argument when beginning the domain’s Administration Server:

-Dweblogic.ProductionModeEnabled=actual

Production mode is about for all WebLogic Server times in a given domain.

Q32. How Managed Servers Communicate With Each Other?

Ans: Managed servers communicate each other the use of t3 protocol internally.

Q33. What Is A Thread Dump? How Will You Take In Unix/linux And Windows?

Ans: A Java thread unload is a way of finding out what every thread in the JVM is doing at a specific factor in time. This is particularly useful if your Java software now and again appears to hang when running below load, as an analysis of the unload will display where the threads are caught.

1) Linux : kill -3 <ps_id>

2) Windows (console mode) : crtl+spoil

3) Windows (carrier) : beasvc -unload -svcname:mydomain_myserver

Q34. Explain Deployment Descriptors?

Ans: Deployment descriptors are associated with nearly all of the modules in addition to packages. The deployment descriptors may be seen inside the form of XML documents and they may be capable of describing the contents which might be a part of directory or the jar document. J2EE specifications normally outline the usual in addition to the deployment descriptors which are transportable for J2EE applications and modules.

Q35. What Is Core Server Tuning?

Ans: This is the technique involving the tuning of labor manager, chuck size, overall performance packs, bite pool size and connection backlog buffering.

Q36. How Many Weblogic Servers Can Be Held Inside A Multi-processor Machine?

Ans: There is no predicament for the number of servers

Q37. What Is A Stage Deployment?

Ans: Stage deployment is a sort of method in which the admin receives a physical replica which is shipped to the opposite times.

Q38. What Is The Name Of Default Jvm That Is Made Used For Weblogic?

Ans: The solar hotspot JDK default is made used for development, JRockit is the one used for manufacturing of WebLogic 11g in addition to 12c. Operating gadget is every other issue that enables in deciding on the certified JDK JVM.

Q39. Explain The Methods For Providing User Credentials For Starting The Server?

Ans: At the time of the advent of domain, the wizard for setting configuration asks for the details like consumer name, password etc. From the user who's logging in for the primary time as an administrator. If the area is created in development mode, the configuration wizard saves the encrypted password in addition to the username interior an identification record. This file is available for reference all through the time of booting in order that in the absence of this document, device can set off the user for the motive of getting into credentials. A new boot – identification record may be created if you need to change the use credentials otherwise in case you are having the requirement of creating area inside the production mode.

Q40. Is There Any Possibility For Starting Managed Server During The Absence Of Administrator Server?

Ans: The normal manner is that in case of any issue for the manager server to get connected to any management server on the time of begin up, there may be an option for the controlled server to retrieve the configuration associated with it from the configuration documents as well as other documents worried. The statistics for this reason retrieved can't be altered and it's far viable only while the administration server is sincerely to be had. When the management server is unavailable, then the controlled server enters into its independence mode for sporting out its operations.

Q41. How You Deploy Your Applications On Weblogic Server?

Ans: These are the kinds.

Auto Deployment

Console

Command line – weblogic.Deployer

ANT / WLST

Q42. What Are Stating Modes Are Available In Weblogic Server ?

Ans: There are three starting modes are available:

Stage mode : Administration Server copies the deployment documents from their unique vicinity on the Administration Server system to the staging directories of every target server

External Stage : target servers deploy the use of local copies of the deployment documents, here the Administration Server does now not routinely reproduction the deployment files to focused servers in external_stage mode ; alternatively, you must reproduction the documents to the staging listing of each target server before deployment.

No Stage : The Administration Server does now not copy deployment unit documents; as an alternative, all servers install the usage of the same bodily copy of the deployment documents, which must be directly accessible via the Administration Server and goal servers

Q43. What Is The Purpose Of Clustering?

Ans: The fundamental goal of performing the procedure of clustering is to make excessive scalability in addition to availability of the servers possible. This system also allows in balancing the burden in a right manner and additionally accomplishes failover.

Q44. How Can Cluster Communication Occur?

Ans: The conversation through cluster is made feasible through the multicast IP in addition to port by using the system of sending periodic messages which might be generally referred to as as heartbeat messages.

Q45. How Do Stubs Function Inside Weblogic Server Cluster At The Time Of Failure?

Ans: Stubs perform the method of disposing of the failed example from the list whenever there's a failure. The stub usually uses DNS for finding the running server and also for acquiring the listing of the instances which can be currently to be had with the software. List of the instances to be had with the server internal cluster gets periodically refreshment and permits in acquiring blessings related to new servers. The benefits are gained because the server gets added to the cluster.

Q46. What Are The Capabilities Of Weblogic Server?

Ans: There are diverse abilties related to WebLogic server and they may be

Changes in dynamic configuration

Production utility redeployment

Rolling upgrades

Q47. What Is Non-degree Deployment?

Ans: There isn't any reproduction inside the administrator however every and every server desires to contact the source immediately for purchasing the object to be deployed.

Q48. How Can Port Number Be Checked?

Ans: Port variety can be checked through the use of netstat-narelated

Q49. What Are The Various Types Of Weblogic Installations?

Ans: The WebLogic installation usually takes place in three distinct modes that are:

Graphical mode

Console mode

Silent mode.

Q50. Explain The Term Clustering?

Ans: Clustering is the method of grouping the servers together for undertaking excessive percentage of scalability and availability.