Sunday 4 November 2012

DEFINITIONS IN WAS


         DEFINITIONS IN WAS


1) What is WAS ? (WEBSPHERE APPLICATION SERVER)



A) ----> It provides run time URL for the end user.

    ----> This technology is Introduced by IBM Company in to the market.

    -----> It is easier for clients to build , deploy , manage Dynamic Websites.

   -----> It is also used  E-Business Applications.


   -----> The application is Secure , Scalable , Reliable.


   -----> WAS provides Authentication and Authorization to secure applications.





FUNCTIONALITY OF WAS ?

----> WAS supports Asynchronous Messaging through JMS Provider

-----> WAS provides Authentication and Authorization to secure applications using LDAP.

-----> WAS works with Web Server (IBM HTTP SERVER)




2) What is Edge Component ?

A) ----> It can reduce Web Server Congestion.

    -----> Increase Content Availability 

   ------> Improve Web Server performance.

   ------> It runs in a network configuration between Enterprise Intranet and Internet.




3) What is WEB CONTAINER ?

A) -----> It process HTTP requests , Servlets , Java Server Pages.

    ------> It process static requests or provides environment for running Servlets.




4) What is EJB CONTAINER ? 

A) -----> It is used for Business transactions through Database (Dynamic data)

    ------> Provides all Run time Services needed to Deploy , Manage

   ------> Provides an environment for running Servlets.

   ------> It is Server process that handles requests for both session and Entity Beans.

   ------> EJB has 2 types

1) State full : We can get Acknowledgement from the client side.

2) State less : No Acknowledgements from client side.




5) What is Web Server ?

A) ----> It process HTTP or Static requests.

    -----> It uses Server side scripting , Java Script .

   -----> It uses browser for viewing the application.



6) What is App Server ?

A) ----> It process Dynamic requests and also handle Static requests.

    -----> It takes of Security , transaction , Load Balancing , Clustering , Connection Pooling.




7) What is Session Affinity ?

A) ----> when ever one request comes from same client it should routed back to the same Server.

    -----> Affinity means request comes again and again.

    -----> When HTTP Session ID is created it is passed back to browser as a part of Cookie .

    -----> When browser further makes request Cookie will sent back to the Web Server.

   -----> Web Server PLUG-IN examines the Session ID and extracts unique ID and forwards the request.


8) What is Session Persistence ?

A)  -----> It is used permanently store data from HTTP Session object to enable further and Load Balancing across Cluster.


9)  What is Session Tracking ?

A)  ----> It enables to track users progress over multiple Servlets or HTML pages.

     -----> It is State less (we cannot get Acknowledgement)


10)  What is Output file ?
  
A) -----> Creates new file in bin directory that includes Current Date

     -----> websphere Config -yyyy-mm-dd.zip



11) What is Connection Pooling ? 

A)  ----> Connection Pool is used as Cache(Speed up) of database Connections maintained so that the connections can be reused for further requests to Database.

     -----> Opening and maintaining a Data Base connection for each user


12)  What is Heap Dump  ?

A)  -----> It is used when sufficient memory is not available for a new object

      -----> It generates a dump of all live objects that are on the Java Heap.

      -----> By default we get OutOfMemoryErrors because of JVM crashes 

     ------> Heap dump is created in < profile-root > directory when OutOfMemoryErrorException is thrown

    ------> When JVM crashes we cannot get any application.


13) What is Thread Dump ?

A)  ----> It provides detailed information of all active Java Threads.

    ----> It is used to know how many threads are there in Connection Pool 

    ------> How many are there in Dead lock state.


14) How to generate Thread Dump  ?

A) Kill -3 Pid


15) What is Activity log  ?

A)  ----->  It is also called as IBM Service log file 

     ----->  It will have complete information about Application Server environment

     -----> It is not in readable format

    ------> We have to use one log file to view the complete information of any application

   -------> waslogbr.bat : For Opening and Viewing this log (It will have complete information about base class and other applications)

   -----> We have to use Symptom database for fixing or compare identify the issue.


16)  What is Trace log  ?
                 (or)

        What is Trace   ?

A)  ---->  It will have details about WAS environment in understandable text format

     -----> Trace file contains Step by Step activity details of WAS process.

    -----> Trace file shows the time and Sequence of methods.

    -----> We can use 'showlog' command in bin directory for getting tracer information.

Trace  :  It is an informational record that is intended for Service Engineers or Developers to use


17)  What is SSO ?

A)  ----> SSO means Single Sign On)

     ----->  Once if we login or give User id and Password no need to give again and again.

    ------>  Once a Client had a valid LTPA Token they need not re authenticate again with in a Cell


18)  What is Virtual Host  ?

A)   -----> It is a Configuration that enable single host machine to resembles multiple host machines

      ----> It is the combination of IP and Port Number or host name.


19)  What is Fix Pack and Refresh Pack  ?

A)  ----> Fix Pack fixes certain issues.

     -----> If you got any problem then we have to raise the PROBLEM MANAGEMENT REPORT to the IBM Service engineers they will provide a fix to that problem

     ----> Up to 6.1 version 43 FIX PACKS have been issued.

   Refresh Pack :  It is a mile stone for release it takes you to release say 6.0.0.1 

        -----> Means it is like a release of new movie or software into the market.

       ------> If you use rp2 it becomes 6.0.0.2 

      ------> If you apply fp35 it becomes 6.0.2.35 which is not a release 


20)  What is SSL  ?

A)  ----> SSL means SECURED SOCKET LAYER.

     -----> SSL is also a PROTOCOL 

     -----> It also provides secure communication between data integrity and Encryption over the network between the nodes

     -----> It is a process of integrating Client and Certificate from browser.


21) What is Collector Tool  ?

A)   ---->  It is an Agent to configure IBM SUPPORT ASSISTANT (ISA) 

      ----> It collects all information about your WAS installation , Packages , in JAR file which we can send it to IBM ISA in determining and analyzing your problem.

     ----> It can run only on root or Administrator.

                                     (or)

     -----> Collector is a tool which provides all log files. These log files contains failure info. 
      ----> If the bugs cant be cleared by administrator, then by using this tool we will send all log files to IBM people.



22) What is JNDI  ?

A)  -----> JNDI means JAVA NAMING AND DIRECTORY INTERFACE .

     -----> It is used to register the resources hosted by App Server.

    -----> JNDI implements WAS is built on top of CORBA (COMMON REQUEST BROKER ARCHITECTURE) 


23)  What is JDBC  ?  

A)   ----> JDBC means JAVA DATA BASE CONNECTIVITY.

      -----> JDBC is responsible for connection and communication between java applications

     ------> JDBC is an API (Application Programming Interface) that is used to connect to any database.
    
   ------>  Java API is responsible for connecting to your applications


24)  What is JDBC PROVIDER ?

A)  -----> It is a provider that is used to connect to any Data Base

     -----> Means it is a mediator between Client and Data Base

     -----> Vendor details will be present in JDBC providers (Any Vendor MYSQL,ORACLE)

    -----> If we want to connect or execute the program to any vendor or client we have to use one more mediator 

   ------>  Adapter : It is a jar file responsible for communication between java application and database


25)  What is Context Root  ?

A)  -----> Context Root identifies a web application that is stored in application.xml file.

     ----->  Every web application developed with in Web Sphere studio has a Context Root associated with it.

    ------> This Context Root helps to distinguish multiple applications deployed on same Application Server.

  ------> By Context Root only your Configuration file (plugin-cnf.xml) routes the request to particular application
    

26)  What is the Ticket Tracking tool you used  ?

A) USD (UNI CENTRE SERVICE DESK)


27)  What is Profile  ?

A)  -----> Profile consists of ports , collection of files and folders collectively used for providing run time URL for the end user.

3 types of profiles

1) Application profile  : Default profile

2) Deployment profile : Soap Connector port no of DMGR 8879.

3) Custom profile         : Gives Empty node.
   

28)  What is Web Sphere  ?

A)   -----> Web Sphere popularly refers to  IBM Middle ware technology products.

      -----> Web Sphere known for key operation in E-Business Applications.

      -----> Web Sphere has run time components , tools which can help creating applications which runs on WAS.


29)  Security Features present in WAS  ?

A)   -----> Security model for web Sphere is primarly based on Java EE Security model.

      ----->  It also depends on Operating System.

      ------> User Authentication and Authorization mechanisms also provided in WAS.

      ------> LTPA (LIGHT WEIGHT THIRD PARTY AUTHENTICATION) mechanism is main security feature present in WAS.


30)  Features present in Web Sphere  ?

A)   1) Order Management

       2) Web Sphere commerce Accelerator.

       3) Analytical and business Intelligence.

       4) Open standards used JAVA , EJB

       5) Web Sphere commerce payments and Customer care.


31)  Administrator benefits using Web Sphere  ?

A)   ------>  Web Sphere almost reduces the work of server Administrator.

      -------> He can manage load on Servers efficiently.

      ------->  Flexibility to divide load and applications among different Servers.

      ------->  Predict the incoming load on Servers.

      -------->  Email alerts , Restart options , Memory leak detection.   


32)  NETWORK DEPLOYMENT feature present in WAS  ?

A)   ------> It provides hot recovery of single tons which makes you forget about GARBAGE COLLECTED single tons.

     ------>  Transaction logs can stored on Shared file system.

     ------>  In run time Clustering operations of deployment managers role is eliminated.

    -------> J2EE FAILOVER support , Cell configuration support is present.


33) What is Caching Proxy of IBM Web Sphere Edge Server  ?

A)   ----->  Caching Proxy can configured in forward direction or a Proxy.

      ------> Page fragments arising from JSP/SERVLETS are cracked by edge and Caching process is slow.

     ------->  Performance and Scalability of J2EE applications can be increased by edge.


34)  How many SSL Certificate Authorities available in todays market  ?

A)  1) ETRUST

      2) VERISIGN

      3) GEOTRUST

      4) RSA


35Dis Advantages of Memory to Memory replication  ?

A)  -----> Consumes large amount of memory in networks with many users.

     ------> Each Server has a copy of all Sessions.

     ------> When we change a Session it will be replicated to all Application Servers.


36)  What is Symptom Database  ?

A)   ----->  A Symptom is an error or event message.

      ----->  A Symptom Database is an XML file of symptoms , string match patterns , Associated solutions and directives.

     ------>  Log records  can be analyzed using Symptom Database to interpret known events and error conditions.

    ------>  Symptom Databases can be imported from external XML Symptom  Database , saved and exported into an external file in XML format.

   ------> You can either import Symptom Database from local or remote Host.


37)  What is Clustering  ? Types of Clustering  ?

A)   ----->  It is a set of AppServers having same applications Installed,Grouped locally for WORKLOADMANAGEMENT (WLM)

    ------>  Grouping of AppServers under a single application

    ------>  Every cluster member must have the same configuration and same version.We can say each cluster member is the clone to one another. 



  There are 2 types of CLUSTERING   
     
1)   1) VERTICAL CLUSTERING : Deployed the application on one machine and we can run that application on our own box(or) machine.

----> In this Vertical Clustering Machine FailOver is not possible.

----> If the machine gets failed we cannot run that application (or) SINGLE POINT OF FAILURE.

---> If one Server fails the other Server will takes care

----> If machine fails nothing can be done.

-----> But when the physical machine failover happens we will lose every thing


   2) HORIZONTAL CLUSTERING : Grouping of AppServers in which one AppServer should be on one node and Another AppServer should be on another node.

-----> Means if we take two machines one application should be deployed on different machines Remotely (or) one application should run in INDIA and another application should run in AMERICA.

-----> If Machine1 application will be deployed on Machine2 so we have to know the IP address of Machine1 then only it is possible to deployed that application Successfully.

----> Both Machines should have Internet Connection.

----> Here no SINGLE POINT OF FAILURE. 

----> It Supports MACHINE FAILOVER.


38)  How will you fix Memory Leakage in WAS  ?

A)  ----> Memory Leakage issue is in Native code

     ----> For this issue we can need to get Heap Dumps and analyze the Dumps for any Memory issues.

   -----> If we got any issue we need to ask developers to fix this issue.

   ----->  For Temporary purpose we can increase Heap size.

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