IBM Interview Questions

These are the interview questions which asked on 17-04-09 by IBM intial round. One thing should remember by everyone, now a days all the companies who are taking WAS admins they are asking questions on O/S also, like Linux or UNIX. So be prepare for those operating systems also before attending an interview.

1. Tell me about yourself (roles and responsibilites)
2. What is the difference b/wn appserver and webserver?
3. How do u configure the plug-in file?
4. How do u configure JDBC drivers and what is meant by J2C authentication?
5. How Internet Works?

A) The Internet is a global system of interconnected computer networks that use the standardized Internet Protocol Suite (TCP/IP). It is a network of networks that consists of millions of private and public, academic, business, and government networks of local to global scope that are linked by copper wires, fiber-optic cables, wireless connections, and other technologies.
6. Explain the process of Federation?
7.How do u administrate admin console in unix?
8. what are the different types of clustering? done
9. What is the advantages of Vertical Clustering?
10. Do u have any idea or did u work with JACL scripts?
11. Where do you find the problems of a Webserver(Log file)?
12. How many types of log files are there! What are they!
13. What is log rotation policy?
14. Where do you enable the Garbage Collector?

using -verbosegc in startup command
15. How to tune an application?
16. When you will perform Thread Dump and Heap Dump?
17. What are the parameters that to pass while generating an Heap Dump?
18. How To identify that heap memory is decreasing and where?
19. Describe the real time problems that u faced in your administration career?
20. What are the major tasks you solved?
21. What is the difference between SSH and Https?
22. Why we enable SSL on webserver rather than App.Server?

A) When ever request comes to application it is start working from Webserver.

SSH

Secure Shell (SSH), sometimes known as Secure Socket Shell, is a Unix-based command interface and protocol for securely getting access to a remote computer. It is widely used by network administrators to control Web and other kinds of servers remotely. SSH is actually a suite of three utilities - slogin, ssh, and scp - that are secure versions of the earlier UNIX utilities, rlogin, rsh, and rcp. SSH commands are encrypted and secure in several ways. Both ends of the client/server connection are authenticated using a digital certificate, and passwords are protected by being encrypted.

SSH uses RSA public key cryptography for both connection and authentication. Encryption algorithms include Blowfish, DES, and IDEA. IDEA is the default.

SSH2, the latest version, is a proposed set of standards from the Internet Engineering Task Force (IETF).

How To Connect To WSadmin Console through SOAP ?

Generally we connect wsadmin console directly with soap port or rmi port.
specially if we want to check whether a particular SOAP port of dmgr is working or not, this requisition we need whenever we are federating a node to a dmgr.
The following is the command which we use to check whether a particular port is communicating or not.

wsadmin -conntype SOAP -port 8879

wsadmin -conntype RMI -port 9809

wsadmin -conntype RMI -port 2809 -user u1 -password secret1

(1.1) Issues: we got responce from users saying that they not able to receive messages from their application.

Sol : we identified that message receiver server not able to recive messages from MQ, because of File storeage failed, then we informed the same to system infrastructure team they added SAN, even though the problem not got resolved.

I am seeing some transaction timeout errors in the logs:####<21-Jul-2009 16:18:23 o'clock BST> <21cnedc313>

(1.2) Issues: JMS transaction timeout messages like this in WAS.

Sol: there are bulk number of JMS messages stored in MQ Server, when ever san got added at a time all the messages in MQ, hit the server at a time, so server is not able process that many number of requests at a time, then we increase the JTA transaction time out value from 30 to 100, this will allow more time for transaction to complete. After process all the requests we changed the transaction time out value back to 30.

(2.1) Issues: the WAS server logs are not getting generated in both the nodes. The last timestamp in the logs file is 18/07/09 15:36.The same issue has occurred few times and we have to restarted both the managed servers for the logs to be generated.

Could you please let us know what could be the reason for this issue?

Sol. The log rotation was not set properly, which I have set now. Also the log stopped in the middle of printing some debugs, which suggests that it ran out of disk space. The /IBM_profile is mounted on root partition.

(3.1) Can you please send the P2 case (TAM Test Tool not working) which came today morning to APLSUP54 and request them to check why the ?java.lang.OutOfMemoryError: unable to create new native thread? occurred.

Also mention in that case that we had taken the thread dump and is present at mps location.

Sol. This is again a native memory issue. The JVM heap allocated is 1.5 Gb (which is necessary otherwise app starts giving heap errors), which leave 512mb for native memory out of the possible 2Gb max.

This native memory is used by all the native modules like MQ or application codes creating native memory. If the native memory is not sufficient then you get OutofMemory:unable to create a new native thread error.

(4.1) We are facing problem with the WebSphere server in dybip04. We are using BEA version 8.1SP6

The Managed server is suddenly going into UNKNOWN state and when we try to restart the server

The following error is occurring::

OutOfMemoryError occured on server

Sol. I have increased the memory size to 2GB and restarted the server. The messages are being consumed now.

5.1) we are facing connection failure error, due to what causes?

Sol. Finally we found, driver there is one DB driver corrupted in it causes the issue.

Firewarll -> loadbalancer -> Webserver -> app.ser visa plugin -> hits application -> contact db to ds and

request - > firewall -> loadbalancer(split the load into multiple Webserver) -> (sitemider/ssl) webserver -> via plug in which is in the application server -> application

In side cluster jvm will respond.

How much memory tuned for your application servers in your environment?

Depend upon the application, decided by developer. Or depends on OS.

How will you login to solaris/ linux for installations?

Normally we will not use rout privileged ID for installing/configuring was applications in Linux.

Ex: empid

Su wasuser(not root privileged user) Non-route user

What are the two basic steps that admin have to do after deploying the application & before running the application?

have to regenerate the web server plug-in, copy it over to the web server machine and do a quick restart of it

1.wht is hot deployment, and where we get a chance to go for this?
Hot deployment means adding modules or additional services to the existing application or new application without stopping the application server as well as application. When an application is went to Production environment then we can't stop the application as application requests will come. So in that case we will go for hot deployment.

2.Can we access 2 different applications at once running on 2 application servers in a cluster?

If those two applications are mapped exactly on to the same cluster members, we can access for them by configuring the webserver and plug-in properly for the cluster.

3.how to enable Global Security in WAS though CUI?

To enable Global Security first we have to do
1. Select the Authentication Registry, i.e., either Local OS or LDAP.
Here we have to specify the primary administrative user name which should be present there in the registry.
2. Select the Authentication Mechanism i.e., LTPA or SWAM.
Here we have to specify the password and confirm-password.
3. Enable Global Security.
4. Save and restart the server.

4.If the app server crashes in the middle of application deployment , wht could be the reason and wht steps we have to follow?

If the server resources are less while deployment, when application requests are hitting application server due to less resources the application server will crash. If the application server crash then that time we can get thread dump.

5.During WAS ND installation, one default server "server1" creates right?can we change its name during installation?

If we are installing, in silent we can change the default server name we can change, in GUI its not possible.

Q: What is the default port for SSH server?
A: 22

HSBC Interview

These are the interview questions which are asked in HSBC.


1. What is JavaBean?

A) A JavaBean is a Java Object that is serializable, has a nullary constructor, and allows access to properties using getter and setter methods.
2. What is difference between soap.client.props and sas.client.props?
3. What is difference between normal JVM and Web sphere JVM?
4. What are the securities in Web sphere?
5. What is DD/Deployment Descriptor?

A) a deployment descriptor describes how a web application or enterprise application should be deployed. It directs a deployment tool to deploy a module or application with specific container options, security settings and describes specific configuration requirements

6. What is the deployment descriptor of EAR?

A) as below
7. What is the deployment descriptor of EJB/WAR?

A) ibm-web-bnd.xmi, ibm-web-ext.xmi, web.xml
8. How do you package applications?
9. What is difference between context root and url-pattern?
10. Workload management
11. What is vertical and horizontal scaling and their Advantages and Dis-advantages?
12. How do you configure LDAP and Web sphere?
13. How do you enable global security?
14. How do you find memory leaks? At what situation memory leaks occur –Give any 3

examples? Is there any tool to find memory leaks?
memory leaks in hapen if objects not closing in java program

15. How do you enable verbose GC? In what file, the output is written?
16. When does GC cycle starts?
17. What is OutOfMemory exception and when does it occur?
18. What are your Day-to-Day Activities?

IBM INTERVIEW Questions on 04-05-09

1. Tell me about your educational background.
2. Tell me about your day to day activity.
3. what is load balancing?

A) Edge component, BIGIP product hardware load balance.

It will be connected to router and switches, Webserver – to – app. server load balancer
4. What is Work Load Management?

A) Failover, High availability, scalability and security are coming from Clustering (WLM).

Two main features are - Load Balancing - AffinityWebSphere WLM is offering these two features on different levels like - Application/web Server Clustering

5. what is meant by profile? How many types of profiles are there in Was v6.0?

A) 3 types of profiles in 6.0 1.application server , 2. dmgr, 3.default

in 6.1 there are 4 – 1.dmgr, 2.app.serv, 3.default,4.cell profile(already federated appserver profile)
6. how you fedarate a node from deployment manager? and how you federate when global security is enabled.?

A) we can federate it from console, need to select Node under system administration section, then select a new node button then provide required(soap port) data.
7. What is SSL ? hOW You configure SSL?

A) It is Already been configured will use dummy, web server part, certificate, configure in that virtual host.
8. What is meant by Horizontal Clustering? Explain?

A) DONE
9. How to check disk usage in linux or unix?

A) Du -k
10. How to check the multiple NIC in Unix or linux?

A) ifconfig -a
11. How to identify and kill a process ID?

A) Ps –ef
12. What are the measures you follow while deploying an application in production environment?

A) we need to consider below steps.

1. need to take necessary backups, 2. Raise a change request, 3. Approval request, 4. schedule date from change control.
13. what is the use of trace.log and activity.log?

A) we can use “showlog” commad in bin directory for getting tracer information.
Trace.log : It will have details about the WAS Environment, understandable text format.

Activity.log : It will have complete information about Application server environment, and it is not in readable format, “waslogbr.bat” for opening/viewing this log. It will have information about complete base class and other stuff. We have to use “symptom database” for fixing/compare identifying the issue.

15. where do you get performance information in log files of an application server?

A) there are 2 logfiles

1. NativeError.log – at what state the GC happened and how much memory freed up.

2. NativeOut.log – it is having general logs.

IBM Chennai Interview

1. Are you responsible for production support?

A) Yes

As per on call support, we have dedicate mobile and laptop every week, they will change. And Prioritize, change at every week on 24x7 basis.

2. Breifly explain about the topology of production environment?

A)

In my production environment we are having 200 applications running across 70 RHEL boxes in 20 WebSphere cells.

Each cell has 3 nodes under dmgr, all nodes are established in horizontal cluster (different RHEL boxes), All clusters will have 3 jvms run across the RHEL boxes.

Resources: 8 onsite + 8 off shore

Role hierarchy: Business head -> IT MGR -> Middleware mgr -> off-shore team lead ->

My role is Level-1 and 2.

We are did a migration from 5.1 to 6.0/6.1, in my environment, 5.1 will be completely migrated this year end. We are using paid support from IBM 5.1(3 cells) as free support stopped by IBM.

3. Which environment you are using?

A) Soloaris 6.1/8.x , RHEL Linux: 5.1
4. How many servers and how many applications?

A) Discussed
5. which kind of applications?

A) Client Business:

1. Mortgage, 2.Trading applications
6. Applications are running on clusters?

Yes.
7. How do you verify that you are using Horizontal clusters not a vertical cluster?

A) if u have all the servers in same machine(Host) ,than its vertical ,if cluster servers are installed in different machine than its horizontal.

-OR-

Go to WAS console => select Nodes in left side => in the right side of the console you can see how many nodes make's your CELL, and also the hostname of the boxes in which the node exists.
if you see all the nodes from different hostnames then its Horizontal clustering if you see same hostname here then its Vertical clustering

8. your cluster contains how many nodes?

A) 3 nodes
9. Both nodes are running on dmgr. Dmgr is on both nodes?

A) All my production Dmgr in a single box. Nodes will be across different boxes.

Note: if in case failure of DMGR node, then how do we handle the issue?

In that case we need to wait till that problem gets resolved, for any configuration changes in the console. Generally start and stop server activities will do in application server node.
10. Is it necessary to have dmgr on both nodes?

A) NO, Single dmgr.
11. Do you have dmgr as standalone?

A) We can, but No use.
12. Can we create more than one server in standalone-environement?

A) Never worked on stand alone environment.
13. can we have more than one application in a single server?

A) many
14. I want to depoly the application in any one of the node but not cluster?

A) Node is a server
15. What kind of database you are using?

A) Oracle 10g
16. What kind of security mode you are using or JDBC connection?

A) J2C Authentication
17. What type of driver you are using? Type 4 driver

A)

Type 1 driver: JDBC-ODBC Bridge

This driver called as JDBC-ODBC bridge.The Java Statements converts to JDBC statements.JDBC statements calls ODBC by using JDBC-ODBC bridge. ODBC drivers convert into the requirements of databases.

Java--->JDBCStat-->JDBC-ODBC bridge-->ODBC-->Databases.

Type 2 driver: Native-API/partly Java driver

This driver is called as Native Driver where it requires the some native code to connect to the databases.

Type 3 Driver: Net-protocol/all-Java driver

This driver is called as Protocal driver where

Java-->JDBC statements-->SQLStatements--> databases.

Type 4 Driver: This driver directly converts the java statements to SQl Statements which require to databases. It wont convert to JDBC statement.

18. The application should be authenticate before interacting with database?

A) It will happened, we are creating uid, pwd that will work
19. what is meant by connection pooling?

A) a connection pool is a cache of database connections maintained by the database so that the connections can be reused when the database receives future requests for data. Connection pools are used to enhance the performance of executing commands on a database. Opening and maintaining a database connection for each user, especially requests made to a dynamic database-driven website application, is costly and wastes resources. In connection pooling, after a connection is created, it is placed in the pool and it is used over again so that a new connection does not have to be established. If all the connections are being used, a new connection is made and is added to the pool. Connection pooling also cuts down on the amount of time a user must wait to establish a connection to the database.
20. what are the different methods to deploy application?

A)
21. for ear file is context root is necessary?

A) Hostname:9089/appname - context root Yes.
22. I updated the new application but the user is getting the old applicaion only?

A) need to Restart, synch
23. what are the options you have to improve performance?

A) Connection pool, Thread pool of web container, EJB container, web server parameter, jdbc connection pool

Tuning Application server

Tuning JVM, Tuning Applications, Tuning Database, Tuning JMS, Tuning security, Tuning operating systems, Tuning Web servers

Connection pool perameters:

$AdminControl getAttribute $objectname surgeCreationInterval

$AdminControl setAttribute $objectname surgeCreationInterval 30

$AdminControl getAttribute $objectname surgeThreshold

$AdminControl setAttribute $objectname surgeThreshold 15

24. to sepcify the weight of a cluster member in which file i have to modify?

A) have to modify in Plugin file
25. I am getting server 500 erro, what will be the reason?

A) Internal server error (server to db middleware)
26. How do enable GC?

In the Administrative Console, expand Servers and then click on Application Servers.

. Click on the server that is encountering the¬ "OutOfMemory" condition.

. On the Configuration tab, under Server¬ Infrastructure, expand Java and Process

Management, and click Process Definition.

. Under the Additional Properties section, click Java Virtual¬ Machine.

. Select the Verbose garbage collection check box.¬

. Click¬ Apply.

. At the top of the Administrative Client, click Save to apply changes¬ to the master

configuration.

. Stop and restart the Application Server

The verbose garbage collection output is written to either native_stderr.log or

native_stdout.log for the Application Server

verbosegc – Tells you what is being done, whether heap size is at min or max.

27. Ho to check GC is active or not, if you don't have?

A) We can check in logs.
28. can you tell me about profiles?

A) WebSphere application binary, profile sharing binaries of existing instance,
29. what is the use of virtual host?

A) Configuration that lets a single host machine resemble multiple host machines. Each virtual

host has a logical name and a list of one or more domain name system (DNS) aliases by which

it is known.
30. Is webserver & application server should be installed in a single machine or different machines?

A) We can do it, but in production different machines.

Webserver OS tuned in different way, app. server different way, normally these web servers in DMZ - Demilitarized Zone.

31. Difference between managed node and unmanaged node?

A) Managed have node agent, unmanaged not. Unmanaged node we not control from console.
32. How to check application servers are running/not?

A) Ps -grep
33. How to check WAS is running or not through PS?

A) Ps -grep

WAS Edge Components

These are the some of the WAS Edge Components.

WAS Edge Components

Caching Proxy
Proxy Server
Load Balancer
Network Dispatcher Component
Content Based Routing (CBR)
Site Selector Component

Barclays Interview

1. What is session affinity?

A) Is nothing but a persistence.

Most servers use the term “Session Affinity” to indicate that with in a cluster of servers, requests from the same client always get routed back to same server. This eliminates the need to replicate session data like HTTP session or Stateful session Beans.

2. JVM which has been clustered, the server is in production?

A) 1. Memory to memory replication 2. Database persistence

Heartbeat mechanism work in a cluster, member of the cluster identifies that the other server is not responding it checks 3 times for every 60 seconds, if not responded then it takes the configuration using memory replication process then completes request.
3. What is fix pack?

A) Patches to fix a particular issue for a particular in environment only not other.
4. What is patch?

A) It is like independent to every body, bug fix of WAS. WAS 6.1.0.17
5. What is migration? How can you migrate from one version to another version?
A) discussed

5. How can you disable the security without admin console?

A) we can disable in Security.xml, but we can’t enable.
6. Complete configureation steps for SSL?

A) We have to install ibm http server, by using ikeyman tool we can create and use SSL certificates.
7. How to configure session management?

A) we can configure though console, either in application/deployment descriptor.
8. How can you provide security authentication for web server?

A) eTrust SiteMinder tool
9. How to know webserver version?

A) we can find in Logfile.
10. How to identify old and new context roots?

A) in Httpd.conf file we can see commented(old) and uncommented(new) data.
11. Difference between v5 & v6.

A)

1. Multiple Profile creations with a single installation (All profiles share same WebSphere binaries)

2. Introduction of Service Integration Bus (SIB) for messaging

3. Has default JMS providers

4. Supports mixed version nodes in a v6 ND Cell

5. Has some extra add-ons in the Admin console navigation tree

6. JACL has been deprecated in 6.1

12. What is the difference between WAS and WL?

A)

1. In weblogic u cant do clustering accros the domain,but in Websphere u can.

2. In weblogic all the configurations are stored in a single file called Config.xml ,but in Websphere its stored in a directory structure called CELL

3. In weblogic u can start the managed server without a Adminserver(using MSI-config.xml),in websphere u can not start a node with out Dmgr.

4. In websphere u can add webserver as a unmanaged node where as u cannnt do that in weblogic.
13. How many types of installation are there?

A) GUI, using Response file (silent mode), command line .
14. JACL scripting? Alredy discussed
15. If the performance, of the appliacation goes down? what will u do?

A) Performance Information should collect from monitoring tool
16. what is the difference between L1, L2, L3?

A)

l1- is basic level (monitoring, basic configuration)

l2 -back up who are senior staff (trouble shooting)

l3 –architechts (designing / architect/ requirement(ram/box))

17. the uesr submitted the request, when that request is on processing in the middle the server crashes then what happens?

It will lost.

Websphere application server interview Questions

Here is the major websphere application server interview questions collection and answer

Wells Fargo 16-07-09

1) What are your daily day to day Activates?

A) We have ticketing tools, We have 2 Type of tickets:

1. Change request : scheduled activities like new resources creation, JVM settings, Configuration of the application and development teams raised tickets

2. Incident request : production support or monitoring like up gradation.

We have a dev team; if they found any issues they will raise a ticket.

We have a production support team, and Monitoring team, if they come across some thing abnormal then they will raise a production support tickets.

We are having WAS 5.1 and 6.1, so daily we are having configuration setups for migration, and building the similar environment as 5.1 in 6.1In different boxes as new environment.

Right now I don’t have chance to write new scripts. How to check thread dump in jacl

How do you check the health of the appserver? Is there any tool is avialable with you?
A) We have monitoring tools, at the time issue only, TPV (Tivoli Performance Viewer)/Willy Introscope, and normally it is disabled, at the time of performance issue only we will do monitoring.

2 kinds of monitoring: 1. Availability, 2. performance monitoring 24/7 or not.

L1 team using SiteScope: SiteScope WebSphere Performance Servlet Monitor to monitor the server statistics of IBM WebSphere Server (versions 3.0x, 3.5, 3.5.x, and 4.0) via a WebSphere Performance Servlet. The error and warning thresholds for the monitor can be set on as many as ten performance statistics.

3) Can u configure multpile apache webservers?

A) we can configure in httpd.conf file.
4) Is it possible to configure 10 domain names in apache? if yes? How?
A) we can use virtual hosts.

5) How do you perform heap dump and thread dump?

A) Kill -3 <>
Heap dump relate to jvm memory usage,

Thread dump relate jvm thread usage

6) Is kill -3,kill a process or create a thread dump? explain!

A) kill -3 is used create thread dump.
7) Did u work with any tools which helps you to see the heap dump or thread dump?

A) Heap dump jmap, IBM heap analyzer tool, thread dump using IBM thread analyzer /samurai

8) How to configure security and LDAP?

A) Global security,

Security availability: 1. OS security 2. LDAP (3^rd party security) 3. Custom security(Application from DB)

9) What are 202 errors?

Accepted.
10) In ls -lrt, what t stands for and r stands for l stands for?

A)

-l shows you huge amounts of information (permissions, owners, size, and when last modified.)

-r reverses the order of how the files are displayed.

-t shows you the files in modification time
11) How to check a particular port is working or not in unix?

A) netstat -a | grep 80

IBM Hyderabad

1)Tellme About yourself?

A) Worked as a Websphere administrator. Was responsible for deploying, configuring,

tuning, clustering, and troubleshooting WebSphere related issues.
2)Configuration of WebServer with AppServer?

A) This configuration available in httpd.conf file of a web server, in this file we will configure virtual hosts and domains etc .
3) Role of Plugin-Cfg.xml?
A) When ever request comes to Webserver it identifies the app. server configuration in this configuration file.

4) Tell me about RemoteConfiguration?
5) How do you deploy an application in AdminConsole?
6) How do you deploy an EAR file in admin console?
7) What is meant by default bindings?

A) It will bind the resources to connect….at time of startup
8)What are precompiled jsps?
9) Are you comfortable with MQ?

A) I have a little bit knowledge.
10)Tell me about MQConfiguration with WAS?

A) We will configure from console, resources -> JMS -> Queues-> integrating with MQ.
11) Tell me the command to find RAM size in AIX/Unix?
A) prtconf only for AIX

12)Command to find diskfree space?

A) Df –k or m
13) how do you provide Custom security?

A) Developer will give the authorization from an application(may be uid/pwd from Oracle DB)
14)Suppose if u enable customsecurity after opening the admin console in the rightside suppose if you got only 2 options instead of 3 then what to do?

A) question not clear
15)How much you are comfortable with scripting(JACL/JYTHON)?

A) I have little bit knowledge.

Set $

puts "About to dump threads for this jvm..."

$AdminControl invoke $jvm dumpThreads

puts "... done"

------------

Invoke the generateHeapDump operation on a JVM MBean, for example,

Finding JVM objectName:

set objectName [$AdminControl queryNames

WebSphere:type=JVM,process=<servername>,node=<nodename>,*]

Invoking the generateHeapDump operation on JVM MBean:

$AdminControl invoke $objectName generateHeapDump

Ex: wsadmin -f test.py a b c

test.py content:

import sys

first = sys.argv[0]

second = sys.argv[1]

third = sys.argv[2]

arglen = len(sys.argv)

16)In Jython script how to invoke a variable which was defined in another jython script?

Using MBeans

Calling scripts using another script

Use the execfile command to call a Jython script from another Jython script. For example:

Create a script called test1.py that contains the following:

execfile('c:/temp/script/testFunctions.py')

print printName('Cathy', 'Smith')

Create a script called testFunctions.py that contains the following:

def printName(first, last):

name = first + ' ' + last

return name

Then pass the following path as a script argument:

wsadmin -lang jython -f 'c:/temp/script/test1.py'