Technical Questions

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?

t

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-drivenwebsite 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