Few Daunting Question

1) singleton modification needed in clustered env.

2) https 443 works

3) in process memory cache

4) permsize in java memeory

5) n+1 problem in hibernate

6) bean cycle in spring

7) strategy and command pattern

8) Struts 2 vs Struts 1

9) JSF lifecycle

10) out of memory solution

11) connection pool work

12) CM Db work.

13) Maven usage, diff with ant, POM pattern work on.

14) sync vs async web services

15) rest full statefull services

16) no cookies, url fwd, 80 port dependent, hidden variable proof, noop proof, cross cache system

17) Design ( component off the case study, sub component, functionalities, data flow diagram )

 

Spring Framework Notes.

1) J2ee enterprise java application development using POJO based programming model.

2) POJO being based on non EJB. Hence tomcat application server is good vs weblogic.

3) It uses the ORM framework, quartz, other technologies in modular fashion.

4) Framework covers the checked exceptions off JDBC etc to a unchecked exception very well.

5) IoC helps in tacking application on cheaper economical resources.

6) Transactions managed to local DB as well as JTA compatibility.

7) ID, IoC and Aspect oriented programming (AoP) { works on caching, security, logging and declaration of Tx. }

Spring Architecture

*) The bean factory does the magic of configuring the POJO in the xml and invoking the class on being called by Applicationcontext to run on method. The Lifecycle of the bean is managed by the Spring framework.

*) Spring bean attribute can be scoped to a prototype [ create for statefull bean ]
( pattern of GOF ) or a singleton [ create for stateless bean ]  depending on the need.

*) Init and destroy method for bean class to be xml’ed as attribute to manage the lifecycle of the bean in execution.

Production Architecture’s

In every application development there are multiple aspect to the lab and production setup.

On one side the lab consist of setting up off the dev or QA or regression testing / performance testing environement. The production architecture looks for the deploybility of the application to the various needs of the availability and maintainability.

 

Image from Oracle site

Aspects

1) High Availaibility — The architecture deployment in order to give services to users. Load Balancer takes care of the pinging the server and balance the users on the managed server off the nodes on cluster.

2) Cluster — Application server are deployed as active / passive managed nodes in cluster of weblogic. The in memory session replication helps in maintenance of the user logged in.

3) Load Balancer

4) Latency time and capacity build up

5) Vertical and horizontal scalling

6) Data Recovery and DB failover

7) Disaster Recovery

8) Application failover.

 

[[ under construction ]]

Hadoop Online Tutorial

I found the primary online tutorial very good for basic understanding.

Index as follows ( YouTube Hadoop Tutorial )

1.Hadoop Series Introduction
2.Hadoop Technology Stack
3.Hadoop Distributed File System HDFS
4.Introduction to MapReduce
5.Installing Apache Hadoop Single Node
6.Installing Apache Hadoop Multi Node
7.Troubleshooting, Administering and Optimizing Hadoop
8.Managing HDFS
9.MapReduce Development
10.Introduction to Pig
11.Developing with Pig
12.Introduction to Hive
13.Developing with Hive
14.Introduction to HBase
15.Developing with HBase
16.Introduction to Zookeeper
17.Introduction to Sqoop
18.Local Hadoop Cloudera CDH VM
19.Cloud Hadoop Amazon EMR
20.Cloud Hadoop Microsoft HDInsight

The free download books.  [ Hadoop the definitive Guide by O. Reilly ]