Java updates

  Caching... Save network calls Avoid repeated computations. https://www.youtube.com/watch?v=U3RkDLtS7uY cache policy Least recent used (LRU) Sliding window Global cache (Indenpedently Redis) Write through -> HIt the cache & do update and write to db Write Back -> hit the db and remove the entry in the cachehe REDIS In Memory data store (db, cache messaging) REDIS -java apil (Jedis) Java CRUD using REDIS https://www.youtube.com/watch?v=eYfopvusG_s

#) What type of Data Model used in your current project. #) Source of Data flow in the current application. #) About WITH clause and               benefits #) How Partitions work in Table's #) What are all the performance            tuning techniques used in your         projects #) How analysis SQL Plane. and a few SQL questions in joins, index. Partitioning : use of partitions, types of partitions and when do we need partitions Performance tuning : a) Steps to tune SQL query, use of HINTS b) Scenario: yesterday query was running fine but today its taking time. How to fix this issue. How to read Explain Plan :  what is nested joins, merge joins & has joins Indexing PL SQL : basic questions like & use of GTMP table to aggregate data. Second highest salary within a department – give an example of WITH CLAUSE, ROW ID, ROWNUM, etc. ...

What is 3DNS? http://ramsakal.blogspot.com/p/3dns-what-is-3dns-and-how-does-it-work.html

Day to day activities What is the project model did you worked on before? what is the development you work?  what challenges u faced in the past. How you handle the situation How many resources you handle. You reporting to whom? In case of any technical discussion or proposal with the client, what is your role?  How much you save the cost for the client for the last project? Do you have Hands-on experience in  Java technology? Suppose, I want to develop a system Data would be tree format, object, key and value, unstructured order. How you design What is the purpose of API Gateway in microservice and Service registry what tool you used it How you handle the new tech stack and project which you never handle before? How to deploy the java project in the AWS cloud? How to handle the message in the Cloud? what tool u used  Deliver able impact. How u handle the situation If the client manager not giving co-operation. How you handle the situation ...

Which one is efficient in terms of retrieval between TreeMap and HashMap What is an atomic operation and synchronized in Java? We have ReST Service and multiple clients accessing it. How do you handle the count of calls to ReST Service from these clients including concurrent calls We have Hive Tables - Emp Table and Dept Table and a join query to get employee name and department name on join condition empId == deptId. Can you explain internal execution of this hive query? Explain the mechanism of Mapper Output related to Reducers Input. What is the default partitioner used in Spark? How to handle data skew and cleansing operations? Do you know about Spark Execution Memory Model? Since you have 15+ yrs of exp, what type of role are you looking at (Non-Technical)  Explain purpose of Spring Profiles How do you find the middle node in a singly linked list without using any built-in functionality? When we try to p...

General ====== Design immutable class? Why instance variables are final? Polymorphism How to immutable the Date class? LocalDate or LocalDateTime (Java 1.8) Print sequence using 3 threads in java https://java2blog.com/print-sequence-3-threads-java/ Explain current project architecture? What is the mean? What is VaR? What is Historical simulation? Find the middle index of the given array or collection? Find if the list is cyclic or not? Explain current project architecture? what is lock which one is better synchronization or lock API What is complexity? web service difference between REST and SOAP. Another way of transferring data than web services Object to XML conversion Annotation use in POJO classes in rest services. Thread ======= No of way to create a thread.   Difference between Callable and Runnable. The print alternate number using two threads and so on. (Even and Odd Thread) Difference between CyclicBarrier and CountDownLatch? https://javah...

Java 8 lambdas Why Lambdas? Enables functional programming Readable and concise code - eliminate the boilerplate code Easier-to-use APIs and libraries. Enables Support for parallel processing - Functional Programming read the more readable code or maintainable code Problem in OOPS Everything is an object All code blocks are associated with classes and objects. public class Greeter {  public void greet(){   System.out.println("Hello World");  }  public static void main(String[] args) {   Greeter greeter = new Greeter();   greeter.greet();  } } Output: Hello World Passing Behavior in OOPS The problem of the above program. greet() method always print the "Hello World" message. If you want to print the different message on each time the greet method called. accept the argument. greet() method needs to know what to do. that is not an elegant design. Have an interface as the argument itself and met...

Command Query Responsibility Segregation (CQRS) SOLID Design Principles Microservice Oauth2 Do we need to pass Oauth2 for each services? Where do you check the roles in the code (db or code level)? How one service communication with other microservice? How the Hystrix working in Microservice? How to monitor the microservice? What is event driven? How will you achieve? What is Kafka? How they are using? CORS? How it is working internal? SpringBoot? Stream type Java 8 - Serial and Parallel? CICD? How to implement unit testing, Regression testing Pipeline in Jenkins?

Bids/Proposal/Contracts/Tender RFP (Request for Proposal) Includes each and every detail,  - Identifying Problems - Focus on issues, - Solution, Technical and commercial details - Financial details, cost and budget with Schedule - Specification of work - Qualification of vendors  understand overall idea of what you want from suppliers. Who you are, What you do, What you stand for Scope of the work: Write out what you want, detailed list, expected outcomes Outcome & performance standards - Basic Minimums, what should be accomplished, How you monitor suppliers Deliverables: What all do you Expect to receive. An inventory list. Terms & Conditions : Legal stuff Payments Incentives and Penalties : How we will pay them, what happens If things go wrong. Contractual Terms and Conditions  Requirement for Proposal preparation: What do you want them to give you Evaluation & Award process: How will win the bid. Process Schedul...

Spring Boot: Reference Material: https://www.javatpoint.com/spring-boot-tutorial https://www.javatpoint.com/spring-boot-interview-questions Sample Example import  org.springframework.boot.SpringApplication;   import  org.springframework.boot.autoconfigure.SpringBootApplication;      @SpringBootApplication    public   class  SpringBootExample3Application {           public   static   void  main(String[] args) {           SpringApplication.run (SpringBootExample3Application. class , args);       }   }   Java 8 Features: https://www.javatpoint.com/java-8-features

Terabytes… Petabyte…   Exabyte …What Are They? • Bit = Binary Digit • 8 Bits = 1 Byte • 1024 Bytes = 1 Kilobyte • 1024 Kilobytes = 1 Megabyte • 1024 Megabytes = 1 Gigabyte • 1024 Gigabytes = 1 Terabyte • 1024 Terabytes = 1 Petabyte • 1024 Petabytes = 1 Exabyte • 1024 Exabytes = 1 Zettabyte • 1024 Zettabytes = 1 Yottabyte • 1024 Yottabytes = 1 Brontobyte • 1024 Brontobytes = 1 Geopbyte x

NoSQL is an approach to databases that represents a shift away from traditional relational database management systems (RDBMS). To define NoSQL, it is helpful to start by describing SQL, which is a query language used by RDBMS. Relational databases rely on tables, columns, rows, or schemas to organize and retrieve data. In contrast, NoSQL databases do not rely on these structures and use more flexible data models. NoSQL can mean “not SQL” or “not only SQL.” As RDBMS have increasingly failed to meet the performance, scalability, and flexibility needs that next-generation, data-intensive applications require, NoSQL databases have been adopted by mainstream enterprises. NoSQL is particularly useful for storing unstructured data, which is growing far more rapidly than structured data and does not fit the relational schemas of RDBMS. Common types of unstructured data include: user and session data; chat, messaging, and log data; time series data such as IoT and device data; and large ob...

Cloud Foundry (PaaS) is available as a stand-alone software package. You can, of course, deploy it on Amazon’s AWS, but you can also host it yourself on your own OpenStack server, or through HP’s Helion or VMware’s vSphere. First of all, though, to be completely clear, just what is a Cloud Computing platform? There are, broadly speaking, three major categories of Cloud Computing: Infrastructure as a Service (IaaS) , which provides only a base infrastructure, leaving the end user responsible for platform and environment configuration necessary to deploy applications.  Amazon Web Services  and  Microsoft Azure  are prime examples of IaaS. Software as a Service (SaaS ) like Gmail or Salesforce.com. Platform as a Service (PaaS ) , which helps to reduce the development overhead (environment configuration) by providing a ready-to-use platform.  PaaS services  can be hosted on top of infras...