Havells IOT Engineer Interview Questions and Answers

Microservices offer benefits such as scalability, flexibility, and easier maintenance.

• Scalability: Microservices can be scaled independently, allowing for better resource utilization.

• Flexibility: Microservices can be developed and deployed independently, allowing for faster iteration and innovation.

• Easier maintenance: Microservices are smaller and more focused, making it easier to identify and fix issues.

• Improved fault...read more

Spring is a framework while Spring Boot is an extension of Spring.

• Spring Boot provides auto-configuration and embedded servers.

• Spring Boot reduces boilerplate code and simplifies application setup.

• Spring Boot is opinionated and provides defaults for configuration.

• Spring Boot is ideal for microservices and standalone applications.

• Spring is more flexible and customizable than Spring Boot.

Yes, I have configured service registry.

• I have experience with service registry tools like Consul and Eureka.

• I have configured service registry for microservices architecture.

• I have implemented service discovery and load balancing using service registry.

• I have used service registry to manage service endpoints and metadata.

Profile registry is used to store user profiles and their preferences in a centralized location.

• Profile registry is used to manage user profiles and preferences in a centralized location

• It can be configured in a project by defining the schema for user profiles and preferences

• Profile registry can be accessed through APIs or SDKs

• It can be used to personalize user experience and provide targeted content

• Examples of profile...read more

Spring Boot is a framework that simplifies the development of Java applications by providing pre-configured settings and dependencies.

• Spring Boot uses an embedded server to run applications.

• It provides auto-configuration for commonly used libraries and frameworks.

• Spring Boot uses Spring Framework's core features like Inversion of Control (IoC) and Aspect Oriented Programming (AOP).

• It uses annotations to configure and c...read more

We can handle the situation by implementing fault tolerance mechanisms.

• Implementing circuit breakers to prevent cascading failures

• Using load balancers to redirect traffic to healthy instances

• Implementing retry mechanisms to handle temporary failures

• Using monitoring tools to detect and alert on failures

• Implementing graceful degradation to provide partial functionality

• Using backups or replicas to ensure high availability

We use @RestController, @RequestMapping, @Autowired, @Service, @Repository, @Transactional, @GetMapping, @PostMapping, @PutMapping, @DeleteMapping annotations in our Spring Boot project.

• @RestController - used to define RESTful web services

• @RequestMapping - used to map HTTP requests to handler methods

• @Autowired - used for automatic dependency injection

• @Service - used to define a service layer component

• @Repository - used...read more

Spring Data JPA simplifies the implementation of data access layer in Spring applications.

• Provides a framework for easily creating repositories and queries

• Reduces boilerplate code for data access layer

• Supports pagination and sorting of data

• Integrates with Spring's transaction management

• Example: @Repository interface UserRepository extends JpaRepository {}

A hash map is a data structure that uses a hash function to map keys to values in constant time.

• Hash map uses an array to store key-value pairs

• The hash function is used to convert the key into an index of the array

• Collisions occur when two keys map to the same index, which is resolved using chaining or open addressing

• Retrieving a value from a hash map involves computing the hash of the key and then looking up the corre...read more

Comparable is an interface used for natural ordering while Comparator is an interface used for custom ordering.

• Comparable is implemented by the class itself while Comparator is implemented by a separate class.

• Comparable provides a single method compareTo() while Comparator provides a single method compare().

• Comparable is used for sorting elements in a collection while Comparator is used for custom sorting.

• Example: Stri...read more

Concurrent Hash Map is a thread-safe implementation of a hash map.

• It allows multiple threads to access and modify the map concurrently.

• It uses a technique called lock striping to achieve high concurrency.

• It is part of the java.util.concurrent package in Java.

• Example: ConcurrentHashMap in Java.