Megha Engineering & Infrastructures Interview Questions and Answers

Microservices communicate through lightweight protocols like HTTP, messaging queues, and RPC.

• Microservices can communicate over HTTP using RESTful APIs.

• Message queues like RabbitMQ or Kafka can be used for asynchronous communication between microservices.

• Remote Procedure Calls (RPC) can be used for synchronous communication between microservices.

• Service discovery mechanisms like Eureka or Consul help microservices locate each other.

• API gateways can be used to manage and secur...read more

Design a scalable system for millions of users

• Use microservices architecture to break down the system into smaller, independent services

• Implement load balancing to distribute traffic evenly across servers

• Utilize caching mechanisms to reduce database load and improve performance

• Use horizontal scaling by adding more servers to handle increased traffic

• Implement monitoring and alerting systems to track system performance and detect issues proactively

Factory pattern creates objects without exposing the instantiation logic, while Abstract Factory pattern provides an interface for creating families of related objects.

• Factory pattern is a creational design pattern that provides a way to create objects without specifying the exact class of object that will be created.

• Abstract Factory pattern is a creational design pattern that provides an interface for creating families of related or dependent objects without specifying their...read more

Kafka deletes messages based on retention policies and compaction

• Kafka deletes messages based on retention policies set at topic level

• Messages can also be deleted through log compaction process

• Retention policies can be based on time or size of messages

Kafka implementation in Spring Boot allows for easy integration of Kafka messaging system in Java applications.

• Use Spring Kafka to configure Kafka properties in Spring Boot application

• Create Kafka producer and consumer beans to send and receive messages

• Use @KafkaListener annotation to listen for messages on specific topics

Structured logs have a predefined format for easy parsing, while unstructured logs do not.

• Structured logs are easier to search, filter, and analyze compared to unstructured logs.

• Unstructured logs can be harder to parse and may require more manual effort to extract useful information.

• Examples of structured logs include JSON or CSV format, while unstructured logs may be plain text or free-form messages.