Senior DevOps Engineer - Autonomous Database

Oracle

Simulate a multithreaded producer-consumer problem using Java threads and semaphores. Implement a producer that generates items and adds them to a shared buffer, and a consumer that retrieves and processes items from the same buffer. Synchronize access to the buffer using semaphores to prevent race conditions and ensure that the producer doesn't add items to a full buffer and the consumer doesn't try to retrieve items from an empty buffer. Specifically: Define a shared buffer: This could be an ArrayList or any other suitable data structure with a fixed capacity. Implement the Producer: The producer should generate a series of items (e.g., integers) and attempt to add them to the buffer. Before adding an item, it must acquire a semaphore that represents available space in the buffer. If no space is available, the producer should wait. After adding an item, it should release a semaphore that represents available items in the buffer. Implement the Consumer: The consumer should attempt to retrieve and process items from the buffer. Before retrieving an item, it must acquire a semaphore that represents available items in the buffer. If no items are available, the consumer should wait. After retrieving an item, it should release a semaphore that represents available space in the buffer. Synchronization: Use semaphores to handle synchronization. One semaphore should track the number of empty slots in the buffer, and another should track the number of filled slots. Example Scenario: Create a buffer with a capacity of 5. Have the producer generate 10 items and the consumer consume 10 items. Print messages indicating when the producer adds an item and when the consumer consumes an item. Ensure that the producer and consumer run concurrently and that no items are lost or duplicated. Your solution should demonstrate: Proper use of Java threads. Correct semaphore usage for synchronization. Prevention of race conditions. Handling of full and empty buffer conditions.

Oracle

Let's design a URL shortening service like bit.ly. Consider the following: Functional Requirements: The service should accept a long URL and generate a unique short URL. Users should be able to access the original URL by visiting the shortened URL. The service should track click statistics for each shortened URL. Non-Functional Requirements: The service should be highly available and scalable to handle a large number of URL shortening and redirection requests. Shortened URLs should be generated quickly. The system should be fault-tolerant. Considerations: How would you handle URL collisions (when the same short URL is generated for different long URLs)? How would you design the data storage? How would you optimize the system for read-heavy traffic (redirections)? How would you implement analytics and track clicks? Explain the architectural components, data model, algorithms, and scaling strategies you would use to build such a system. Provide specific examples for URL encoding and decoding. For example, how would you encode https://www.example.com/very/long/url/path into something like bit.ly/xyz123?

Oracle

Describe a time you had to work with a difficult person. What was the situation?** For example, were you working on a team project with a classmate who wasn't pulling their weight? Or perhaps you had a colleague who was constantly negative and bringing down the morale of the team? Who was the difficult person, and what made them difficult?** Was it a personality clash? Did they have different work styles? Were they simply uncooperative or unwilling to compromise? Be specific about their behaviors and how they impacted you and the team. What actions did you take to address the situation?** Did you try to communicate with the person directly? Did you involve a supervisor or mediator? Did you try to find common ground or compromise on solutions? What was the outcome?** Were you able to resolve the conflict and improve the working relationship? If not, what were the consequences? What did you learn from the experience, and how would you handle a similar situation differently in the future?