Integrating Cache: Redis Flashcards
What is Redis?
Redis is an open-source, in-memory data structure store used as a database, cache, and message broker.
Why would you use Redis as a cache in a web app?
Redis provides fast read and write operations as an in-memory database, making it an efficient choice for caching frequently accessed data in a web application.
What is Jedis?
Jedis is a Java library for interacting with Redis. It serves as a Redis Java client, allowing Java applications to connect to and use Redis.
How do you connect to a Redis server using Jedis in Java?
You can connect to a Redis server using Jedis by creating a Jedis instance and providing the server host and port. For example:
Jedis jedis = new Jedis(“localhost”, 6379);
What is a cache miss in the context of Redis?
A cache miss occurs when the requested data is not found in the Redis cache. In such cases, the application may need to fetch the data from the source and update the cache.
How can you handle a cache miss in your Java application using Redis?
In case of a cache miss, fetch the data from the source (e.g., a database), update the Redis cache with the new data, and then return the data to the application.
What are some benefits of using Redis as a cache?
Benefits include high-performance caching due to in-memory storage, support for various data structures, and features like expiration time for cached data.
What is multi-model Redis?
Multi-model Redis refers to the ability of Redis to support multiple data models within a single database, including key-value pairs, strings, hashes, lists, sets, and more.
Name a few data structures supported by Redis.
Redis supports data structures such as strings, hashes, lists, sets, sorted sets, bitmaps, and hyperloglogs.
How is data stored in Redis?
Data in Redis is stored as key-value pairs, where each key is associated with a specific data structure or type.
What is a use case for Redis strings?
Redis strings are commonly used to store textual or binary data and are versatile for various purposes, such as caching and counters.
In Redis, what is a hash?
A hash in Redis is a data structure that maps fields to values, allowing the storage of key-value pairs within a single key.
Name a scenario where Redis sets are useful.
Redis sets are useful in scenarios where you need to store and perform operations on an unordered collection of unique elements.
What is a sorted set in Redis?
A sorted set in Redis is similar to a regular set but assigns a score to each element. It allows for fast retrieval of elements based on their scores.
How can you extend the functionality of Redis using modules?
Redis modules allow developers to add new functionalities and data types to Redis. They can be loaded dynamically to enhance Redis capabilities.
Give an example of a popular Redis module.
Redisearch is a popular Redis module that provides full-text indexing and search capabilities.
What is the primary advantage of using Redis Sentinel?
Redis Sentinel provides high availability by monitoring Redis instances and automatically handling failover when a master node goes down.
Describe the pub/sub mechanism in Redis.
Redis pub/sub allows message broadcasting. Publishers send messages to channels, and subscribers receive messages from the channels they are interested in.
How does Redis Cluster work?
Redis Cluster is a distributed implementation that uses sharding and automatic partitioning to provide high availability and scalability.
What is the purpose of Redis Lua scripting?
Redis Lua scripting allows the execution of atomic operations on the server, reducing the need for multiple round trips to the server.
Explain the role of a Redis client.
A Redis client is a software component that connects to a Redis server, sends commands, and processes the responses.
What is Redis Enterprise Software?
Redis Enterprise Software is a commercial offering that provides enhanced features and enterprise-level support for Redis, including high availability, sharding, and Redis on Flash.
Explain the key features of Redis Enterprise Cloud.
Redis Enterprise Cloud is a fully managed Redis service in the cloud, offering automatic scaling, high availability, and seamless integration with cloud platforms.
What is the role of Redis Enterprise Software in achieving high availability?
Redis Enterprise Software ensures high availability through features such as automatic partitioning, replication, and failover.
How does Redis Enterprise Cloud handle automatic scaling?
Redis Enterprise Cloud automatically scales by adding or removing nodes based on the workload, ensuring optimal performance and resource utilization.
Describe the benefits of using Redis on Flash with Redis Enterprise Software.
Redis on Flash allows cost-effective storage of large datasets by utilizing Flash storage while maintaining high performance for frequently accessed data.
What is the significance of Active-Active Geo-Distribution in Redis Enterprise?
Active-Active Geo-Distribution enables the deployment of Redis databases across multiple geographical regions, ensuring low-latency access for users globally.
How does Redis Enterprise Software handle data durability?
Redis Enterprise Software ensures data durability through features like persistent storage options, snapshots, and replication across multiple nodes.
What are some security features provided by Redis Enterprise Cloud?
Redis Enterprise Cloud offers features such as Virtual Private Cloud (VPC) peering, encryption at rest, and network isolation to enhance security.
Explain the role of the Redis Enterprise Manager in Redis Enterprise deployments.
The Redis Enterprise Manager provides a centralized interface for managing and monitoring Redis Enterprise deployments, including nodes, databases, and configurations.
In what scenarios might an organization choose Redis Enterprise Cloud over Redis Enterprise Software?
Organizations might opt for Redis Enterprise Cloud for its ease of use, automatic scaling, and fully managed nature, while Redis Enterprise Software is chosen for on-premises deployments with specific customization requirements.
What is a pub-sub model, and how is it implemented in Redis?
The publish-subscribe (pub-sub) model allows communication between multiple entities. In Redis, publishers send messages to channels, and subscribers receive messages from channels they are interested in.
How can Redis be utilized for real-time analytics?
Redis’ fast read and write operations make it suitable for real-time analytics. Applications can store and process real-time data, such as user interactions, in Redis
