We’re committed to providing cutting-edge tools that empower developers and businesses to optimize their applications. One such powerful tool is Redis—an open source, in-memory data structure store that serves as a database, cache, and message broker, ensuring your web applications run smoother and faster than ever.

What is Redis?

Redis—short for REmote DIctionary Server—is a versatile data store designed for speed. By keeping data in memory, Redis offers lightning-fast access to data structures such as:

• Strings
• Hashes
• Lists
• Sets & Sorted Sets (with range queries)
• Bitmaps & HyperLogLogs
• Geospatial Indexes (with radius queries)
• Streams

With support for atomic operations, Redis allows you to effortlessly append to strings, increment values, push elements onto lists, compute set intersections, and more—all with minimal delay.

Key Features of Redis

• High Performance: Operates entirely in memory for rapid data retrieval.
• Versatile Data Structures: Offers a wide range of data types to suit any application.
• Persistence Options: Choose between periodic snapshots (RDB), command logging, or disabling persistence entirely for use purely as a cache.
• Replication & High Availability: Features built-in replication and automatic partitioning via Redis Cluster, along with Redis Sentinel for high availability.
• Advanced Operations: Supports transactions, Lua scripting, and LRU eviction for efficient memory management.
• Broad Language Support: Integrates seamlessly with languages including C, C++, Java, Python, Ruby, PHP, Node.js, and many more.

How Redis Works

Redis achieves top performance by maintaining an in-memory dataset. Depending on your needs, you can persist data by:

• Dumping snapshots to disk at set intervals, or
• Appending commands to a disk-based log.

For applications where data persistence is non-critical, you can opt to run Redis solely as a high-performance cache. With asynchronous replication and fast non-blocking synchronization, Redis ensures that even during network splits, your data remains accessible and consistent.

Memory Management and Configuration

Memory usage is a crucial factor when working with Redis:

• Empty Instance: ~3 MB of memory.
• 1 Million Small Keys: Approximately 85 MB.
• 1 Million Keys (Hashes with 5 fields each): Around 160 MB.

Each Redis instance on Linespace comes with 16 MB of allocated memory by default. To manage memory effectively, you can set a maximum memory limit using the maxmemory configuration option. When this limit is reached, Redis can either return errors for new write commands or automatically evict keys, ensuring stability even under heavy load.

Common Use Cases for Redis

1. Session Cache:
   Store session tokens with persistence, ensuring users don’t lose their shopping carts or login sessions even if the server restarts.
   
2. Full Page Cache (FPC):
   Accelerate page load times by caching entire HTML pages. Popular platforms like Magento and WordPress have dedicated plugins that integrate Redis for FPC, maintaining speed and consistency.
   
3. Message Queues:
   Utilize Redis for managing queues through native push/pop operations on lists, making it ideal for background job processing and real-time messaging.
   
4. Leaderboards and Counting:
   Leverage Redis’ atomic increment/decrement operations and sorted sets for real-time leaderboards, counters, and other dynamic ranking systems.
   
5. Pub/Sub Messaging:
   Redis’ publish/subscribe functionality supports real-time communication, making it perfect for live notifications, chat applications, and more.

Enabling Redis on Linespace

Activating Redis on your Linespace account is simple:

1. Enable the Redis Extension:
   Go to Advanced → PHP Settings → Edit php.ini and switch on Redis.
   
2. Instance Requirements:
   Ensure your plan includes Redis instances. If additional instances are needed, upgrade via the Add/Upgrade service(s) section in your hosting control panel.
   
3. Connection Details:
   On Linespace, Redis operates over a socket instead of a traditional port. Use the following configuration:
   – Redis Hostname (IP): unix:///home/sys/redis.sock
   – Redis Port: 0

Example configuration snippet:

env_variables:
REDISHOST: 'unix:///home/sys/redis.sock'
REDISPORT: '0'

Redis is a robust, high-performance tool that brings a wealth of features to your web applications. Whether you’re looking to improve session handling, speed up page loads with full page caching, manage queues, or implement real-time messaging, Redis on Linespace offers the flexibility and performance you need. Empower your applications with Redis and experience the benefits of reduced server load, improved scalability, and a superior user experience.

Get started with Redis on Linespace today and take your application performance to the next level!