Memcached vs Redis vs guava: What are the differences?

Key Differences between Memcached and Redis and Guava

Memcached and Redis are both popular in-memory data stores that are commonly used for caching and improving the performance of web applications. Guava, on the other hand, is a Java library that provides various utility classes and functions. While all three have caching capabilities, there are some key differences between them.

1. Data Structure Support: Redis and Guava provide more extensive data structure support compared to Memcached. Redis includes data structures such as strings, hashes, lists, sets, and sorted sets, making it more suitable for complex data manipulation. Guava, on the other hand, offers data structures like collections, caching, and functional types that are highly efficient.

2. Persistence: Redis has built-in persistence options, allowing data to be stored on disk and loaded back into memory upon restart. This feature makes Redis more suitable for use cases that require persistence and data durability. Memcached, on the other hand, does not provide built-in persistence and is generally used for caching purposes only. Guava does not offer persistence as it is mainly focused on providing utility functions.

3. Scalability: Redis and Memcached are designed to be highly scalable and can be easily scaled horizontally by adding more servers to the cache cluster. Memcached is a distributed cache that allows data to be spread across multiple nodes, while Redis supports replication and sharding for scalability. Guava, being a Java library, does not provide built-in scalability features and is limited by the resources of a single Java Virtual Machine (JVM).

4. Support for Multiple Programming Languages: Memcached and Redis are both designed to support multiple programming languages and can be accessed from various application frameworks. Redis supports clients for different programming languages, including Java, C++, Python, and more. Guava, being a Java library, is primarily targeted for Java developers and does not have direct support for other programming languages.

5. Cache Eviction Policies: Redis and Guava both provide flexible cache eviction policies, allowing control over how data is evicted from the cache in case it becomes full. Redis offers a variety of eviction options, including LRU (Least Recently Used), LFU (Least Frequently Used), and more. Guava also provides different eviction policies like LRU, LFU, and size-based eviction. Memcached, however, does not provide built-in eviction policies and relies on application logic to manage cache eviction.

6. Additional Features: Redis provides additional features such as pub/sub messaging, transactions, and Lua scripting, making it more suitable for use cases requiring real-time messaging and atomic operations. Guava, being a utility library, offers various additional features like functional programming support, string manipulation utilities, and concurrency primitives.

In Summary, Memcached and Redis are powerful in-memory data stores with key differences in data structure support, persistence, scalability, programming language support, cache eviction policies, and additional features. Guava, on the other hand, is a Java library focused on providing utility classes and functions.