Redis
Processing billions of operations per second across companies like Twitter, GitHub, Snapchat, and Stack Overflow, Redis is the world's fastest and most widely deployed in-memory data store. Redis 8 unifies previously separate modules into a single distribution: RediSearch for full-text indexing with BM25 scoring and vector similarity search via HNSW and FLAT algorithms, RedisJSON for native JSON document storage with JSONPath queries, RedisTimeSeries for timestamped data with configurable downsampling compaction rules, and RedisBloom for probabilistic data structures including Bloom filters, cuckoo filters, count-min sketches, top-k, and t-digest. The core engine provides strings, lists, sets, sorted sets, hashes, streams, HyperLogLog, bitmaps, bitfields, geospatial indexes, and the new array data structure introduced in Redis 8.8. Pub/Sub delivers lightweight real-time messaging between publishers and subscribers, while Streams provide an append-only log with consumer groups for event sourcing and complex consumption patterns. Redis Cluster distributes data across nodes with automatic sharding using 16,384 hash slots, and Sentinel provides high availability with automatic failover monitoring. Lua scripting and Redis Functions enable server-side computation, and ACL-based security provides granular per-command, per-key access control. Official clients exist for Python, Node.js, Java, Go, .NET, Rust, and PHP. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPLv3 licensed.
DragonflyDB
With over 30,000 GitHub stars and benchmarks showing 25x the throughput of single-threaded Redis, DragonflyDB is a modern in-memory data store that eliminates the need for complex Redis Cluster deployments by fully utilizing every CPU core on a single machine. Its shared-nothing, thread-per-core architecture written in C++ supports over 200 Redis commands and 13 Memcached commands, making it a true drop-in replacement that requires zero application code changes. A single DragonflyDB instance scales vertically from 8GB to 768GB of RAM across up to 64 cores, replacing entire Redis Cluster topologies with one process while maintaining full compatibility with Strings, Hashes, Lists, Sets, Sorted Sets, Streams, JSON, and Bloom Filters. The novel dashtable data structure and cache eviction algorithm achieve higher hit rates than LRU and LFU with zero memory overhead per entry. Forkless point-in-time snapshotting eliminates the memory spikes associated with Redis BGSAVE, while automatic backup scheduling via cron syntax supports both local disk and AWS S3 cloud storage. Primary-replica replication follows the Redis replication protocol up to version 6.2, and Prometheus-compatible metrics at the default port enable Grafana monitoring dashboards out of the box. DragonflyDB also exposes an HTTP admin interface on its main TCP port for operational monitoring. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. BSL 1.1 licensed.