Redis is an open source, in-memory data structure store, used as a database, cache and message broker. It supports data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs, geospatial indexes with radius queries and streams. Redis has built-in replication, Lua scripting, LRU eviction, transactions and different levels of on-disk persistence, and provides high availability via Redis Sentinel and automatic partitioning with Redis Cluster. The OpenVMS port of Redis 4.0.0 can be used with Alpha and Integrity servers. It includes all in-memory/caching functionality, Lua scripting, and publish/subscribe functionality. Language-agnostic API makes it straightforward to develop applications using 3GL languages such as COBOL, Pascal, and FORTRAN. It also has a PHP extension. Currently, the OpenVMS port of Redis uses 32-bit pointers which limits maximum cache size to around 980MB. Future releases will use 64-bit pointers.


Redis offers the following features:

  • Networked, in-memory, persistent, journaled, key-value data store.
  • Can be used as a database, cache, and message broker
  • Typically holds the entire dataset in memory
  • Very fast
  • Supports various data structures:
    • Strings
    • Hashes
    • Lists and sets
    • Sorted sets with range queries
    • Bitmaps
    • Geospatial indexes with radius queries
  • Supports various high-level atomic server-side operations:
    • Intersection, union, and difference between sets
    • Sorting of lists, sets, and sorted sets
  • Built-in master/slave replication facilities (redundancy)
  • Lua scripting
  • LRU eviction of cache entries
  • Transactions and different levels of on-disk persistence; snapshotting, journaling
  • High availability and clustering via extensions
  • Bindings for most programming languages: C/C++, .NET, Erlang, Java, JavaScript, Lua, Perl, PHP, Python, Ruby, etc.

Latest Version