* High throughput, low latency, cross process, persisted key value store. * Supports very high update rates by only replicating the latest value. * Off heap data storage, with micro second latency. * Designed to be used in Java, in a pause less, garbage free manner. * Easy to adopt and open source based on the ConcurrentHashMap. * Better utilizes your existing hardware by offering vertical scalability. * UDP support for high fan out. * TCP connectivity. * Concurrent writers on one machine using one copy in memory. * Concurrent multi-master writers across machines, with a reconciliation process. * Multiple readers with TCP and UDP replication. * Resilient writes (if a process dies, the last write is not lost.) * Entirely embedded, you don’t need any additional processes.

* Ordered-map interface (keys are always sorted; range lookups are supported) * Fully-transactional, full ACID semantics with MVCC * Reader/writer transactions (readers don’t block writers; writers don’t block readers) * Fully serialized writers (writes are always deadlock-free) * Extremely cheap read transactions, which can be performed using no mallocs or any other blocking calls * Multi-thread and multi-process concurrency supported; environments may be opened by multiple processes on the same host * Multiple sub-databases may be created with transactions covering all sub-databases * Memory-mapped, allowing for zero-copy lookup and iteration * Maintenance-free (no external process or background cleanup or compaction required) * Crash-proof (no logs or crash recovery procedures required) * No application-level caching (LMDB fully exploits the operating system’s buffer cache) * 32KB of object code and 6KLOC of C