UmaDB is a specialist open-source event store built for dynamic consistency boundaries.

UmaDB supports event-driven architectures where consistency rules can adapt dynamically to business needs, rather than being hardwired into the database.

UmaDB directly implements the independent specification for Dynamic Consistency Boundaries created by Bastian Waidelich, Sara Pellegrini, and Paul Grimshaw.

UmaDB stores events in an append-only sequence, indexed by monotonically increasing gapless positions, and can be tagged for fast, precise filtering.

UmaDB offers:

• High-performance concurrency with non-blocking reads and writes
• Optimistic concurrency control to prevent simultaneous write conflicts
• Dynamic business-rule enforcement via query-driven append conditions
• Real-time subscriptions with seamless catch-up and continuous delivery
• OSI-approved permissive open-source licenses (MIT and Apache License 2.0)

UmaDB makes new events fully durable before acknowledgements are returned to clients.

Please visit the UmaDB website for more information.

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in UmaDB by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.