11 karma · joined August 11, 2014
tl;dr we launched Memgraph 2.0 with a strong focus on streaming graph data, with connectors to streaming data sources, faster graph computation engine, and incremental execution of graph algorithms as the new data comes in.
We made the entire thing source-available under the Business Source License (BSL) which converts to Apache 2.0 four years after each release. We were heavily inspired by other startup companies in the DB space like Cockroach Labs with our licensing. Check it out on GitHub!
All editions of Memgraph persist data to the disk via write-ahead logging (WAL) and periodic snapshots for log compaction so even though Memgraph is designed to be in-memory first, data is always backed up to disk. If you enable asynchronous (periodic fsync) WAL, you can trade off a small window of durability for better performance.
Before 1.0, Memgraph leveraged the RAFT consensus algorithm for HA which worked great but had some performance implications. Based on feedback from our users and customers, we have decided to switch our HA implementation to the streaming replication model (similar to PostgreSQL) with automatic failover.