What is BASE?
Also known as: Basically Available, Soft state, Eventual consistency
BASE is a design philosophy for distributed databases that prioritizes availability and partition tolerance over immediate consistency, making it a looser alternative to ACID in NoSQL systems.
BASE stands for Basically Available, Soft state, Eventual consistency. It is a set of principles for designing distributed databases, especially NoSQL systems, that relax the strict consistency guarantees of ACID (Atomicity, Consistency, Isolation, Durability) in exchange for higher availability and scalability. The term was coined by Eric Brewer in the late 1990s as a counterpart to ACID, reflecting the trade-offs described in the CAP theorem.
Under BASE, a system remains "Basically Available" meaning it responds to every request, even if that response may be a stale or incomplete result. "Soft state" means the system's state can change over time without input, because nodes may diverge and later converge. "Eventual consistency" guarantees that, given enough time without new updates, all replicas will converge to the same value. This model allows writes to proceed even when network partitions occur, at the cost of temporary inconsistency.
BASE is commonly used in distributed key-value stores, document databases, and other NoSQL systems such as Amazon Dynamo, Apache Cassandra, and Riak. It is appropriate for applications where availability and partition tolerance matter more than immediate consistency, for example social media feeds, shopping cart services, and content caching layers. Developers must design application logic to handle stale reads and resolve conflicts, often using techniques like last-write-wins or version vectors.
Key facts
- BASE was coined by Eric Brewer as a counterpart to ACID for distributed systems.
- It relaxes consistency guarantees to achieve higher availability and partition tolerance.
- The three pillars are Basically Available, Soft state, and Eventual consistency.
- BASE systems often use conflict resolution strategies like last-write-wins or version vectors.
- It is a practical embodiment of the CAP theorem trade-offs, favoring AP over CP.
How it works in practice
Related terms
References
More in Databases
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