How does Cassandra ensure data consistency?
Cassandra ensures data consistency through various methods:
- Cassandra employs the Quorum consistency level to ensure the consistency of data. When writing or reading data, at least over half of the nodes need to confirm an operation for it to be considered successful. This helps avoid data inconsistencies caused by node failures or network partitions.
- Hinted Handoff: When a node is temporarily unavailable, Cassandra will temporarily store the data that needs to be written to that node on other available nodes. Once the node is back online, the data will be transferred to ensure data integrity.
- Cassandra performs regular checks on data consistency and automatically repairs any inconsistencies that are found when reading data.
- Cassandra uses Anti-Entropy Repair to ensure data consistency, which is an automated repair mechanism that detects and fixes any inconsistencies by comparing data between different nodes.
By using the above methods, Cassandra can effectively ensure data consistency and guarantee the reliability and stability of data in a distributed environment.