Where is the data stored by ZooKeeper?

ZooKeeper’s data is stored in memory and is persisted to transaction logs on disk. ZooKeeper uses snapshot files and transaction logs to ensure data persistence and consistency. When ZooKeeper starts up, it recovers data from the most recent snapshot file and transaction logs, then continues processing client requests in memory. Therefore, ZooKeeper’s data is stored in memory but also persisted to disk to ensure data persistence.