Single-Machine Key-Value Store with Filesystem Spill

Requirements Functional: Support get(key) -> value, put(key, value), and delete(key). The store may contain as many as 1 billion active keys, with values on the order of megabytes each. Data must survive process restarts. Constraints: The filesystem supports file creation, file removal, and append-only file writes. A single file has a fixed upper bound on size, such as 1 GB. The system must use fewer than 100k files in total. Available RAM is insufficient for retaining every…