Tachyon is a memory-centric storage system that provides reliable data sharing across different cluster frameworks and jobs at memory speeds. It uses a lineage-based approach to track the sequence of jobs and tasks that create output files to enable fault tolerance through recomputation rather than replication. Tachyon consists of a lineage layer to capture metadata and deliver high throughput I/O, and a persistence layer that takes asynchronous checkpoints of hot files to bound recomputation costs following failures while avoiding impacting system performance. Evaluation results showed Tachyon was over 100x faster than disk-based systems and reduced network traffic by up to 50% while keeping recomputation overhead below 1.6%.