US Patent 10903981 Log-structured storage systems

Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage devices, for data processing and storage. One of the systems includes a first tier storage device with a first performance characteristic and a second tier storage device with a second performance characteristic inferior to the first performance characteristic. The first tier storage device stores a first data log file that includes first blockchain data generated by a blockchain network. The second tier storage device stores a second data log file that includes second blockchain data generated by the blockchain network at an earlier time than the first blockchain data.