HeteroDrive: Reshaping the Storage Access Pattern of OLTP Workload Using SSD

The on-line transaction processing (OLTP) workload is known to produce intense random accesses with high ratio of write. Coping with the random access pattern has been a challenging issue to the underlying storage system. Although SSDs are considered as a breakthrough in storage systems, their random write performance still falls far behind the sequential performance. In this paper, we propose a hybrid storage architecture, HeteroDrive. HeteroDrive actively reshapes random writes to sequential writes. Random writes are routed to SSD and written sequentially. The large capacity of SSD is used as a cache while the contents are flushed to HDD sequentially. According to our evaluation, HeteroDrive improves the transactions per second (TPS) by up to 201 %.