Alibaba is working on development and deployment of Alibaba Open Channel (AOC) SSDs to address the challenges on the storage devices in today's hyper-scale data centers. Increasing proliferation of Artificial Intelligence, E-commerce, Internet-of-Things, Big Data and Cloud applications is leading to highly diversified workloads and usage cases. These applications can have drastically different I/O patterns, and performance/Quality-of-Service (QoS) targets. Traditional storage architecture is designed around standardized hardware that provides generic block I/O interface, thus has the advantages of portability and backward compatibility. However, it is very challenging for the traditional storage architecture to meet the specific requirements with various usage models. To address this gap, Alibaba is focused on the development and deployment of open channel SSDs since from 2017. Open channel provides the capability of software/hardware co-optimization and storage stack customization based on the applications. In this work, we present our progress towards the large scale deployment of open channel SSDs in hyper-scale data centers. We have defined the Alibaba Open channel (AOC) SSD spec, and built the open channel SSD platform with our industry partners. On top of this platform, we develop the multi-stream capability to achieve reduced write amplification and boosted performance with a simplified Flash-Translation-Layer implementation owing to the co-optimization with the application. We also develop the multiple physical partitions feature with open channel SSDs to achieve the very low read latency in mixed read/write workload through the separation of read and write in search applications.
