DiStash: A Disaggregated Multi-Stash Transactional Key-Value Store
For developers of distributed applications, DiStash provides a unified transactional interface across heterogeneous storage pools, but it is an incremental extension of existing KV store technology.
DiStash is a disaggregated transactional key-value store that enables transactions across multiple stash types (DRAM, SSD, HDD, NVM), simplifying application logic by preventing race conditions and data loss. It extends FoundationDB and is evaluated with microbenchmarks and eBay's production workload.
A stash is a storage medium such as Dynamic Random Access Memory (DRAM), Solid State Disk (SSD), Hard Disk Drive (HDD), or Non-Volatile Memory (NVM). This paper presents a disaggregated transactional key-value (KV) store, DiStash, that governs KVs cross pools of stash types. It enables an application to use a single transaction to read and write different copies of one or more key-value pair across the different pools of stashes. It simplifies the application logic by (a) preventing undesirable race conditions that may cause copies of data across different stash pools to reflect different values and/or (b) failures that may result in loss of key-value pairs. A configuration of DiStash may use a pool of stashes as either ephemeral or durable storage. The application dictates whether the content of its participating stashes are inclusive (replicated) or exclusive (tiered). We implement a DiStash by extending FoundationDB. We quantify the tradeoffs with its design decisions using microbenchmarks and eBay's production workload. We open source our implementation at https://github.com/ebay-USC/DiStash.