BOF: Bittern Disk Cache

Session information has not yet been published for this event.

60 Minute BoF
Scheduled: Thursday, August 20, 2015 from 5:00 – 6:00pm in Metropolitan B

One Line Summary

Bittern Disk Cache: replacing Hardware RAID with Persistent Memory and software RAID stack


In this presentation, Fio Cattaneo, will talk about how Twitter Cache takes advantage of Persistent Memory technology (NVDIMM and PCIe-NVRAM) and software RAID to replace the functionality of HW RAID. Its main advantages are lower costs, the use of commodity hardware and open source stack versus proprietary HW RAID solutions. Twitter Cache is tuned towards optimizing the use of persistent memory which is smaller but faster than SSD caching solutions. Eviction algorithms are tuned towards a write buffer to best utilize the smaller size. Cache access uses a low overhead API as opposed to block store. Metadata is kept in memory for fast access. Because of its low latency, it also allows for caching of SSD storage. Twitter Cache is being actively developed and tested on Twitter workloads.

Bittern was already presented at Linuxcon 2014 . Bittern is now being deployed within Twitter for transactional workloads.


storage, SSD, cache, nvdimm, bittern, disk cache, nvme, disk


  • Biography

    Fio Cattaneo has been working in the industry for 25 years and his main interests are in kernels, operating systems and distributed systems. His first kernel work was at Olivetti S.p.A., help porting BSD4.2 on a Motorola architecture, and subsequently develop multiprocessor support in the early days of SMP technology. More recently he worked on distributed systems and storage at Pyramid Technology and Bluearc. He worked at Microsoft in the clustering group, and at Amazon AWS on distributed systems and storage technologies. He joined Twitter in early 2013 and works for the OS Team on the Twitter Cache project.