Dilip N Simha, Maohua Lu, Tzi-cher chiueh Park Chanhyun ASPLOS’12 March 3-7, 2012 London, England, UK.

Motivation Background BOSC Experimental Methodology Results and analysis Conclusion Outline 2

I/O access delay Seek rotational, transfer Low-locality, update-intensive disk access workload Disk buffering, caching, scheduling Simple read/write interfaces are not adequate Read access has higher priority. Update requests from many applications 3 Motivation

Conventional disk access interface Read -> modify -> write Read(target_block_addr, dest_buf_addr) Write(target_block_addr, src_buf_addr) Allow applications of a storage system Disk access request as an update. Associate with an update request, a callback function A new storage system architecture : BOSC Batching mOdifications with Sequential Commit Between storage applications and hardware storage system Modify(target_block_addr, ptr_modification, ptr_commit_function) 4 New disk access interface

Trail Disk Architecture 5 Background

6

7 Batching Modifications with Sequential Commit

B tree B+ tree : file management Port B+ tree index implementation using TPIE Lock a leaf node before modifying it Releases the lock after log update request 8 BOSC-Based B+ Tree

Intel 2.4GHz CPU 512KB L2 cache 4GB memory 400MH front-side bus Two Gigabit Ethernet interface Five 7200_RPM IBM Deskstar DTLA disks 4:data disks 1:logging disk 9 Evaluation Methodology

10 Performance Improvement

11 Sensitivity study

12 Read query latency

Solve problems of conventional storage system An update-aware disk access interface Efficient batched processing strategy Deliver good performance with same durability guarantee 13 Conclusion