Dilip N Simha, Maohua Lu, Tzi-cher chiueh

An Update-Aware Storage System for Low-Locality Up-date-Intensive Workloads

Park Chan-hyun

ASPLOS’12 March 3-7, 2012 London, England, UK.

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MotivationBackground BOSCExperimental MethodologyResults and analysisConclusion

Outline

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I/O access delay• Seek rotational, transferLow-locality, update-intensive disk access workload• Disk buffering, caching, schedulingSimple read/write interfaces are not adequate• Read access has higher priority.• Update requests from many applications

Motivation

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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 functionA 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)

New disk access interface

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Trail Disk Architecture

Background

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Background

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Batching Modifications with Sequen-tial Commit

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B tree B+ tree : file managementPort B+ tree index implementation using TPIE• Lock a leaf node before modifying it• Releases the lock after log update request

BOSC-Based B+ Tree

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Intel 2.4GHz CPU512KB L2 cache4GB memory400MH front-side busTwo Gigabit Ethernet interfaceFive 7200_RPM IBM Deskstar DTLA-307030 disks• 4:data disks• 1:logging disk

Evaluation Methodology

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Performance Improvement

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Sensitivity study

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Read query latency

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Solve problems of conventional storage system• An update-aware disk access interface• Efficient batched processing strategy

Deliver good performance with same durability guarantee

Conclusion