Biplob Debnath

Mohamed Khalefa

Alex Marchenko

Mohamed Mokbel

David Lilja

Enhanced Performance Scenarios Using

DBMS+OSD

Outline

! Overview of OSD

! Overview of SUN Solaris OSD Implementation

! Overview of DBMS Storage Manager

! Why DBMS + OSD?

! Overview of MySQL Architecture

! Integration Detail

! Current Status

2

Object-based Storage Device (OSD)

Object

! An object is a logical unit– File-like access methods

– Attributes describes the characteristics

– Security policies authorizes access

– Variable size and can store any type of data

– Application can decide what should go into object

– Dynamically shrink and grow4

Object Hierarchy

! The Root object: The OSD itself

! Partition object: Containers for user objects and collections that share

common security and space management characteristics, such as

quotas and keys

! User object: Created by SCSI commands from the application or client

! Collection objects: Index over user objects

5

OSD T10 Commands

6

Traditional File System and OSD

7

A Pictorial View

8

OSD Vs Block-Based Storage Devices

Main Functions Provided OSD

! Data Storage

! Intelligent Layout and Caching

! Metadata Management

! Security

SUN OSD Implementation

11

Database Storage Manger

! The interface between

database systems and disk

storage is in terms of disk

pages (blocks) of

predetermined size (e.g., 8K,

16K, or 32K)

! The data layout on disk is the

N-ary storage model (NSM)

where full records are stored

consecutively within the disk

page.

New Applications

! Peta-scale data size– Data administration becomes challenging

! High-dimensional tables (e.g., 500 attributes in asingle table is common)– NSM data layout is completely inefficient

! A radical change in the query workload as manyqueries ask only about very small part of the table(e.g., decision support queries)– Need a radical change in the data layout

OSD + DBMS : Why?

! Over the last three decades annually

– CPU speed has increased by 60%

– while magnetic disks access time improved by 8%

! Caching + Prefetching is used to reduce this gap

! Block-based devices does not have co-relations knowledge among

the stored blocks

! OSD has explicit block co-relations knowledge

– Very useful to make caching + prefetching decisions

! DBMS query optimizer can specify the access pattern to OSD

through shared attributes

– Nested-loop join, SORT, HASH

! Faster Log flushing in DBMS

Nested Loop Query

SORT with OSD

MySQL Architecture

17

Some Detail of MySQL Storage Engines

! MySQL provides a layer of abstraction that permits different

storage engines to access their tables using the same API

(handler).

! CREATE Table Table1 ….

– MySQL creates files named Table1.MYD ("MySQL Data"),

Table1.MYI ("MySQL Index"), and Table1.frm ("Format")

! Each file will be mapped to a single object

! Our interest is in:

– File Create

– File READ

– FILE WRITE

18

Current Status

! Our plan

– Modify mysiam storage manager

– Run TPC-H

– Compared OSD and traditional disks

! Integration effort is on going

– OSD

– MySQL

Thank You!

20

Comments / Questions?

References

! http://opensolaris.org/os/project/osd/

! http://developers.sun.com/solaris/articles/osd.html

! http://developers.sun.com/solaris/articles/osd_solaris.html

! http://forge.mysql.com/wiki/MySQL_Internals_Custom_Engine

! SNIA Tutorial: Object-based Storage (OSD) Architecture and

Systems, Eric Riedel, April 2006.

22