vBACD July 2012 - Scaling Storage with Ceph

SCALING STORAGE WITH CEPH

Ross Turk, Inktank

RADOS A reliable, autonomous, distributed object store comprised of self-healing, self-managing, intelligent storage nodes

LIBRADOS A library allowing apps to directly access RADOS, with support for C, C++, Java, Python, Ruby, and PHP

RBD A reliable and fully-distributed block device, with a Linux kernel client and a QEMU/KVM driver

CEPH FS A POSIX-compliant distributed file system, with a Linux kernel client and support for FUSE

RADOSGW A bucket-based REST gateway, compatible with S3 and Swift

APP APP HOST/VM CLIENT

IN THE BEGINNING Magic Madzik, Flickr / CC BY 2.0

EARLY INFORMATION STORAGE Chico.Ferreira, Flickr / CC BY 2.0

WRITING > CAVE PAINTINGS kevingessner, Flickr / CC BY-SA 2.0

x1000

== x1

PEOPLE BEGIN WRITING A LOT Moyan_Brenn, Flickr / CC BY-ND 2.0

WRITING IS T IME-‐CONSUMING trekkyandy, Flickr / CC BY 2.0

THE INDUSTRIALIZATION OF WRITING FateDenied, Flickr / CC BY 2.0

x1000

== x1

+ magnet = tape magnetic tape

STORAGE BECOMES MECHANICAL Erik Pitti, Wikipedia / CC BY-ND 2.0

HUMAN COMPUTER TAPE

HUMAN ROCK

HUMAN

INK

PAPER

COMPUTERS NEED PEOPLE TO WORK USDAgov, Flickr / CC BY 2.0

HUMAN COMPUTER TAPE

11101011 10110110 10110101 10101001 00100100 01001001 10100100 10100101 01011010 01101010 10101010 10101010 01010110 01010011

==

THROUGHPUT BECOMES IMPORTANT Zane Luke, Flickr / CC BY-ND 2.0

LAZ0R B3AMS CHANGE EVERYTHING!! Jeff Kubina, Flickr / CC-BY-SA 2.0

HARD DRIVES ARE TOTALLY BETTER

amazing spinny hard drives sucky stupid tape slow

EVERYTHING GETS MESSY Rob!, Flickr / CC BY 2.0

000

aa

ac ab

ba

111010

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dc

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da 000

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010 011 db

owner: rturk created: aug12

last viewed: aug17 size: 42025 perms: 644 11101011 10110110 10110101

10101001 00100100 01001001 10100100 10100101 01011010 01101010 10101010 10101010

file

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WE OUTGROW THE HARD DRIVE Mr. T in DC, Flickr / CC BY 2.0

HUMAN COMPUTER DISK

DISK

DISK

DISK

DISK

DISK

DISK

PEOPLE NEED S IMULTANEOUS ACCESS wFourier, Flickr / CC BY 2.0

HUMAN COMPUTER DISK

DISK

DISK

DISK

DISK

DISK

DISK

HUMAN

HUMAN

(COMPUTER)

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

HUMAN

HUMAN

HUMAN

HUMAN HUMAN

HUMAN

HUMAN HUMAN

HUMAN HUMAN

HUMAN

HUMAN HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN (actually more like this…)

DISK COMPUTER

HUMAN

HUMAN

HUMAN

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

000

aa

ac ab

ba

111010

bb bc

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010 011 db X

pace: quick driver: frog

license: expired expression: agog

11101011 10110110 10110101 10101001 00100100 01001001 10100100 10100101 01011010 01101010 10101010 10101010

object

DISK COMPUTER

APP

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK

COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

COMPUTER

DISK

DISK

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

COMPUTER

VM

VM

VM

STORAGE THROUGHOUT H ISTORY Time-scale: Roughly logarithmic. Content: Whatever the opposite of “scientific” is.

Writing

Computers

Shared storage

Distributed storage

Cloud computing

Ceph

Painting

DISK COMPUTER

HUMAN

HUMAN

HUMAN

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

DISK COMPUTER

D C

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HUMAN

HUMAN

HUMAN

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D C

D C

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D C

STORAGE APPLIANCES Michael Moll, Wikipedia / CC BY-SA 2.0

6.4 MILL ION SQFT OF FACTORIES Dude94111, Flickr / CC BY 2.0

STORAGE VENDORS HAVE BIG BILLS CarbonNYC, Flickr / CC BY 2.0

STORAGE APPLIANCES ARE EXPENSIVE 401K 2012, Flickr / CC BY-SA 2.0

TECHNOLOGY IS A COMMODITY RaeAllen, Flickr / CC-BY 2.0

COMMODITY PRICES FLUCTUATE

May-07 May-08 May-09 May-10 May-11 May-12

GROWING WITH HARDWARE APPLIANCES

§  First PB §  Proprietary

storage hardware

§  Well-known storage vendor

§  $14 b’zillion

§  Second PB §  Proprietary

storage hardware

§  Same storage vendor

§  Another $14 b’zillion

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

APPLIANCES ARE OLD TECHNOLOGY Paul Keller, Flickr / CC BY 2.0

Source: http://www.cpubenchmark.net/high_end_cpus.html

FLAGSHIP HARDWARE APPLIANCE

Hardware Appliances are Mysterious Black Boxes Abode of Chaos, Flickr / CC BY 2.0

DC

DC

DC

DC

D

C

DC

DC

DC

DC

DC

DC

DC

C++

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DC

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DC

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C

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C++ X

DC

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DC

HUMAN [DEVELOPER]

!!

THE WORLD NEEDS

A STORAGE TECHNOLOGY THAT

SCALES INFINITELY

THE WORLD NEEDS

A STORAGE TECHNOLOGY THAT DOESN’T REQUIRE

AN INDUSTRIAL

MANUFACTURING PROCESS

SAGE WEIL

§  Co-founder of DreamHost

§  Inventor of Ceph

§  CEO of Inktank

OPEN SOURCE

philosophy design

OPEN SOURCE SPREADS IDEAS orchidgalore, Flickr / CC BY 2.0

OPEN SOURCE

COMMUNITY-FOCUSED

philosophy design

WE ARE SMARTER TOGETHER rturk, Linkedin Inmap

CEPH BELONGS TO ALL OF US wackybadger, Flickr / CC BY 2.0

OPEN SOURCE

COMMUNITY-FOCUSED

SCALABLE

philosophy design

CEPH IS BUILT TO SCALE

Too much for a book

Too much for a drive

Too much for a computer

Too much for a room

Ceph

Too much for a cave

OPEN SOURCE

COMMUNITY-FOCUSED

SCALABLE

NO SINGLE POINT OF FAILURE

philosophy design

ARILOMAX CALIFORNICUS aroid, Flickr / CC BY 2.0

THE OCTOPUS (A METAPHOR) I love speaking in metaphors.

single point of failure

highly-available replicated

THE BEEHIVE (ANOTHER METAPHOR) blumenbiene, Flickr / CC BY 2.0

OPEN SOURCE

COMMUNITY-FOCUSED

SCALABLE


SOFTWARE BASED

philosophy design

DC

DC

DC

DC

D

C

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DC

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DC

DC

DC

C++

DC

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DC

DC

D

C

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DC

C++ ✔

OPEN SOURCE

COMMUNITY-FOCUSED

SCALABLE


SOFTWARE BASED

SELF-MANAGING

philosophy design

DISKS = JUST T INY RECORD PLAYERS jon_a_ross, Flickr / CC BY 2.0

D

55 times / day

= D

D D

x 1 MILLION

D D

D D

IT ALL STARTED WITH A DREAM

+

NEW MONTHLY CODE COMMITS

0

100

200

300

400

500

600

700

2004-06 2005-07 2006-07 2007-07 2008-07 2009-07 2010-07 2011-07

CEPH STARTS POPPING UP!

(sorry about all the logo tampering)













DISK

FS

DISK DISK

OSD

DISK DISK

OSD OSD OSD OSD

FS FS FS FS btrfs xfs ext4

M M M

M

M

M

HUMAN

Monitors: §  Maintain cluster map §  Provide consensus for

distributed decision-making

§  Must have an odd number §  These do not serve stored

objects to clients

M

OSDs: §  One per disk

(recommended) §  At least three in a cluster §  Serve stored objects to

clients §  Intelligently peer to perform

replication tasks §  Supports object classes







LIBRADOS

M

M

M

APP

native

L

87

LIBRADOS §  Provides direct access to

RADOS for applications §  C, C++, Python, PHP,

Java §  No HTTP overhead







M

M

M

native

REST

APP

LIBRADOS RADOSGW

LIBRADOS RADOSGW

APP

RADOS Gateway: §  REST-based interface to

RADOS §  Supports buckets,

accounting §  Compatible with S3 and

Swift applications







M

M

M

VM

LIBRADOS LIBRBD

VIRTUALIZATION CONTAINER

LIBRADOS

M

M

M

LIBRBD CONTAINER

LIBRADOS LIBRBD

CONTAINER VM

LIBRADOS

M

M

M

KRBD (KERNEL MODULE) HOST

RADOS Block Device: §  Storage of virtual disks in

RADOS §  Allows decoupling of VMs

and containers §  Live migration!

§  Images are striped across the cluster

§  Boot support in QEMU, KVM, and OpenStack Nova

§  Mount support in the Linux kernel







M

M

M

CLIENT

01 10

data metadata

Metadata Server §  Manages metadata for a

POSIX-compliant shared filesystem §  Directory hierarchy §  File metadata (owner,

timestamps, mode, etc.) §  Stores metadata in RADOS §  Does not serve file data to

clients §  Only required for shared

filesystem

WHAT MAKES CEPH UNIQUE?

HOW DO YOU F IND YOUR KEYS? azmeen, Flickr / CC BY 2.0

APP ??

D C

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APP

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D C

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D C

D C

A-G

H-N

O-T

U-Z

F*

I ALWAYS PUT MY KEYS ON THE HOOK vitamindave, Flickr / CC BY 2.0

APP

D C

D C

D C

D C

D C

D C

D C

D C

D C

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D C

D C

DEAR DIARY: KEYS = IN THE KITCHEN Barnaby, Flickr / CC BY 2.0

HOW DO YOU FIND YOUR KEYS

WHEN YOUR HOUSE IS

INFINITELY BIG AND

ALWAYS CHANGING?

THE ANSWER: CRUSH!! pasukaru76, Flickr / CC SA 2.0

10 10 01 01 10 10 01 11 01 10

10 10 01 01 10 10 01 11 01 10

hash(object name) % num pg

CRUSH(pg, cluster state, rule set)

10 10 01 01 10 10 01 11 01 10

10 10 01 01 10 10 01 11 01 10

CRUSH §  Pseudo-random placement

algorithm §  Ensures even distribution §  Repeatable, deterministic §  Rule-based configuration

§  Replica count §  Infrastructure topology §  Weighting

CLIENT

??

CLIENT

??

LIBRADOS

M

M

M

VM

LIBRBD VIRTUALIZATION CONTAINER

HOW DO YOU SPIN UP

THOUSANDS OF VMs INSTANTLY

AND EFFICIENTLY?

144 0 0 0 0

instant copy

= 144

4 144

CLIENT

write

write

write

= 148

write

4 144

CLIENT read

read

read

= 148

HOW DO YOU MANAGE

DIRECTORY HEIRARCHY WITHOUT

A SINGLE POINT OF FAILURE?

FILESYSTEMS REQUIRE METADATA Barnaby, Flickr / CC BY 2.0

M

M

M

CLIENT

01 10

M

M

M

one tree

three metadata servers

??

DYNAMIC SUBTREE PARTITIONING

AND NOW BACKPEDALING

ALMOST EVERYTHING

WORKS







NEARLY AWESOME

AWESOME AWESOME

AWESOME

AWESOME

LAN SCALE!! *

* OR REALLY REALLY SCARY FAST WAN

CEPH AND CLOUDSTACK tableatny, Flickr / CC BY 2.0

RBD SUPPORT IN CLOUDSTACK

§  Just announced two weeks ago! §  Allows storage of virtual disks inside RADOS

§  Works with KVM only right now §  No volume snapshots yet

§  Requires the latest version of, um, everything §  More information can be found on the mailing list:

§  ceph-devel / incubator-cloudstack-dev: http://article.gmane.org/gmane.comp.file-systems.ceph.devel/7505

QUESTIONS?

Ross Turk VP Community, Inktank

§  [email protected] §  @rossturk

inktank.com | ceph.com

Technology

vBACD July 2012 - Scaling Storage with Ceph