Ceph Intro and Architectural Overview by Ross Turk

Ceph Intro & Architectural OverviewRoss TurkVP Community, Inktank

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ME ME ME ME ME ME.I made a slide today. It’s all about me.

Ross TurkVP Community, Inktank

[email protected]@rossturk

inktank.com | ceph.com

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CLOUD SERVICES

COMPUTE NETWORK STORAGE

the future of storage™

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HUMAN

COMPUTER TAPE

HUMAN

ROCK

HUMAN

INK

PAPER

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HUMAN

COMPUTER TAPE

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YOUTECHNOLOG

YYOUR DATA

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How Much Store Things All Human History?!writing

paper

computers

distributed storage

cloud computing

gaaaaaaaaahhhh!!!!!!

carving

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HUMAN COMPUTER DISK

DISK

DISK

DISK

DISK

DISK

DISK

HUMAN

HUMAN

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DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMANHUMAN

HUMANHUMAN

HUMAN

HUMANHUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

COMPUTER

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DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

DISK

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMANHUMAN

HUMANHUMAN

HUMAN

HUMANHUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

HUMAN

GIANT SPENDY

COMPUTER

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DISKCOMPUTE

R

HUMAN

HUMAN

HUMAN

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

R

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HUMAN

HUMAN

HUMAN

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

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DISKCOMPUTE

RDISK

COMPUTER

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DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

“STORAGE APPLIANCE”

14Storage ApplianceMichael Moll, Wikipedia / CC BY-SA 2.0

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SUPPORT AND MAINTENANCE

PROPRIETARY SOFTWARE

PROPRIETARY HARDWARE

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

34% of 2012 revenue(5.2 billion dollars)

1.1 billion in R&Dspent in 2012

1.6 million square feetof manufacturing space

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1010100110

1010110011

1001100101

1001101011

1001100111

1001010011

THE CLOUD

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SUPPORT AND MAINTENANCE

PROPRIETARY SOFTWARE

PROPRIETARY HARDWARE

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

STANDARD HARDWARE

DISKCOMPUTE

RDISK

COMPUTER

DISKCOMPUTE

RDISK

COMPUTER

OPEN SOURCE SOFTWARE

ENTERPRISE SUBSCRIPTION

(optional)

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OPEN SOURCE

COMMUNITY-FOCUSED

SCALABLE

NO SINGLE POINT OF FAILURE

SOFTWARE BASEDSELF-

MANAGING

philosophy design

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8 years & 20,000 commits later…

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RADOS

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

LIBRADOS

A library allowingapps to directlyaccess RADOS,with support forC, 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

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RADOS


LIBRADOS


RBD


CEPH FS


RADOSGW



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DISK

FS

DISK DISK

OSD

DISK DISK

OSD OSD OSD OSD

FS FS FSFS btrfsxfsext4

MMM

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M

M

M

HUMAN

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Monitors:• Maintain cluster

membership and state• Provide consensus for

distributed decision-making• Small, odd number• These do not serve stored

objects to clients

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OSDs:• 10s to 10000s in a cluster• One per disk• (or one per SSD, RAID group…)• Serve stored objects to

clients• Intelligently peer to perform

replication and recovery tasks

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RADOS


LIBRADOS


RBD


CEPH FS


RADOSGW



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LIBRADOS

M

M

M

APP

socket

LLIBRADOS• Provides direct access to

RADOS for applications• C, C++, Python, PHP, Java,

Erlang• Direct access to storage

nodes• No HTTP overhead

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RADOS


LIBRADOS


RBD


CEPH FS


RADOSGW



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M

M

M

LIBRADOS

RADOSGW

APP

socket

REST

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RADOS Gateway:• REST-based object

storage proxy• Uses RADOS to store

objects• API supports buckets,

accounts• Usage accounting for

billing• Compatible with S3 and

Swift applications

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RADOS


LIBRADOS


CEPH FS


RADOSGW



RBD


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M

M

M

VM

LIBRADOS

LIBRBD

VIRTUALIZATION CONTAINER

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LIBRADOS

M

M

M

LIBRBD

CONTAINER

LIBRADOS

LIBRBD

CONTAINERVM

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LIBRADOS

M

M

M

KRBD (KERNEL MODULE)

HOST

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RADOS Block Device:• Storage of disk images in

RADOS• Decouples VMs from host• Images are striped across

the cluster (pool)• Snapshots• Copy-on-write clones• Support in:• Mainline Linux Kernel

(2.6.39+)• Qemu/KVM, native Xen

coming soon• OpenStack, CloudStack,

Nebula, Proxmox

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RADOS


LIBRADOS


RBD


CEPH FS


RADOSGW



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M

M

M

CLIENT

0110

datametadata

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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

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What Makes Ceph Unique?Part one: CRUSH

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APP??

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

43How Long Did It Take You To Find Your Keys This Morning?azmeen, Flickr / CC BY 2.0

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APP

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

45Dear Diary: Today I Put My Keys on the Kitchen CounterBarnaby, Flickr / CC BY 2.0

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APP

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

DC

A-G

H-N

O-T

U-Z

F*

47I Always Put My Keys on the Hook By the Doorvitamindave, Flickr / CC BY 2.0

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HOW DO YOUFIND YOUR KEYS

WHEN YOUR HOUSEIS

INFINITELY BIGAND

ALWAYS CHANGING?

49The Answer: CRUSH!!!!!pasukaru76, Flickr / CC SA 2.0

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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)

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10 10 01 01 10 10 01 11 01 10

10 10 01 01 10 10 01 11 01 10

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CRUSH• Pseudo-random placement

algorithm• Fast calculation, no lookup• Repeatable, deterministic• Statistically uniform

distribution• Stable mapping• Limited data migration on

change• Rule-based configuration• Infrastructure topology aware• Adjustable replication• Weighting

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CLIENT

??

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CLIENT

??

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What Makes Ceph UniquePart two: thin provisioning

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LIBRADOS

M

M

M

VM

LIBRBD

VIRTUALIZATION CONTAINER

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HOW DO YOUSPIN UP

THOUSANDS OF VMsINSTANTLY

ANDEFFICIENTLY?

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144 0 0 0 0

instant copy

= 144

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4144

CLIENT

write

write

write

= 148

write

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4144

CLIENTread

read

read

= 148

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What Makes Ceph Unique?Part three: clustered metadata

65POSIX Filesystem MetadataBarnaby, Flickr / CC BY 2.0

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M

M

M

CLIENT

0110

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M

M

M

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one tree

three metadata servers

??

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DYNAMIC SUBTREE PARTITIONING

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Getting Started With Ceph

Read about the latest version of Ceph.• The latest stuff is always at http://ceph.com/get

Deploy a test cluster using ceph-deploy.• Read the quick-start guide at http://ceph.com/qsg

Deploy a test cluster on the AWS free-tier using Juju.• Read the guide at http://ceph.com/juju

Read the rest of the docs!• Find docs for the latest release at http://ceph.com/docs

Have a working cluster up quickly.

http://ceph.com/get

http://ceph.com/get

http://ceph.com/get

http://ceph.com/qsg

http://ceph.com/qsg

http://ceph.com/juju



http://ceph.com/docs

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Getting Involved With Ceph

Most project discussion happens on the mailing list.• Join or view archives at http://ceph.com/list

IRC is a great place to get help (or help others!)• Find details and historical logs at http://ceph.com/irc

The tracker manages our bugs and feature requests.• Register and start looking around at

http://ceph.com/tracker

Doc updates and suggestions are always welcome.• Learn how to contribute docs at http://ceph.com

/docwriting

Help build the best storage system around!

http://ceph.com/list

http://ceph.com/irc

http://ceph.com/tracker

http://ceph.com/docwriting



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Ceph Cuttlefish (v0.61.x)

1. New ceph-deploy provisioning tool2. New Chef cookbooks3. Fully-tested packages for RHEL (in EPEL)4. RGW authentication management API5. RADOS pool quotas6. New ceph df7. RBD incremental snapshots

Best Ceph ever.

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Questions?

Ross TurkVP Community, Inktank

[email protected]@rossturk

inktank.com | ceph.com

Ceph Intro and Architectural Overview by Ross Turk

Technology

distributed blockdevice

distributed object store

linuxkernel client andsupport

phprbda reliable

radosa reliable

support forc

swiftapp app hostvm

directlyaccess rados