Swift Automated Tiering (Swift Hackathon Bristol)

Copyright©2015 NTT corp. All Rights Reserved.

Swift Automated Tiering

Kazuhiro MIYAHARA [IRC: m_kazuhiro] [email protected] NTT Software Innovation Center

Copyright(c)2009-2016 NTT CORPORATION. All Rights Reserved.

2 Copyright©2015 NTT corp. All Rights Reserved.

Goal

• Discuss and get agreement for a particular design for our “Automated-Tiering” implementation. (Especially focus on moving and linking objects among tiers)

Note : This slide will show you overview of our implementation.

Note : For more detail, please see the gerrit code <https://review.openstack.org/#/c /287057/>

Agenda

• Background

• Changes of Swift

• Components of Our Proposal

• Overview of Deliverer

• Deliverer’s Process (STEP 1)

• States in STEP 2 ~ 4

• Deliverer’s Process (STEP 2 ~ 4)

• Demo

Goal & Agenda

https://review.openstack.org/#/c/287057/


Our Use Case

Contents (e.g. movies, pictures, music) providing service.

In this service, new contents are requested frequently and gradually becoming less frequently requested.

Our Requirement

Store frequently requested objects into replication policy containers for performance and infrequently requested objects into erasure coding policy containers for capacity efficiency.

Background


Seemingly, containers have variable storage policy objects.

• Objects move among some different storage policy containers automatically.

• Swift ensures transparent access to the automatically moved objects.

Changes of Swift

“a/c”

policy index : 0

“a/c/o2”

Policy index : 1

“a/c/o4”

Policy index : 0

“a/c/o6”

Policy index : 1

“a/c/o1”

Policy index : 0

“a/c/o3”

Policy index : 2

“a/c/o5”

Policy index : 0

Container

Object


Deliverer (daemon) : what I focus on today

• Move objects to the suitable policy container.

Addresser (daemon) : future work

• Search objects whose policy is not suitable and decide their suitable policy.

Components of Our Proposal

addresser deliverer

“.delivery_task”

PUT GET

delivery task object :

Includes an object path “a/c/o” and a storage policy index “N” In the name.

The name means “N” is the suitable policy for “a/c/o”.

Account

Object

Container

…

…

…

…


• Deliverers run on storage nodes (as well as object-replicator).

• 4 steps in Deliverer’s process.

• STEP 1 : GET a list of delivery task objects.

• STEP 2 : COPY each entity object to a suitable policy container.

• STEP 3 : PUT transparent link objects.

• STEP 4 : DELETE extra objects.

Note : STEP 3 and 4 may be skipped.

Overview of Deliverer

deliverer

object-server

node

deliverer

object-server

node

deliverer

object-server

node


GET lists of objects from a special account “.delivery_task”

Deliverer’s process (STEP 1)

deliverer

“.delivery_task”

“12345600”

“2:a1/c1/o1”

“0:a3/c3/o3”

“1:a2/c2/o2”

…

GET .delivery_task/12345600

List of delivery task objects

object name format :

“<storage policy index>:<object path>”

storage policy index : The suitable policy index.

object path : The object path whose policy is not suitable.

Users can transparently access the moved object with this path.

Account

Object

Container

Container names are the hours in Unix time format when the

delivery task objects are created.


2 states of tiered objects

• State A : stored policy = original policy

• State B : stored policy ≠ original policy

States in STEP 2 ~ 4

“a/c_silver”

policy index : 1

policy name : silver

“a/c”

policy index : 0

policy name : gold

“a/c_silver/o”

Policy index : 1

Entity

“a/c”

policy index : 0

policy name : gold

“a/c/o”

Policy index : 0

Entity

State B of a/c/o State A of a/c/o

A SLO manifest object with only one

segment “a/c_silver/o”

original

container

derivative

container The object which an user

PUT first to “a/c/o”

original

policy

derivative

policy

Object

Container

Link object

“a/c/o”

Policy index : 0

Link to “a/c_silver/o”


3 cases in STEP 2 ~ 4.

Case 1 : From the original policy to a derivative policy

(STEP 2 [COPY], STEP 3 [PUT Link])

Case 2 : From a derivative policy to the original policy

(STEP 2 [COPY], STEP 4 [DELETE])

Case 3 : From a derivative policy to another derivative policy

(STEP 2 [COPY], STEP 3 [PUT Link], STEP 4 [DELETE])

Deliverer’s Process (STEP 2 ~ 4)




• STEP 3 : PUT transparent link object.


“a/c_silver”

policy index : 1


after

“a/c”

policy index : 0

policy name : gold

“a/c/o”

Policy index : 0

Entity

“a/c_silver/o”

Policy index : 1

Entity

“a/c_silver”

policy index : 1


before

“a/c”

policy index : 0

policy name : gold

“a/c/o”

Policy index : 0

Entity

Object

Container

Link object






“a/c_silver”

policy index : 1


before

“a/c”

policy index : 0

policy name : gold

“a/c/o”

Policy index : 0

Entity

“a/c_silver/o”

Policy index : 1

Entity

“a/c_silver”

policy index : 1


after

“a/c”

policy index : 0

policy name : gold

“a/c_silver/o”

Policy index : 1

Entity

“a/c/o”

Policy index : 0


Object

Container

Link object






“a/c_silver”

policy index : 1


before

“a/c”

policy index : 0

policy name : gold

“a/c_silver/o”

Policy index : 1

Entity

“a/c_silver”

policy index : 1


after

“a/c”

policy index : 0

policy name : gold

“a/c/o”

Policy index : 0

Entity

“a/c_silver/o”

Policy index : 1

Entity

Object

Container

Link object

“a/c/o”

Policy index : 0







“a/c_silver”

policy index : 1


before

“a/c”

policy index : 0

policy name : gold

“a/c/o”

Policy index : 0

Entity

“a/c_silver/o”

Policy index : 1

Entity

“a/c_silver”

policy index : 1


after

“a/c”

policy index : 0

policy name : gold

“a/c/o”

Policy index : 0

Entity

Object

Container

Link object







before “a/c”

policy index : 0

policy name : gold

“a/c_bronze”

policy index : 2

policy name : bronze

“a/c_silver”

policy index : 1


“a/c_silver/o”

Policy index : 1

Entity

after “a/c”

policy index : 0

policy name : gold

“a/c_bronze”

policy index : 2


“a/c_silver”

policy index : 1


“a/c_bronze/o”

Policy index : 2

Entity

“a/c_silver/o”

Policy index : 1

Entity

Object

Container

Link object

“a/c/o”

Policy index : 0


“a/c/o”

Policy index : 0








before “a/c”

policy index : 0

policy name : gold

“a/c_bronze”

policy index : 2


“a/c_silver”

policy index : 1


“a/c_bronze/o”

Policy index : 2

Entity

“a/c_silver/o”

Policy index : 1

Entity

after “a/c”

policy index : 0

policy name : gold

“a/c_bronze”

policy index : 2


“a/c_silver”

policy index : 1


“a/c_bronze/o”

Policy index : 2

Entity

“a/c_silver/o”

Policy index : 1

Entity

Object

Container

Link object

“a/c/o”

Policy index : 0


“a/c/o”

Policy index : 0

Link to “a/c_bronze/o”







before “a/c”

policy index : 0

policy name : gold

“a/c_bronze”

policy index : 2


“a/c_silver”

policy index : 1


“a/c_bronze/o”

Policy index : 2

Entity

“a/c_silver/o”

Policy index : 1

Entity

after “a/c”

policy index : 0

policy name : gold

“a/c_bronze”

policy index : 2


“a/c_silver”

policy index : 1


“a/c_bronze/o”

Policy index : 2

Entity

Object

Container

Link object

“a/c/o”

Policy index : 0


“a/c/o”

Policy index : 0



This Demo show you states of Swift with a Deliverer.

• State 1 • A object is in original container

• State 2 • The object’s policy is changed from the original to a derivative

• State 3 • The object’s policy is changed from a derivative to another

derivative

• State 4 • The object’s policy is changed from a derivative to the original

Note :

In this demo, our demo middleware “delivery-address” is in Swift.

The delivery-address middleware convert

“POST a/c /o ‘X-Delivery-Address:silver ’” to

“PUT .delivery_task/XXX/<index of silver>:a/c /o”

The delivery-address” middleware is NOT a component of automated-tiering.

DEMO


• Thank you for your listening.