Sync Framework Synchronize Your Data On-Premises and to the Cloud

Sameh SamirSenior Software Engineer

Architecture and Infrastructure Team

MedStreaming LLC

What Will Talk About• Brief on Microsoft Sync Framework

• Why I’d Need Synchronization

• Synchronization Ecosystem: The Concert

• Framework Components

• Responsibilities

• Participants

• Application Scenarios: Offline

• Application Scenarios: Collaboration

• How It Works

• Change Tracking

• Conflict Resolution

• Concepts

• Sync Scenarios: On-Premises Two Tier Architecture

• Demo: Synchronizing Data - 2-Tier Architecture

• Sync Scenarios: In the cloud – N Tier Architecture

• Demo: Synchronizing Data : N-Tier Architecture

• Choosing Primary Keys

• Tracing

• Demo: Sync with SQL Azure

Brief on Microsoft Sync Framework

• Microsoft data synchronization platform

• Allow for Collaboration and OCA (Offline) Applications scenarios

• Announced in MIX 2008

• August 2008 – V1.0

• April 2009 – V2.0

• August 2010 – V2.1

• Q1 2011 – V3.0 (Expected)

Why I’d Need Synchronization?

• Offline Availability• Lake of offline availability maybe frustrating for some users. But can be a disaster

for others (Retail Store POS, Medical system)

• Access to Full Client Capabilities• H/W intensive applications (Imaging, Medical, 3D, Media Processing, POS Station,

etc…)

• User Experience• Asynchronous processing improves usability, but you still have to wait• Cache management will be a headache if you would cache everything

• Mobility• Request for mobile accessibility increases• Mobile accessibility is a must for some businesses • Mobile internet still not cheap

Qualities of MSF

• Ease of use

• High Level of Customization

• Data and Transport Agnostic Sync Functionality

• Build - in Providers

• Extensibility

• Custom Providers Framework

Synchronization Ecosystem: The Concert

Sync Provider

Sync Application

Sync Provider

Sync Orchestrator

DataStore

Data Store

changes

changes changes

changes

Metadata Interpretation

Tools

Provider Services

MD StoreSync Runtime

Framework Components

Sync Runtime (Orchestration)

KnowledgeVersionChange

Enumeration

Basic Building Blocks

Built-In Providers

Conflict Detection

Metadata Storage Service

Anchor based Providers

Simple Providers

SQL Sync Provider

SQL CE Sync Provider

File Sync Provider

Feed Sync Provider

End to End Solutions

IDE Integration

Other MS & 3rd Party Providers / Solutions.…ADO Sync

Services

Db Sync Provider

Sync for OData

Full Enumeration Providers

Responsibilities

Developer:• The application• The data store• The data transfer protocol

Sync Framework:• Synchronization session, or manager• The synchronization runtime

Sync Framework, or the Developer:• The sync provider• The metadata store

Participants

• Full Participants: Devices that allow developers to create applications and new data stores directly on the device. E.g. Windows Phone, laptop

• Partial Participants: Devices that have the ability to store data either in the existing data store or another data store on the device but do not have the ability to launch executables. E.g. thumb drives or SD Cards.  

• Simple Participants: Devices that are only capable of providing information when requested. These devices cannot store or manipulate new data. E.g. RSS Feeds and web services.

Application Scenarios: Offline

• All clients sync through a single hub (Server)

• Suitable for Occasionally Connected Applications (OCA)

• Single point of failure

• The most common, and easier to implement

Application Scenarios: Collaboration

• Suitable for application where users needs to share data (i.e notes, documents, calendars, project info)

• Each client can sync with other clients or with a central server

• Avoid single point of failure

• Offload the sync processing from server to clients, and thus provide more scalability

• Less common and more complex to implement.

Is metadata up-to date

How It WorksEnumeration

Sync Orchestrator

ProviderFramework

with Runtime

Sync Provider

DataStore Meta-data

Store

GetChangeBatch

Enumerate all objects

Here’s one:Id=‘foo’, LMT=5pm

What was it last time?New

Updated

Same

Update metadata

Bring metadata up-to-date

Enumeratechanges

Metadata is up-to-date!

All done!

What’s missing?

Record deletes

…

How It Works (Cont.)Applying Changes

Sync Orchestrator

ProviderFramework

with Runtime

Sync Provider

DataStoreMeta-data

Store

Enumerate all objects

Here’s one:Id=‘foo’, LMT=5pm

What was it last time?

New

Updated

Same

Update metadata

Bring metadata up-to-date

Metadata is up-to-date!

All done!

What’s missing?

Record deletes

…

ProcessChangeBatch

Get versions

Update item id=‘foo’

LMT was 1pmNew data is ‘bar’New LMT=8pm

Check LMTand write

Updatemetadata

Change Tracking• Change tracking provides a list of changes made from one point in

time to another.

• Commonly implemented using rowversions and triggers, plus a “deleted” table

• The major disadvantages are:• Changes are required to the schema to add columns and tables• Triggers are fired for each change made, which has performance implications.

• SQL Server 2008 has built-in change tracking, implemented without rowversions and triggers

• The Sync Framework database synch providers take advantage of SQL Server 2008 change tracking and provide the following advantages :• No schema changes are required• Triggers are not required for tracking changes• All of the logic for tracking changes is internal to the SQL Server engine

Conflict Resolution

• Conflicts occur when two or more databases make a change to the same piece of data

• A variety of ways to resolve these conflicts. • Last change to come in wins• Highest priority user wins• Manual selection

• Sync Framework provides conflict detection and resolution capabilities out of the box

• SQL Server 2008 makes it easier to identify conflicts.

Concepts

• Sync Scope: • Set of tables that will be available for synchronization

• Sync Group:• Group of that must be synchronized as a single unit (transaction)• Ensure data consistency

• Provisioning a Server• Get the server ready for change tracking• Add change tracking columns and triggers for SQL Server 2005• Enable change tracking feature for a set of tables of a SQL Server 2008

database• Can be done programmatically or through “Configure Data

Synchronization” wizard

Sync ScenariosOn-Premises (Two-Tier Architecture)

Sync Provider

Sync Application

Sync Orchestrator

DataStore

Sync Provider

DataStore

Data ServerClient

DEMOSynchronizing Data - 2-Tier Architecture

Sync ScenariosIn The Cloud (N-Tier Architecture)

Sync Provider

Sync Application

Sync Orchestrator

DataStore

Sync Provider

DataStore

Data ServerClient

Proxy

DEMOSynchronizing Data - N-Tier Architecture

Table Key Selection

Take it seriously, or else

Table Key Selection : The Problem

Client 1 Client 2

1 Customer 1 …

100 Customer 100 …

1 Customer 1 …

100 Customer 100 …

101 Customer 101 …

1 Customer 1 …

100 Customer 100 …

101 Customer 101 …

101 Customer 101 …

Duplicate Key Conflict

Table Key Selection : Solutions

1. Use GUID instead of auto incremented IDs• Solve primary key collisions possible with auto-increment

columns• Increased index size leads to increased query time• Causes fragmented clustered index, which also affects query

processing time. • Can be solved in SQL Server by using NEWSEQUENTIALID

function to generate ordered GUIDs

2. ID Ranges• Split available IDs into segments• Assign each client a unique segments• Client can ask for more ID ranges

Table Key Selection : Solutions (Cont.)

3. Compound Keys

• Use compound key that includes a client identifier

4. Use Business Key as ID

• Use unique business keys (i.e National Number / SSN / Barcode)

• May affect the query performance if key type is not numerical.

5. Online Insert

• Insert directly to the server

DEMOEnable Tracing

DEMOSync To SQL Azure

Q&A

Call To Action

Azure Table Sync Library (azuretablesynclib.codeplex.com)

Open source project aims to create custom data sync providers to allow for the following sync sceanrios

1. Azure Table Storage <-> SQL Server / Express

2. Azure Table Storage <-> SQL CE

3. Azure Table Storage <-> SQL Azure

4. Azure Table Storage <-> Azure Table Storage

Keep in Touch

Email: sameh.sami@gmail.com

Blog: www.Cloudy-Ideas.net / www.sameh-samir.net

Twitter: twitter.com/sameh_samir

LinkedIn: linkedin/in/samehsamir