MN Enterprise Mobile User Group April 2015 Meeting

@rbaconsultingwww.rbaconsulting.com blog.rbaconsulting.com

Mobile Sync with Couchbase and

Azure Mobile Services

Joe Koletar

A Digital and Technology Consultancy

Agenda

• Sync background

• Azure Mobile Services Sync

• Couchbase Sync


Mobile DataA

lways

Co

nnect

ed • Store data

remotely

• Access via REST

• Requires

connection

• Can be slowN

eve

r C

onnect

ed • Store data

locally

• Access via

SQLite

• Connection not

required

• Always available

So

metim

es

Co

nnect

ed • Store data

locally and

remotely

• Access via

SQLite and

REST

• Connection not

required

• Always available


What is Sync

• Supports occasionally connected mobile access.• Provides a rich user experience

• Retrieves updates when connected

• Store offline updates until connected


Sync Challenges

• Managing changes• Server

• Adds

• Deletes

• Updates

• Client• Adds

• Deletes

• Updates

• Need to resolve conflicts


Approaches to manage sync

• Timestamp

• Id hell

• Guids

• Compete replacement


Azure Portal



• Can dynamically define tables• GUID Ids required

• Must create a SyncContext• Tracks PendingOperations

• Merges updates that haven’t been synced


Push/Pull/Purge

• PushAsync

• Must push all tables

• Maintains referential integrity

• PullAsync

• Works per table

• Can specify tables to pull via LINQ query

• Executes Push first to empty PendingOperations

• PurgeAsync

• Clears items from the local store

• Executes Push first to empty PendingOperations


Conflict resolution

• Throws MobileServicePushFailedException

• Can provide sync handler on client in InitializeAsync

public interface IMobileServiceSyncHandler

{

Task OnPushCompleteAsync

(MobileServicePushCompletionResult result);

Task<JObject> ExecuteTableOperationAsync

(IMobileServiceTableOperation operation);

}


Couchbase

• Awesome demo at Evolve

• Near instantaneous synchronization between devices


Couchbase


Sync Gateway

• Traffic cop of the configuration

• Bidirectional, multi-master sync

• Manages and authenticates users

• Authorizes document access

• Routes documents to users


Sync Gateway

• Two APIs• Sync REST API – port 4984

• Admin REST API – port 4985

• Sync Function

• Conflict resolution pushed to device


Couchbase Server

• Must have sync_gateway data bucket

• Stores synced data and corresponding metadata


Couchbase Client

• Database.CreatePullReplication

• Database.CreatePushReplication


Sync Function

• JavaScript Function• Enforce validity or schema

• Enforce role membership

• Tag document with channels

• Grant users access to channels


Sync Gateway

• Configuration• Command line

• JSON Configuration file

{ "log": ["CRUD+", "REST+", "Changes+", "Attach+"],

"databases": {

"sync_demo": {

"server":"http://localhost:8091",

"bucket":"sync_gateway",

"sync":`function(doc) channel(doc.channels);}`,

"users": {"GUEST": {"disabled": false,

"admin_channels": ["*"]}

}

}

}

}


Sync Gateway Users

• Sync Gateway manages mobile user accounts

• Authentication mechanisms• HTTP Basic

• Session cookie

• Facebook

• Custom


Channels

• Tags attached to documents

• Used to link users to documents

• Users mapped to channels


Channels


References

• Azure Mobile Services• http://channel9.msdn.com/Series/Windows-Azure-Mobile-Services/Build-

offline-apps-Azure-Mobile-Services

• http://blogs.msdn.com/b/azuremobile/archive/2014/04/07/deep-dive-on-the-offline-support-in-the-managed-client-sdk.aspx

• Couchbase• Evolve presentation: https://www.youtube.com/watch?v=g7WlnfvOvhI

• https://www.youtube.com/watch?v=g1EVj9B5Z6g

http://channel9.msdn.com/Series/Windows-Azure-Mobile-Services/Build-offline-apps-Azure-Mobile-Services

http://blogs.msdn.com/b/azuremobile/archive/2014/04/07/deep-dive-on-the-offline-support-in-the-managed-client-sdk.aspx

https://www.youtube.com/watch?v=g7WlnfvOvhI

https://www.youtube.com/watch?v=g1EVj9B5Z6g

MN Enterprise Mobile User Group April 2015 Meeting

Mobile

Transcript of MN Enterprise Mobile User Group April 2015 Meeting