The document discusses developing always available mobile apps with Couchbase Mobile by using Couchbase Lite for offline data storage and Sync Gateway for data synchronization between devices. Couchbase Lite is an embedded NoSQL database that allows storing and querying data locally on devices, while Sync Gateway handles multi-master replication and synchronization with a Couchbase Server backend. This approach allows building apps that work offline and provide fast performance both online and offline.

1. Developing Offline First Apps
with Xamarin and Couchbase Mobile
Always On and Available Mobile Apps
Martin Esmann
Developer Advocate, Developer Experience
1

2. Who’s to blame
Martin Esmann
Copenhagen
Windows/.NET
Enterprises, startups, students
@martinesmann –
martin@couchbase.com
2

3. Who is Couchbase?

4. Couchbase at a Glance
Fastest growing NoSQL
database company
4x growth in 2013
Mission critical use at
Internet scale
400+ customers; 10,000+ paid
production nodes deployed;
worldwide customer base
Leader in scalability &
performance
Easily & reliable scale your app;
Get consistent low latency &
high throughput
Worldwide operations
with 250+ employees
100+ in engineering; Offices in US,
UK, India, Japan, China (soon)
4

5. What is a NoSql Key-Value store?

6. 7
Relational Data
User
Type Name
Int UserId
String Name
OrderLine
Type Name
Int OrderLineId
Int ProductId
String Product Name
Int ParentOrderId
Int Quantity
Order
Type Name
Int OrderId
String Title
Address OrderAddress
Int UserId
Product
Type Name
Int ProductId
double Price
String Product Name
String Description
Web Page
Order details for
user
[User, Order,
OrderLine’s,
Product]

7. 8
De-normalizing data
User
Type Name
Int UserId
String Name
OrderLine
Type Name
Int OrderLineId
Int ProductId
String Product Name
Int ParentOrderId
Int Quantity
Order
Type Name
Int OrderId
String Title
Address OrderAddress
Int UserId
Product
Type Name
Int ProductId
double Price
String Product Name
String Description
Web Page
Order details for
user
[User, Order,
OrderLine’s,
Product]

8. 9
Key-Value Storage
Web Page
Order details for
user
[User, Order,
OrderLine’s,
Product]
Document
{
”Order": {
"Id": ”Order-1-93459328572015",
”Address": ”Street, Copenhagen",
”OrderLines": [
”Order::21342134”,
“Order::34824282”
],
"Time": "2015-04-15T00:20:00",
”Header": ”New Monitors for developers",
”User": ”martinesmann"
},
"type": ”order"
}

9. Couchbase Mobile

10. What is the business problem?

11. Today’s Mobile Apps
12
Try again
later.
No Internet
please wait…

12. How does this affect what people think about your
app?
13
Doesn’t work a lot of the time and when
it does it’s slow.

13. How does this affect application uninstall
rates?
14
0%
20%
40%
60%
80%
100%
UninstallRate
Freezing
Crashing
Slow Responsiveness
Source: uSamp

14. Data Location is the Problem
15

15. Local Data + Sync is the Solution
16

16. What does this mean for your apps?
17
Always work both online & offline
Always perceived as being blazing fast
Built with orders of magnitude less code
Users get what they expect from a modern
app

17. What is Couchbase Mobile?

18. Couchbase Lite Sync Gateway

19. Couchbase Lite
NoSQL mobile database.
Runs in-process.
Small footprint.

20. Document-Oriented Database
o Key-value collections, with versioning
o Schemaless
o Code fast. Run fast

21. {
”Order": {
"Id": ”Order-1-93459328572015",
”Address": ”Street, Copenhagen",
”OrderLines": [
”Order::21342134”,
“Order::34824282”
],
"Time": "2015-04-15T00:20:00",
”Header": ”New Monitors for developers",
”User": ”martinesmann"
},
"type": ”order"
}

22. var database = Manager.SharedInstance
.GetDatabase("database-name");
var doc = database.CreateDocument();
doc.PutProperties(new Dictionary<string, object> {
{"key1","value1"},
{"key2","value2"}
});
var doc = database.GetDocument(id);
var value1 = doc1.UserProperties["key1"];
var value2 = doc1.UserProperties["key2"];
var doc = database.GetDocument(id);
doc.Delete();

23. o Build indexes in your native language
o Results are persisted for fast querying
o Just set breakpoints to debug!
MapReduce Indexes

24. Manager.SharedInstance.GetDatabase(DatabaseName)
.GetView("all-docs")
.SetMap((doc, emit) =>
{
emit(doc["_id"], null);
},
”revision#2");

25. o Listen/Observe for changes.
o Databases, queries, replications—even documents.
o Enables responsive code patterns.
Change Notifications

26. doc.Change += (sender, e) => {
if (e.Change.IsConflict)
{
// well then resolve it!
}
};

27. Sync
o Full multi-master replication.
o Continuous or ad-hoc in either direction.
o Change notifications & conflict detection.
o Filters, Authentication & Authorization

28. var pull =
Manager.SharedInstance.GetDatabase(DatabaseName).CreatePullReplication(RemoteSyncUrl);
pull.Continuous = true;
pull.Changed += ReplicationProgress;
pull.Start();
var push =
Manager.SharedInstance.GetDatabase(DatabaseName).CreatePushReplication(RemoteSyncUrl);
push.Continuous = true;
push.Changed += ReplicationProgress;
push.Start();

29. Cocoapods
Maven
Central
Nuget
Github

30. Demo
Couchbase Lite – Intro

31. o Authentication
o Authorization
o Data orchestration
Sync Gateway

32. 33

33. o requireUser (username)
o requireRole (rolename)
o requireAccess (channels)
Sync Function

34. o channel (name)
o access (username, channelname)
o role (username, rolename)
Sync Function

35. Orders Products
Customers
Admin

36. {
"interface":":4984",
"adminInterface":":4985",
"log":["CRUD", "CRUD+", "HTTP", "HTTP+", "Access", "Cache", "Shadow",
"Shadow+", "Changes", "Changes+"],
"databases":{
"sync_gateway":{
"server":"http://10.0.0.4:8091",
"bucket":"sync_gateway",
"users": { "GUEST": {"disabled": false, "admin_channels": ["*"]}},
"sync":`function(doc) {channel(doc.channels);}`
}
}
}

37. Environment Setup
Couchbase Lite + Sync Gateway + Couchbase Server + Azure

38. App

39. What about the backend?

40. Couchbase Server - Multi-purpose
capabilities
High availability
cache
Key-value
store
Document
database
Embedded database Sync
management
Support’s a broad range of apps and use cases
Enterprises often start with cache, then broaden usage to other apps and use cases

41. Demo
Couchbase Lite – Sync demo

42. Questions?

43. Resources – continue the adventure
44
Couchbase Lite Documentation
http://developer.couchbase.com/mobile/develop/guides/couchbase-lite
Sync Gateway
http://developer.couchbase.com/mobile/develop/references/sync-gateway
Couchbase Server
http://docs.couchbase.com/admin/admin/Couchbase-intro.html
Couchbase Blogs
https://forums.couchbase.com
Demo Repo/Source
https://github.com/couchbaselabs/ToDoLite-Xamarin-Forms

44. Questions?
Continue the conversation online…
forums.couchbase.com

45. Thanks for listening!
Martin Esmann
Developer Advocate, Developer Experience
Twitter: martinesmann
E-mail: martin@couchbase.com