This slides was talked at Couchbase Mobile Ideathon in Tokyo on Aug 29th, 2014. Please contact us (couchbasejp@couchbase.com) if you have any questions.

1. Couchbase Mobile Ideathon
Traun Leyden
Lead Android Developer
tleyden@couchbase.com
10/29/13

2. About me
• I was previously at a startup company doing a
mobile CRM app — we converted our app to
Couchbase Lite to solve networking performance
issues
• Now I work full time as the lead developer on
Couchbase Lite Android
• I also work on demo apps on both iOS and Android
• I have blog at http://tleyden.github.io

3. About Couchbase
• Was the merger of two companies
• CouchOne (commercial support for CouchDB)
• Membase (a commercially supported / distributed
version of memcached)
• Our flagship product is Couchbase Server, a fault
tolerant distributed database.
• We recently released Couchbase Mobile, targeted
towards mobile and embedded devices/sensors.
• All of our products are released as Open Source
software under the Apache2 license.
• We now have an office in Japan

4. Why would you want to use
Couchbase Mobile?
Will your app work when the network is
slow or only sometimes connected?
?

5. We think our network is fast, but ..
• On trains or underground
• Large crowds
• Out of the city center
• Deployed on sites which have unreliable
Wifi
• Sometimes you are completely offline
• Etc ..

6. The simplest use case — sending a
tweet on the subway
Users expect better than this!

7. Our solution - Sync

8. Your app reads/writes to a local
database
This will be fast even if the network is slow or offline

9. Couchbase Lite sync’s the data to the
cloud (can run in background)

10. TodoLite Demo
• TodoLite is a todo list app
• Users can login via Facebook
• Users can share todo lists with each
other
• Different users can both view and
update the same list
• Photo attachments can be added to
Todo items
• Supports conflict resolution
• Source code available on github (see
resources slide)
• Available in iTunes app store and
Google Play

11. Understanding sync gateway
• Sync Gateway can control which
users can see which documents.
• In effect, it can partition the
database so that users only see a
subset of the database

12. Partitioning a database by company
and region

13. Using Sync Gateway to partition a
database
• Sync Gateway can do this efficiently
• The main reason it was created
• Sync Gateway uses “channels” to do
this
• Let’s walk through an example

14. Using Channels in
OfficeRadar Example
OfficeRadar uses iBeacons to detect who is in the office

15. Users should only see activity for other
users in their organization

16. Sync Function
• The sync function partitions the database by
putting documents into channels
• To understand the sync function, we must
look at the OfficeRadar documents

17. OfficeRadar GeofenceEvent Document
Each Geofence Event is associated with an
organization
{
"_id":"!QJoBU7cRa~m2E2tYloSHHN",
"_rev":"1-8e8f3cebf357a2546c0d40e497227115",
"action":"entry",
"beacon":"4a83813db6ce76e9618793cf483cfa10",
"created_at":"2014-08-28T23:43:19.119Z",
"userprofile":"10152586863333982",
"type":"geofence_event",
"organization":"couchbase"
}

18. OfficeRadar UserProfile Document
Each User Profile is associated with an
organization
{
"_id":"10152586863333982",
"_rev":"1-2b6a6e182ef77cd15db7171023931e8d",
"type":"profile",
"authSystem":"facebook",
"name":"Traun Leyden",
"organization":"couchbase"
}

19. OfficeRadar Sync Function
function(doc, oldDoc) {
if (doc.type == "geofence_event") {
channel(doc.organization);
} else if (doc.type == "profile") {
access(doc.userid, doc.organization);
}
}

20. Adding a geofence event to a channel
if (doc.type == "geofence_event") {
channel(doc.organization);
}

21. Allowing a user to access an
organization’s channel
else if (doc.type == "profile") {
access(doc.userid, doc.organization);
}

22. Views
Putting the “No” in NoSQL
• Map/Reduce mechanism
- A standard method of indexing in NoSQL
- A view is similar to index in relational database.
• App-defined map function
- Called on every document
- Can emit arbitrary key/value pairs into the index
• Optional reduce function
- Data aggregation / grouping
• Functions are registered as native callbacks
- Native callbacks make sense for performance and to match the rest of
the app codebase

23. Queries
• Basic feature set
- Key ranges, offset/limit, reverse, group by key…
- No joins or fancy sorting
- but compound keys (and clever emits) allow for some tricks
• LiveQuery subclass
- Monitors a view for changes
- Can think of it as a “pub-sub” approach
- Register a callback that is triggered when the query changes

24. Use Cases

25. Embedded
Picsolve
 Image capture of roller
coaster riders to local
database in multiple
theme park locations
 Machine to machine
communication example
 Unreliable network
connectivity required
offline capture / later sync
to centralized
management system

26. Infinite Campus
Education / Social Interaction
 Selectively push out learning
modules / multimedia lessons
to individual students
 Teachers and students use
custom mobile chat apps for
real-time Q&A during lectures
 Homework assignments can be
completed offline anywhere

27. Offline Sensor Data
A weather balloon could collect sensor data while
offline and sync it whenever it is online

28. Travel Expense Tracker
• I am in Tokyo, but my iPhone 5 is locked so I cannot use a
local SIM card.
• But I need an app to track my expenses, so I must be able to
enter expenses while offline.
• When I get back to the US, I want to sync these expenses to
the Cloud so I can download a spreadsheet.

29. Resources
• These slides will be made available on SlideShare
• Sample code links
• https://github.com/couchbaselabs/ToDoLite-Android
• https://github.com/couchbaselabs/ToDoLite-iOS
• https://github.com/tleyden/office-radar
• Documentation
• http://developer.couchbase.com/mobile
• Download
- http://mobile.couchbase.com
• Contact: couchbasejp@couchbase.com

30. Resources 2
• Couchbase Mobile Google Group (community):
groups.google.com/group/mobile-couchbase/
• Couchbase Mobile Twitter:
https://twitter.com/CouchbaseMobile
• Run Sync Gateway (and Couchbase Server!) under Docker:
http://tleyden.github.io/blog/2014/06/22/running-couchbase-
sync-gateway-on-gce/

31. Upcoming Event: Hackathon
• http://couchbasejpcommunity.doorkeeper.jp/events/13988

32. Upcoming Event:
Couchbase Server
• Couchbase Server
http://couchbasejpcommunity.doorkeeper.jp/events/14785

33. Thanks for watching!
Contact: tleyden@couchbase.com
Questions?