1. Kevin Wright
Jonathan Roeder

2.  Kevin Wright (The long-haired hippie one)
◦ Over 100 years of experience! (Just look at this
PowerPoint Template!)
◦ Worked on the Space Station!
◦ 2 years of Mongo experience
 Jonathan Roeder (The short-haired hipster
one)
◦ 10 years of High Scale eCommerce / CMS / Search
◦ 1.5 years of Mongo experience

3.  Founded in 1999
 SaaS eCommerce and related services
 40,000+ Online stores
 330+ Employees
 $2.8B processed on our platform in 2012

5.  Dog Fridays
 Guys in suspenders!

6.  Just who are you guys?

7. WHY write one?
The world needed ONE MORE!?!
Critical focus on
 Multi-Tenancy
 Focus on Small footprint / Efficient scaling

8. What it is:
 .NET REST Service
 Standard use case of enabling CMS users to
define Meta schemas (Content & Property
Types)
 CRUD operations on Data that conforms to
the Meta schemas (Content)
 Structures for organizing Content (Content
Lists and Folders)

9.  Initial approach programmatically provisioned
a Mongo Database for each Tenant.
 Reinventing the wheel with database
management.
 Suffering from two minute incremental boot
up time per Database was untenable (get it!).
 New approach: Embrace Sharding as the
appropriate scale out approach

10.  Opt-in per Collection
 Don’t do it to earn your Sharding merit badge
 Read the documentation three times.
 Implement four times. (a.k.a Prototype)
 The Along Came Polly joke will never get old

11.  .NET static type system + MongoDB dynamic
schema is like mixing Simon and Garfunkel
…(it can be great if you don’t Garfunkel it up)
 Driver allows for pure dynamic schema
interaction but is maturing to allow type safe
access via Lambdas and LINQ.
◦ Aggregation framework tbd [CSHARP-601]

12. KEVIN WILL DEMO
 Mongo SHELL
 MONGOVUE
 LINQPAD

13.  Be as static as you can be.
◦ POCO types for each MongoDB Document schema
(Data Transfer Object, DTO pattern)
◦ Leverage compile-time safety. The newest driver
makes it easy with Generics and Lambdas
◦ Duck-typing and magic strings are for gooses!
 Explore very rich serialization hooks and
levers
◦ (SetIgnoreIfNullConvention, BsonExtraElements,…)

17.  Now that you’ve created static types, leverage
them!

18.  LINQ support is great. Just know that:
◦ No projection [CSHARP-456]
◦ Hard to mix in dynamic schema elements (use Inject
extension method)
 Fall back to
MongoDB.Driver.Builders.Query<T> or
QueryBuilder<T>
◦ Mix in dynamic schema elements via non-generic
version

19. 3 HIT
COMBO
!!!

20.  Laser focus your Updates

21.  Be careful with the blanket Save method!
◦ Can’t stop it from Upserting
◦ Often overkill to replace entire Document

22.  Data modeling without Joins
 Concurrency modeling without Transactions

23.  Denormalize!

24.  If your data can’t be dirty, don’t denoramlize
 Example: Store only the FolderId on Content
Document instead of materialized Folder path
◦ Pros: Updates are easy!
◦ Cons: Queries are hard!
◦ When wanting to find Content within child
Folders, must first query for all child Folders, then
OR those IDs using the ‘In’ operator

27.  MongoDB.org approaches for actually
retrieving the Folders :
http://docs.mongodb.org/manual/tutorial/m
odel-tree-structures/

28.  Optimistic Concurrency
 Benign Writes
 Benign Wrongs
 Compensate
 Be prepared to carefully think this through.
 http://blog.mongodb.org/post/475279604/
on-distributed-consistency-part-1
 http://docs.mongodb.org/manual/tutorial/p
erform-two-phase-commits/

29.  Vote!