1. Adventures
with
micro-Services
Mohit Thatte (@mohitthatte)
Jesal Mistry (@jesalnmistry)
ThoughtWorks Inc.

2. What?
Why?
How?
When?

3. Components
Library Service

4. What are micro services?
small independent composable
services
that do one thing well

5. Unix philosophy
Write programs that do one thing well.
Write programs that work together.
cat | grep | sed | awk | ...
HTTP is the new pipe!

6. lots of legacy, no reuse
not flexible, high cost of change
no one knows how it works
concentrated complexity
independent small that do one thingcomposable
90 year old business

7. “A 100k loc app is
just 100 1k loc apps
waiting to happen”
- Jeff Bay

8. Adventure so far
25 VM’s in production
10+ micro-services
one click deployment
60+ VM’s across
environments

9. µService
DB
µService
DB
µService
DB
µService
DB

10. Orders PaymentsCustomersLegacy ResultsOrder
Processing
Catalog
(Games)

11. Thumb Rules
1 top level resource (2 at most)
bounded contexts
focus on contracts
avoid coupling
idempotent jobs
extract cross cutting concerns

12. Orders PaymentsCustomers
Communications
Legacy ResultsOrder
Processing
Scheduled
Jobs
Error
reporting
Catalog
(Games)

13. Continuous Delivery
Is my code good to go to production?
Can I deploy it in a single click?

14. “we’re effectively pushing the
complexity from the application
into the infrastructure...”
- James Lewis

15. CI + DevOps
enables
single-click deployment
so easy, our product owner does it!
it just works™
3 mins to production (~25 servers)

16. Puppet Solo
Provisioning begins at home - Vagrant
Puppet goes through CI just like app code
Our ideal : ImmutableServer
Provisioning

17. Tradeoffs
benefit cost
small units of reuse/maintenance complex infrastructure
grow independently (**polyglot) network overhead
scale independently fragmented data
“easier” to grok “harder” to grok
isolated boundaries coarse-grained API
logging / tracing