The document discusses integrating Datomic Cloud, a managed Datomic database service, with AWS AppSync. It begins with an introduction to Datomic and its key features. It then demonstrates how to set up a basic Datomic Cloud environment. The remainder discusses how Lambda functions could be used to expose Datomic queries and transactions via AppSync resolvers, enabling access to Datomic Cloud through any language supported by AppSync. Future work is noted around publishing an integration library.

1. DATOMIC CLOUD AND
AWS APPSYNC
SERVERLESS CHICAGO - APRIL 26, 2018

2. INTRO
YOUR HUMBLE NARRATOR
▸ Chris Johnson Bidler
▸ CTO at Centriq Technology, Inc.
▸ Previously Transunion, SPS Commerce, McKesson
▸ Lots of Java -> Quite a bit of Devops -> Architecture
▸ AWS Certified Associate Developer, SA, Devops
Engineer
▸ chris@centriqhome.com

3. SO WHAT ARE WE DOING?
ORIGINAL PLAN
▸ Talk about Datomic generally
▸ Walk through new developments re: Datomic Cloud
▸ Show a very simple integration of Datomic Cloud and a
generic Lambda/Serverless environment

4. SO WHAT ARE WE DOING?
THEN CAME REACT AMSTERDAM…

5. SO WHAT ARE WE DOING?
NEW PLAN!
▸ Talk about Datomic generally
▸ Walk through new developments re: Datomic Cloud
▸ Set up a Datomic Cloud environment
▸ Do the minimum to make it amenable to participation in
AppSync resolvers
▸ Show that instead

6. DATOMIC
SO WHAT IS “DATOMIC”?
▸ https://www.datomic.com
▸ Database of immutable facts rather than mutable records
▸ Not a relational store - entities can have any attribute without
sparse tables or complex joins
▸ Not a NoSQL store - attributes and value types are specified in a
schema
▸ Each fact is comprised of:
▸ Entity, Attribute, Value, Time

7. DATOMIC
EXAMPLE FACT - JOHN LIKES PIZZA
e: <opaque id ref for “John”>,
a: “likes”,
v: [“Pizza”],
t: 100
EXAMPLE FACT - JOHN LIKES PIZZA AND ICE CREAM
e: <opaque id ref for “John”>,
a: “likes”,
v: [“Pizza”, “Ice Cream”],
t: 191

8. DATOMIC
EXAMPLE FACT - JOHN LIKES MIXING THINGS UP
e: <opaque id ref for “John”>,
a: “likes”,
v: [“Pizza”, “Ice Cream”, “Beer”],
t: 224
EXAMPLE FACT - JOHN HAD A BAD EXPERIENCE
e: <opaque id ref for “John”>,
a: “likes”,
v: [“Pizza”],
t: 301

9. DATOMIC
USEFUL PROPERTIES OF DATOMIC
▸ Data modeling is (almost all) deferred to query time
▸ Accumulate-only, immutable stream of facts means that you can
create arbitrary “views” over your data just by writing (or
refining) a query
▸ Reads can scale arbitrarily - peers read directly from storage and
don’t need to coordinate with anything to pull reads
▸ Writes create a consistent state that can be replayed, queried,
etc. (“what was every value of the db at the time this bug
occurred”)

10. DATOMIC
QUERYING A DATOMIC DATABASE
▸ Datomic exposes a logic programming query model called
Datalog (modeled on Prolog/Cascalog)
▸ Allows you to ask interesting questions about the db as a whole
▸ Walking a graph-like structure is simple because you can have
reference attributes on any entity which point to another entity
as the value
▸ Since queries are against an immutable set of facts, even
queries that consider a large amount of data can be quite fast

11. DATOMIC CLOUD
SO WHY DOESN’T THIS GET USED EVERYWHERE?
▸ First-class language is Clojure
▸ Publishing of the wire protocol for clients is Coming
Soon™
▸ Robust native support for languages other than Clojure
(incl. Clojurescript) is On The Roadmap™
▸ Until recently, the way to run it was to pay an enterprise
license fee and stand up some beefy EC2 instances that
you own, upgrade, monitor, etc.

12. DATOMIC CLOUD
ENTER DATOMIC CLOUD
▸ AWS Marketplace offering
▸ Completely managed Datomic database-as-a-service
▸ “Solo” topology is good enough for experiments and PoC,
costs about a dollar a day
▸ “Production” topology costs more, has much better
resilience, beefier compute, better CloudWatch dashboard

13. DATOMIC CLOUD
STANDING UP DATOMIC CLOUD SOLO

14. DATOMIC CLOUD
STANDING UP DATOMIC CLOUD SOLO - STACKS UP

15. DATOMIC CLOUD
STANDING UP DATOMIC CLOUD SOLO

16. DATOMIC CLOUD
STANDING UP DATOMIC CLOUD SOLO - DASHBOARD

17. DATOMIC CLOUD
STANDING UP DATOMIC CLOUD SOLO - POLICY FOR ADMINS

18. DATOMIC CLOUD
STANDING UP DATOMIC CLOUD SOLO - ADD SSH IN FROM ?

19. DATOMIC CLOUD
WORKING AT THE CLOJURE REPL - ADDING SCHEMA

20. DATOMIC CLOUD
WORKING AT THE CLOJURE REPL - ADDING SCHEMA

21. DATOMIC CLOUD
WORKING AT THE CLOJURE REPL - ADDING DATA

22. DATOMIC CLOUD
WORKING AT THE CLOJURE REPL - QUERYING

23. DATOMIC CLOUD
WORKING AT THE CLOJURE REPL - QUERYING

24. INTEGRATION WITH APP SYNC
WHAT ARE THE CLOJURE “ENDPOINTS” IN THE API?
▸ datomic.api/transact
▸ Takes a configured connection and transacts a set of datoms
▸ Can be synchronous or async
▸ datomic.api/query
▸ Takes in a query form and a database (fetched from a connection)
▸ Returns the data in the form specified by the query
▸ Can be synchronous or async

25. APPSYNC INTEGRATION
WHAT IF WE JUST …WROTE A COUPLE OF LAMBDAS?

26. INTEGRATION WITH APP SYNC
GIVEN A SCHEMA…

27. INTEGRATION WITH APPSYNC
AND LAMBDA DATASOURCES FOR QUERY AND TRANSACT…

28. INTEGRATION WITH APPSYNC
AND LAMBDA DATASOURCES FOR QUERY AND TRANSACT…
arn:aws:lambda:us-east-2:283544993916:function:datomic-cloud-query

29. INTEGRATION WITH APPSYNC
AND EVEN MINIMAL CLOJURE CODE TO LIVE IN THAT LAMBDA…

30. APPSYNC INTEGRATION
…RESOLVERS IN ANY LANGUAGE CAN PASS
QUERIES AND MUTATIONS TO/FROM DATOMIC CLOUD!

31. TODO
FUTURE WORK FOR ME
▸ Publish a library that:
▸ Provides less-minimal transactor and query Lambda functions
for use with AppSync
▸ Provides a method to generate Datomic schema from
GraphQL schema statements and auto-transact them
▸ Flesh out example with Amplify and a more-real schema
▸ ???
▸ Profit!

32. QUESTIONS?
THANKS FOR WATCHING!

33. REFERENCES
▸ https://medium.com/@jamesleonis/clojure-and-aws-
serverless-basic-lambda-201b60183d6d
▸ http://www.flyingmachinestudios.com/programming/
datomic-for-five-year-olds/
▸ https://augustl.com/blog/2018/
datomic_look_at_all_the_things_i_am_not_doing/
▸ https://docs.aws.amazon.com/appsync/latest/devguide/
tutorial-lambda-resolvers.html