ING is truly positioning themselves more and more as a technology driven company. “The ING way” is all about finding new opportunities and products to exceed customers' expectations and to make sure that we focus on how to deliver the product instead of developing different products catering to the same need. Over the past 2 years ING is adopting Cassandra fast and at the same time, ING is also focusing on the Customer Experience using a touch-point architecture based more and more on micro-services. For most API’s Cassandra is a perfect match whilst easing availability challenges by being active-active and having an always-on architecture. However, at ING we have a plenty of relatively small use cases which makes justifying dedicated clusters difficult due to avoiding SAN and hardware choices already made. There for a shared cluster is inevitable. We call this KaaS – Keyspace as a Service and can be compared to a hotel with tenants. One crucial aspect is that we need to create a sandbox environment for the entire organization as implementing Cassandra is hard and requires experience and un-learning. Gary Stewart and Christopher Reedijk share our experiences on how we are making the switch to NoSQL accessible for the whole organization. It is far from easy and we will also talk about how we are addressing containment and a cost model for the hotel rooms.

1. There and back again,
ING’s Cassandra Tale
Datastax Summit 2016
Gary Stewart, @Gaz_GandA
Christopher Reedijk, @creedijk
London, April 19, 2016

2. Market leaders Benelux
Growth markets
Commercial Banking
Challengers
2
European map
Full-service bank
Very strong European base
IT is something ING does
Largest bank of NL
150+ Squads
20+ use cases in production

3. Engineer / Architect Engineer / Chapter Lead
3
a little bit about us
Gary Stewart Christopher Reedijk
#DataStaxSummit

4. 4
the contract … #DataStaxSummit

5. 5
an unexpected party #DataStaxSummit
DevOpsEngineers
Managers
InfraEngineers

6. 6
an unexpected journey #DataStaxSummit

7. Financial Fit
7
#DataStaxSummit

8. the trolls of data modeling
8
#DataStaxSummit

9. Think about the queries first!
Sometimes storing JSON in text
is best
saved by …
9
#DataStaxSummit

10. Lonely Planet
10
#DataStaxSummit

11. 11
the goblins of data querying #DataStaxSummit

12. Don’t do table scans
Think about Read path
i.e. avoid increasing sequential
reads as data grows
Do performance tests even for
small use-cases!
12
saved by … #DataStaxSummit

13. iDeal
13
#DataStaxSummit

14. 14
the riddles of Gollum #DataStaxSummit
What could go wrong this time ….

15. NTP killed the happy flow
Customers couldn’t go to next page 
the riddles of time
15
#DataStaxSummit

16. NTP killed the happy flow
Customers couldn’t go to next page 
Versioning to the rescue
saved by …
16
#DataStaxSummit

17. Experiments API
17
#DataStaxSummit

18. Aggressive distributed
Read-after-Write, causing
read-repair-blocking
18
the spiders of 99 percentile #DataStaxSummit

19. Be careful with read-after-write
Always check the functionality
of the framework you’re using
19
saved by … #DataStaxSummit

20. Cached Data
20
#DataStaxSummit

21. SizeTieredCompactionStrategy
Default, compact after 4 sstables
20GB data needs 100GB+ storage
the loss of storage
21
SST1 SST1 SST2 SST1 SST2 SST3 SST1 SST2 SST3 SST4 SST5
FLUSH
FLUSH
FLUSH FLUSH
COMPACT
#DataStaxSummit

22. Data space required is now
around 50% less!
Attention to details can save i/o
and disk space
saved by …
22
SST1 SST1 SST2 SST3
FLUSH
FLUSH
COMPACT
#DataStaxSummit

23. Fraud Investigation
23
#DataStaxSummit

24. Bad performance and nodes
dying constantly
Network and GC issues
Hinted handoffs going crazy
Very long GC-pauses causing nodes to freeze
Never ending compactions
24
the wood elves of network #DataStaxSummit

25. Take a step back
Upgraded to 4.8.5
with G1GC (default when using Java 8)
4.7.3 is way too chatty
Increased heap and new to
16GB and 8GB
for coordinator nodes,
which in our case are all 
25
saved by … #DataStaxSummit
Incoming
Traffic

26. 26
the desolation of smaug #DataStaxSummit

27. Think top-down – queries first
Talk about failures
Experimentation – Sandbox
Environment that is safe to fail
Take a step back
understand the architecture
flow of data
ensure you are understanding the problem
27
desolated by … #DataStaxSummit

28. 28
the battle of 5 armies #DataStaxSummit

29. 29
the battle of 5 armies #DataStaxSummit
InfraEngineers
DevOpsEngineers
Architects
???
Managers

30. Each time we ventured out there
with new insights ready to take on new epic
challenges
And each time we came back
Bit bruised but never broken 
More willing to share
And rolled out into PRD
30
there and back … #DataStaxSummit

31. again and again and again …
31
#DataStaxSummit

32. Thank you
christopher.reedijk@ing.nl
@creedijk
gary.stewart@ing.nl
@Gaz_GandA
visuals by Isabelle Hörl:
www.isabellehorl.com | @IsabelleHorl
we are hiring!

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