Slides from a talk I gave at PubNub's IoT Stream Conference

1. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 1
“ideal to store time series data”
“Apache Cassandra has never failed us.”

2. PerformanceAvailabilityScale

3. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 3
Startup Program
ToastrBox
Analytics
Search
In-memory
Visual Admin
Security
Certified Cassandra

4. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 4
IoT requires performance and reliability

5. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 5
Your
System
Send Heating Coil Repair Man
IoT requires performance and reliability

6. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 6
Your
System
Send Heating Coil Repair Man
Send 10% Off Bread Coupon
IoT requires performance and reliability

7. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 7
Your
System
Send Heating Coil Repair Man
Send 10% Off Bread Coupon
Offer Upgrade Suggestions
IoT requires performance and reliability

8. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 8
Your
System
Send Heating Coil Repair Man
Send 10% Off Bread Coupon
Offer Upgrade Suggestions Integrate with your SaaS
(Spread as a Service)
IoT requires performance and reliability

9. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 9
Your
SystemFAULT
IoT requires performance and reliability
App Down, Customers Lose Interest

10. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 10
Your
SystemSLOW
Send Heating Coil Repair Man
Three months after they
get a competitor's toaster
Offer Upgrade Suggestions
That are already out of date
Send 10% Off Bread Coupon
They've already restocked on bread
Integrate with your SaaS
(Spread as a Service)
Toast got spread a long time ago
IoT requires performance and reliability

11. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 11
Send Heating Coil Repair Man
Send 10% Off Bread Coupon
Offer Upgrade Suggestions Integrate with your SaaS
(Spread as a Service)
IoT requires performance and reliability

12. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 12
0 50 100 150 200 250 300 35
174,373
366,828
537,172
1,099,837
http://techblog.netflix.com/2011/11/benchmarking-cassandra-scalability-on.html
50 nodes
100
150
300 nodesScale

13. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 13
Horizontal scale
B
A
A B
Token Range
Mapping Data To Nodes
Ring Architecture
Peer to Peer Communication
No Masters, No Slaves

14. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 14
C
BA
D
A B
C D
Token Range
Mapping Data To Nodes
Ring Architecture
Peer to Peer Communication
No Masters, No Slaves
Horizontal scale

15. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 15
Availability
"During Hurricane Sandy, we lost an entire data center.
Completely. Lost. It.
Our data in Cassandra never went offline."

16. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Peer-to-peer architecture
16
C
BA
D
Client
Client has a holistic view
Cluster cluster = Cluster.builder().addContactPoint("192.168.0.1").build();
Cassandra Cluster

17. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved. 17
C
BA
D
Client
Client has a holistic view
Partition Keys are Hashed
to a Token Range
DeviceID: 102349
Divided data responsibility across cluster
A B
C D

18. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Controlling fault tolerance: replication factor
18
Server - Replication: How many copies of a data
should exist in the cluster?
ReplicationFactor=3
Client
Replication Strategies can span data centers!
Survive whole AWS Region Failure!
ACD
ABCABD
BCD
A B
C D

19. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Controlling fault tolerance: replication factor
19
ACD
ABCABD
BCDACD
ABCABD
BCD
US-West US-East
Server - Replication: How many copies of a data
should exist in the cluster?
ReplicationFactor=3
A B
C D

20. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Controlling fault tolerance: replication factor
20
Cassandra Cluster
ACD
ABCABD
BCDACD
ABCABD
BCD
US-East
Server - Replication: How many copies of a data
should exist in the cluster?
ReplicationFactor=3
US-West
A B
C D

21. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Controlling fault tolerance: replication factor
21
A B
C D
ACD
ABCABD
BCDACD
ABCABD
BCD
US-West US-East
Server - Replication: How many copies of a data
should exist in the cluster?
ReplicationFactor=3

22. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Controlling fault tolerance: tunable consistency
22
Client - Consistency Level: How many replicas should
we check before acknowledgement?
CL = One
Client
Successful
Toast
Made!
ACD
ABCABD
BCDACD
ABCABD
BCD
A B
C D

23. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Controlling fault tolerance: tunable consistency
23
Client - Consistency Level: How many replicas should
we check before acknowledgement?
CL = Quorum
Client
Toaster
Burst
Into
Flames!
Higher Consistency Level's Let us Make
Sure Events are Persisted
ACD
ABCABD
BCDACD
ABCABD
BCD
A B
C D

24. http://www.datastax.com/apache-cassandra-leads-nosql-benchmark
0
40000
80000
120000
160000
1 2 4 8
Performance

25. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Unparalleled durable performance
25
Par ReClu
Memory
Commit Log
Memtable Memtable
Disk
Memtable
Par ReClu
Par ReCluPar ReClu
Par ReCluPar ReClu
Par ReCluPar ReClu

26. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Unparalleled durable performance
26
Par ReClu
Memory
Commit Log
Memtable Memtable
Disk
Memtable
Par ReClu
Par ReCluPar ReClu
Par ReCluPar ReClu
Par ReCluPar ReClu
SSTable SSTable
Flushed

27. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Reading data is fast but limited by disk IO
27
Memory
Commit Log
Memtable Memtable
Disk
Memtable
Par ReCluPar ReClu
Par ReCluPar ReClu
Par ReCluPar ReClu
SSTable SSTable
Flushed
Replica

28. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Reading data is fast but limited by disk IO
28
Memory
Commit Log
Memtable Memtable
Disk
Memtable
Par ReCluPar ReClu
Par ReCluPar ReClu
Par ReCluPar ReClu
SSTable SSTable
Flushed
Replica
Par ReCluPar ReClu
Par ReCluPar ReClu

29. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Reading data is fast but limited by disk IO
29
Memory
Commit Log
Memtable Memtable
Disk
Memtable
Par ReCluPar ReClu
Par ReCluPar ReClu
Par ReCluPar ReClu
SSTable SSTable
Flushed
Replica
Par ReCluPar ReClu
Par ReCluPar ReCluLWW

30. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Data modeling for time series
30
Things Generating
Events

31. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Data modeling for time series
31
Things Generating
Events
Store Events ordered
by TimeUUID
t1 t2 t3 t4 t5 t6 t7 t8 t9

32. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Data modeling for time series
32
Things Generating
Events
Store Events ordered
by TimeUUID
t1 t2 t3 t4 t5 t6 t7 t8 t9
SSTable SSTable
t1 t10 t11 t20
Data Ends up being Stored
Temporally Sequentially on Disk
Additional tables with
Rollups/aggs etc …
With data stored sequentially by time,
time based queries become extremely fast!

33. Company Confidential© 2015 Aeris Communications, Inc. All Rights Reserved
© 2015 DataStax, All Rights Reserved.
Cassandra data modeling
33
Create Table example
( toasterID UUID, eventTime TIMEUUID, event Text, PRIMARY KEY (pk, ck))
Whole partition
available
on each replica
Data ordered within Partition by Clustering Key
Partition Key
Idle Toasting Toasting
Toast
Success!
Idle
12:00 12:01 12:02 12:03 12:04
Stored as
Multiple SSTables,
Each Internally Ordered
Easy to Search Ranges of Clustering Key
Difficult to search Ranges of Partition Key

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DataStax Spark-Cassandra connector
34
Receiver
DStream
Events
Batch Batch
RDD RDD RDD RDD
https://github.com/datastax/spark-cassandra-connector

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Streaming data direct to Cassandra
35
It's easier than ever to connect you
incoming event data with Cassandra

36. Start free Apache Cassandra training at DataStax Academy