Mar del Plata Summer Take Over Presentation 2016 - By Renato Carelli DevOps + Infra @ Big Data Hardening Enthusiast Cloud evangelist Bitcoin speculator

1. Empowering Big Data
with Cassandra

2. Empowering Big Data
with Cassandra

3. ./me
> Renato Carelli
- DevOps + Infra @ Big Data
- Hardening Enthusiast
- Cloud evangelist
- Bitcoin speculator

4. ./intro

5. ./intro/CAP
Consistency
Availability
Partition
tolerance
CA CP
AP
N/A

6. ./intro/RDBMS
Data

7. ./intro/NoSQL
Unstructured
(not really a DB)
Key Value Column Graph Document
General file
storage
Text files
Log files
Complex models
Flexible business
logic
Semi-structured
data
High volumes
OLAP
Analytics
NOT FOR
UPDATES
Relations between
entities (social
graphs)
Agile development
Flexible data-
models
Too many types.
Eg: Corporate
areas
Data Store BigQueryGFS BigTableCloudStore

8. ./intro/BigData

9. ./intro/specs

10. ./intro/history
BigTable (2006) Dynamo (2007)
Open Source
(2008)
{data modeling} {design}

11. ./intro/version_history
(0.1) (0.3) (0.6) (0.7)(0.8)(1.0) (1.1) (1.2) (2.0) (2.1)

12. ./infra

13. ./infra/features
N1
N2N4
N3
> Masterless
> Distributed
> Decentralized [p2p]
> Elastically Scalable
> Highly Available
> Fault-Tolerant
> Tuneable Consistent

14. ./infra/benchmark
Nodes
Ops/sec

15. ./infra/benchmark

16. ./infra/references
N1 C* Node
Connection
Failed
Connection
Established
Updated Data
Outdated Data
ACK
Slow Connection
Established

17. ./infra/token
Murmur3Partitioner:
-2^63 to +2^63 -1
token(‘Globant’) = -6148914691517517206

18. ./infra/token
DemoPartitioner:
1 to 100
token(‘Globant’) = 68

19. ./infra/token_ring
Node 1 Node 2
Node 3 Node 4

20. ./infra/token_ring
Node 1 Node 2
Node 3 Node 4
1 - 25
26 - 50
51 - 75 76 - 100
‘Glob’ = 17
‘ant’ = 94
‘Globant’ = 68
~/Images/pic.png = 69
~/media/movie.mkv = 34

21. ./infra/token_ring/replication
Node 1 Node 2
Node 3 Node 4
1 - 25 26 - 50
51 - 75 76 - 100
‘Glob’ = 17
RF = 3

22. ./infra/token_ring/vnodes
What about virtual nodes?
C* 1.2

23. ./infra/coordinator
N1
N2N4
N3

24. ./infra/coordinator
N1
N2N4
N3
> read
RF = 3
CL = TWO

25. ./infra/coordinator
N1
N2N4
N3
> read
RF = 3
CL = TWO

26. ./infra/coordinator
N1
N2N4
N3
Coordinator
> read
RF = 3
CL = TWO

27. ./infra/coordinator
N1
N2N4
N3
Coordinator
> read
RF = 3
CL = TWO

28. ./infra/coordinator
N1
N2N4
N3
Coordinator
> read
RF = 3
CL = TWO

29. ./infra/coordinator
N1
N2N4
N3
Coordinator
> read
RF = 3
CL = TWO

30. ./infra/coordinator
N1
N2N4
N3
Coordinator
> read
RF = 3
CL = TWO

31. ./infra/coordinator
N1
N2N4
N3
Coordinator
> read
RF = 3
CL = TWO

32. ./infra/replication
How many copies of each piece of data
(partition) do we want in the system?

33. ./infra/replication
> Replication Factor
> Replication Strategy
Keyspace-based!

34. ./infra/replication
N1
N2N4
N3RF = 3

35. ./infra/replication
CREATE KEYSPACE Globant
WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 3 };

36. ./infra/replication
N1
N2N3
N4
R1
R2
Data Center - East
N1
N2N3
N4
R1
R2
Data Center - West
RF = {‘w’:3, ‘e’:2}

37. ./infra/replication
CREATE KEYSPACE Globant
WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', 'w' : 3, 'e' : 2};

38. ./infra/consistency_level
How many replicas/nodes (based in RF) must
respond to declare success?

39. ./infra/consistency_level
Query-based!

40. ./infra/consistency_level
N1
N2N4
N3
> write
CL = QUORUM
CL = { ANY, ONE, TWO, THREE, QUORUM, LOCAL_ONE, LOCAL_QUORUM, EACH_QUORUM, ALL }

41. ./infra/consistency_level
N1
N2N4
N3
> read
CL = ALL
CL = { ANY, ONE, TWO, THREE, QUORUM, LOCAL_ONE, LOCAL_QUORUM, EACH_QUORUM, ALL }

42. ./infra/consistency_level
N1
N2N4
N3
> read
CL = QUORUM
CL = { ANY, ONE, TWO, THREE, QUORUM, LOCAL_ONE, LOCAL_QUORUM, EACH_QUORUM, ALL }

43. ./infra/consistency_level
Latest timestamp wins!

44. ./infra/consistency_level/immediate
{ R + W > RF }

45. ./infra/consistency_level/immediate
+Reads
> Write CL: ALL
> Read CL: ONE

46. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = ALL

47. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = ALL
> read
CL = ONE

48. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = ALL
> read
CL = ONE

49. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = ALL
> read
CL = ONE

50. ./infra/consistency_level/immediate
{ R + W > RF }

51. ./infra/consistency_level/immediate
{ 1 + 3 > 3 }

52. ./infra/consistency_level/immediate
+Writes
> Write CL: ONE
> Read CL: ALL

53. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = ONE

54. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = ONE
> read
CL = ALL

55. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = ONE
> read
CL = ALL

56. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = ONE
> read
CL = ALL

57. ./infra/consistency_level/immediate
{ R + W > RF }

58. ./infra/consistency_level/immediate
{ 3 + 1 > 3 }

59. ./infra/consistency_level/immediate
Balanced
> Write CL: QUORUM
> Read CL: QUORUM

60. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = QUORUM

61. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = QUORUM
> read
CL = QUORUM

62. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = QUORUM
> read
CL = QUORUM

63. ./infra/consistency_level/immediate
N1
N2N4
N3
RF = 3
> write
CL = QUORUM
> read
CL = QUORUM

64. ./infra/consistency_level/immediate
{ R + W > RF }

65. ./infra/consistency_level/immediate
{ 2 + 2 > 3 }

66. ./infra/read_repair
> Query ALL replicas when reading
- Data from one.
- Checksum + Timestamp from others.

67. ./infra/read_repair
> If there is a mismatch:
- Pull all data and merge
- Write back to out of sync replicas

68. ./infra/read_repair
Table-based!

69. ./infra/read_repair
N1
N2N4
N3
DATA
SUM
SUM

70. ./infra/read_repair
N1
N2N4
N3
DATA
SUM
SUM

71. ./infra/read_repair
N1
N2N4
N3

72. ./infra/read_repair
ALTER TABLE Globant.foobar
WITH read_repair_chance = 0.2;

73. ./infra/read_repair
> Weak Consistency
return results + repair
> Strong Consistency
repair + return results

74. ./infra/hinted_handoff
> Recovery mechanism
- Stored @ Coordinator‘s system.hints
- 3hs default TTL
- DataCenter-based!

75. ./infra/nodetool
$ nodetool repair
> Recovering a failed node
> Infreq read data (read repair chance)
> Tombstone gc period (gc_grace_seconds)

76. ./internals

77. ./internals/write_path
N
partition key 3 n: SasoConf city: cur year: 3
partition key 2 n: EkoParty city: caba year: 11
partition key 1 n: pwnConf city: mdq year: 2
MEMORY
STORAGE
Memtable (1 table)
Commit
Log
SSTables
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
C

78. ./internals/write_path
N
MEMORY
STORAGE
Memtable (1 table)
Commit
Log
SSTables
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
C
(Flush)
... ... ... ...
... ... ... ...
... ... ... ...
partition key 3 n: SasoConf city: cur year: 3
partition key 2 n: EkoParty city: caba year: 11
partition key 1 n: pwnConf city: mdq year: 2

79. ./internals/write_path
N
MEMORY
STORAGE
Memtable (1 table)
Commit
Log
SSTables
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
C
... ... ... ...
... ... ... ...
... ... ... ...
partition key 3 n: SasoConf city: cur year: 3
partition key 2 n: EkoParty city: caba year: 11
partition key 1 n: pwnConf city: mdq year: 2
Compaction
... ... ... ...
... ... ... ...
... ... ... ...

80. ./internals/write_path
N
MEMORY
STORAGE
Memtable (1 table)
Commit
Log
SSTables
C
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
... ... ... ...
Compaction
... ... ... ...
... ... ... ...
... ... ... ...

81. ./hands-on

82. ./hands-on/stress
> 1.3M writes/sec (1.3 write/µs)
> 160K reads/sec (160 reads/ms)
> Collisions?

83. ./hands-on/stress
Custom Apps

84. ./me/contact
> Renato Carelli
- mailto: renato.carelli@globant.com
- mailto: renato@carelli.com.ar
- telegram: @renato

85. We are hiring DevOps!
> mailto: solange.domijan@globant.com

86. Thanks!