This document discusses Elassandra, which combines Elasticsearch and Cassandra to provide search capabilities within Cassandra. It maps concepts between Elasticsearch and Cassandra, describes chaos testing by taking nodes down and performance testing. Performance tests showed some degradation using Cassandra but acceptable, and Elasticsearch performance was 50% lower than standalone Elasticsearch but workarounds exist. Throughput improved up to 50% from version 2.1.1 to 2.4.2.

1. Elassandra
Diego Pacheco

2. @diego_pacheco
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3. Cassandra: Great! But there is no real search capability.

4. ES: Loose DATA! Can't be used as Source of Truth.

5. Elassandra
+

6. Elassandra = ES Search in Cassandra

7. Elassandra Concepts mapping
Elasticsearch Cassandra
Mapping Schema
Cluster Virtual DC
Index Keyspace
Type Table
Document Row
Field Column
Object Nested Field User Defined Type

8. Elassandra Chaos
Elassandra Cluster
Node 1 Node 2
NDbench

9. Elassandra Chaos - Strategy
❏ Via Cassandra API (Reads/Writes)
❏ Test 1. Tear Down node 2 -> Keep node 1 up
❏ Test 2. Tear Down node 1 -> Them put it up after 10s
❏ Via ES API (Reads/Writes)
❏ Test 1. Tear Down node 2 -> Keep node 1 up
❏ Test 2. Tear Down node 1 -> Them put it up after 10s

10. Elassandra Chaos - Results - Reads

11. Elassandra Chaos - Results - Reads

12. Elassandra Chaos - Results - Reads

13. Elassandra Chaos - Results - Writes

14. Elassandra Performance - versions
2.2.8
2.1.1
2.1.1-18 on CASS 2.2.8
NDBench
2.2.2
Master
(github)
ORACLE JDK 8_u45
2.4.2 on CASS 2.2.8

15. Elassandra Performance - ELA and ES
CLUSTER
CLUSTER

16. Elassandra Performance - ELA and CASS
CLUSTER
CLUSTER
NDBench
NDBench

17. Elassandra Performance - Results - the surprise!
Hardware Memoria CPU
m4.4xlarge 64 GB 16 vCPU
2.2.8
2.1.1
2.1.1-18 on CASS 2.2.8
Reads 28k
Writes 121k
Reads 20k
Writes 2k
Reads 24k
Writes 97k
Reads 3k
Writes 5k

18. Elassandra Performance - Results - Details!
2.1.1 2.1.1-18 on CASS 2.2.8
Read ALL 21k
Read Get ID 59k
Read Search ID 15k
Read ALL 3k
Read Get ID 17k
Read Search ID 3k

19. Elassandra Performance - Results - tuning!
2.1.1-18 on CASS 2.2.8
Read ALL OK 3k
Read ALL KO 4k
Threadpool.index.queue_size = 10k
Threadpool.index.queue_size = 1k (default)
Read ALL OK 5k
Read ALL KO 6k

20. Elassandra Performance - Results - 2.4.2!
2.4.2 on CASS 2.2.8
Read ALL OK 12k
Read ALL KO 13k

21. Elassandra ES Reads - 12k OK
Hardware Memoria CPU
m4.4xlarge 64 GB 16 vCPU

22. ELA ES READ 12k Search CASS JAVASTATS

23. ELA ES READ 12k Search CASS Nodes

24. ELA ES READ 12k Search ES

25. ELA ES READ 12k Search ES NODE

26. ELA ES READ 12k Search GATLING OS

27. Conclusions
❏ Performance has some minor degradation with CASS but is acceptable.
❏ ES performance still 50% less than original elasticsearch but you can manage to workaround.
❏ Tests was run on 4th JAN 2017 from 12:00 to 17:00 BRT
❏ CPU CASS Improvement from 1500% to 500%
❏ Up to 50% Throughput improvement from 2.1.1 to 2.4.2 (5k to 12k)
❏ OS Used was Amazon Linux (CentOS Based)
❏ All Boxes was Optimized in sense on Open Files (65k) and Gatling TCP Settings
https://gist.github.com/diegopacheco/31091f9c507b9c78128e73b48f2ce08a

28. Elassandra
Diego Pacheco