Everybody wants to go on the “Big Data” hype cycle, “To do Scale”, to use the coolest tools in the market like Hadoop, Apache Spark, Apache Cassandra, etc. But do they ask themselves is there really a reason for that? In the talk we’ll make a brief overview to all of the technologies in the Big Data world nowadays and we’ll talk about the problems that really emerge when you’d like to enter the great world of Big Data handling. Showing you the Hadoop ecosystem and Apache Spark and all of the distributed tools leading the market today, will give you all a notion of what will be the real costs entering that world. Promise that I’ll share some stories from the trenches :) (And about the “pool” thing...I don’t really know how to swim)

1. Quick dive into the
Big Data pool
without drowning
Demi Ben-Ari - VP R&D @ Panorays

2. About Me
Demi Ben-Ari, Co-Founder & VP R&D @ Panorays
● BS’c Computer Science – Academic College Tel-Aviv Yaffo
● Co-Founder “Big Things” Big Data Community
In the Past:
● Sr. Data Engineer - Windward
● Team Leader & Sr. Java Software Engineer,
Missile defense and Alert System - “Ofek” – IAF
Interested in almost every kind of technology – A True Geek

3. Agenda
● Basic Concepts
● Introduction to Big Data frameworks
● Distributed Systems => Problems
● Monitoring
● Conclusions

4. Say “Distributed”, Say “Big Data”,
Say….

5. Some basic concepts

6. What is Big Data (IMHO)?
● Systems involving the “3 Vs”:
What are the right questions we want to ask?
○ Volume - How much?
○ Velocity - How fast?
○ Variety - What kind? (Difference)

7. What is Big Data (IMHO)
● Some define it the “7 Vs”
○ Variability (constantly changing)
○ Veracity (accuracy)
○ Visualization
○ Value

8. What is Big Data (IMHO)
● Characteristics
○ Multi-region availability
○ Very fast and reliable response
○ No single point of failure

9. Why Not Relational Data
● Relational Model Provides
○ Normalized table schema
○ Cross table joins
○ ACID compliance (Atomicity, Consistency, Isolation, Durability)
● But at very high cost
○ Big Data table joins - bilions of rows - massive overhead
○ Sharding tables across systems is complex and fragile
● Modern applications have different priorities
○ Needs for speed and availability come over consistency
○ Commodity servers racks trump massive high-end systems
○ Real world need for transactional guarantees is limited

10. What strategies help manage Big Data?
● Distribute data across nodes
○ Replication
● Relax consistency requirements
● Relax schema requirements
● Optimize data to suit actual needs

11. What is the NoSQL landscape?
● 4 broad classes of non-relational databases (DB-Engines)
○ Graph: data elements each relate to N others in graph / network
○ Key-Value: keys map to arbitrary values of any data type
○ Document: document sets (JSON) queryable in whole or part
○ Wide column Store (Column Family): keys mapped to sets of
n-numbers of typed columns
● Three key factors to help understand the subject
○ Consistency: Get identical results, regardless which node is queried?
○ Availability: Respond to very high read and write volumes?
○ Partition tolerance: Still available when part of it is down?

12. What is the CAP theorem?
● In distributed systems, consistency, availability and partition tolerance exist in
a manually dependant relationship, Pick any two.
Availability
Partition toleranceConsistency
MySQL, PostgreSQL,
Greenplum, Vertica,
Neo4J
Cassandra,
DynamoDB, Riak,
CouchDB, Voldemort
HBase, MongoDB, Redis, BigTable, BerkeleyDB
Graph
Key-Value
Wide Column
RDBMS

13. DB Engines - Comparison
● http://db-engines.com/en/ranking

14. DB Engines - Comparison

15. What does DevOps really mean?
Development
Software Engineering
UX
Operations
System Admin
Database Admin

16. What does DevOps really mean?
DevOps
Cross-functional teams
Operators automating systems
Developers operating systems

17. Introduction to
Big Data
Frameworks
https://d152j5tfobgaot.cloudfront.net/wp-content/uploads/2015/02/yourstory_BigData.jpg

18. Characteristics of Hadoop
● A system to process very large amounts of unstructured and complex
data with wanted speed
● A system to run on a large amount of machines that don’t share any
memory or disk
● A system to run on a cluster of machines which can put together in
relatively lower cost and easier maintenance

19. Hadoop Principals
● “A system to move the computation, where the data is”
● Key Concepts of Hadoop
Flexibility Scalability
Low cost
Fault
Tolerant

20. Hadoop Core Components
● HDFS - Hadoop Distributed File System
○ Provides a distributed data storage system to store data in smaller
blocks in a fail safe manner
● MapReduce - Programming framework
○ Has the ability to take a query over a dataset, divide it and run in in
parallel on multiple nodes
● YARN - (Yet Another Resource Negotiator) MRv2
○ Splitting a MapReduce Job Tracker’s info
■ Resource Manager (Global)
■ Application Manager (Per application)

21. Hadoop Ecosystem
Hadoop Core
HDFS
MapReduce /
YARN
Hadoop Common
Hadoop Applications
Hive Pig HBase Oozie Zookeeper Sqoop Spark

22. Hadoop (+Spark) Distributions
Elastic MapReduce DataProc

23. New Age BI Applications
● Able to understand various types of data
● Ability to clean the data
● Process data with applied rules locally and in distributed environment
● Visualize sizeable data with speed
● Extend results by sharing within the enterprise

24. Big Data Analytics
● Processing large amounts of data without data movement
● Avoid data connectors if possible (run natively)
● Ability to understand vast amount of data types and and data
compressions
● Ability to process data on variety of processing frameworks
● Distributed data processing
○ In-Memory a big plus
● Super fast visualization
○ In-Memory a big plus

25. When to choose hadoop?
● Large volumes of data to store and process
● Semi-Structured or Unstructured data
● Data is not well categorized
● Data contains a lot of redundancy
● Data arrives in streams or large batches
● Complex batch jobs arriving in parallel
● You don’t know how the data might be useful

26. Distributed Systems => Problems
https://imgflip.com/i/1ap5kr
http://kingofwallpapers.com/otter/otter-004.jpg

27. Monolith Structure
OS CPU Memory Disk
Processes Java
Application
Server
Database
Web Server
Load
Balancer
Users - Other Applications
Monitoring
System
UI
Many times...all of this was on a single physical server!

28. Distributed Microservices Architecture
Service A
Queue
DB
Service B
DBCache
Cache DBService C
Web
Server
DB
Analytics Cluster
Master
Slave Slave Slave
Monitoring System???

29. MongoDB + Spark
Worker 1
Worker 2
….
….
…
…
Worker N
Spark
Cluster
Master
Write
Read
MasterSahrded
MongoDB
Replica Set

30. Cassandra + Spark
Worker 1
Worker 2
….
….
…
…
Worker N
Cassandra
Cluster
Spark
Cluster
Write
Read

31. Cassandra + Serving
Cassandra
Cluster
Write
Read
UI Client
UI Client
UI Client
UI Client
Web
ServiceWeb
ServiceWeb
ServiceWeb
Service

32. Problems
● Multiple physical servers
● Multiple logical services
● Want Scaling => More Servers
● Even if you had all of the metrics
○ You’ll have an overflow of the data
● Your monitoring becomes a “Big Data” problem itself

33. This is what “Distributed” really Means
The DevOps Guy
(It might be you)

34. Monitoring is Crucial
http://memeguy.com/photo/46871/you-are-being-monitored

35. Monitoring
Operation System
Metrics

36. Some help
from “the Cloud”

37. AWS’s CloudWatch / GCP StackDriver

38. Report to Where?
● We chose:
● Graphite (InfluxDB) + Grafana
● Can correlate System and
Application metrics in one
place :)

39. Monitoring
Cassandra

40. Monitoring Cassandra
● OpsCenter - by DataStax

41. Monitoring Cassandra

42. Monitoring Spark

43. Ways to Monitoring Spark
● Grafana-spark-dashboards
○ Blog:
http://www.hammerlab.org/2015/02/27/monitoring-spark-with-graphite-and-grafana/
● Spark UI - Online on each application running
● Spark History Server - Offline (After application finishes)
● Spark REST API
○ Querying via inner tools to do ad-hoc monitoring
● Back to the basics: dstat, iostat, iotop, jstack
● Blog post by Tzach Zohar - “Tips from the Trenches”

44. Monitoring
Your Data
https://memegenerator.net/instance/53617544

45. Data Questions? What should be measure
● Did all of the computation occur?
○ Are there any data layers missing?
● How much data do we have? (Volume)
● Is all of the data in the Database?
● Data Quality Assurance

46. Data Answers!
● The method doesn’t really matter, as long as you:
○ Can follow the results over time
○ Know what your data flow, know what might fail
○ It’s easy for anyone to add more monitoring
(For the ones that add the new data each time…)
○ It don’t trust others to add monitoring
(It will always end up the DevOps’s “fault” -> No monitoring will be
applied)

47. Logging?
Monitoring?
https://lh4.googleusercontent.com/DFVcH-E5XKj8cbhEtI0qabmf_wwVqWWvk0pK5H5rnC_kVxY2tXClKfzV-LvAH61YRLJUEvtO9amjWfjcY4Z57VBYCuQ9
5_hdAVEHgLAuepJiArH0wJERWuzzmgnPysCiIA

48. ELK - Elasticsearch + Logstash + Kibana
http://www.digitalgov.gov/2014/05/07/analyzing-search-data-in-real-time-to-drive-decisions/

49. Monitoring Stack
Alerting
Metrics Collection
Datastore
Dashboard
Data Monitoring
Log Monitoring

50. Big Data - Are we there yet?
● “3 Vs”: - What are the right questions we want to ask?
○ Volume - How much?
■ Can it run on a single machine in reasonable time?
○ Velocity - How fast?
■ Can a single machine handle the throughput?
○ Variety - What kind? (Difference)
■ Is your data not changing and varying?
● If the answer for most of the previous questions is “Yes”?
Think again if you want to add the complexity of “Big Data”

51. Conclusions
● Think carefully before going into the “Big Data pool”
○ See if you really have a problem that you’re trying to solve
○ It’s not a silver bullet
● Take measures to automate and monitor everything
● Having Clusters and distributed frameworks will cost a lot - eventually
● Fit your storage layer(s) to the needs

52. Questions?
https://www.stayathomemum.com.au/wp-content/uploads/2015/01/DDDDDD.jpg
Still feel like you’re
drowning?

53. ● LinkedIn
● Twitter: @demibenari
● Blog:
http://progexc.blogspot.com/
● demi.benari@gmail.com
● “Big Things” Community
Meetup, YouTube, Facebook,
Twitter
● GDG Cloud