This document discusses using Apache Cassandra to solve the problem of distributed data across hybrid cloud environments. It begins by describing the distributed data problem, including having applications and data in multiple geographic regions. It then discusses using Cassandra on-premise, in public clouds, and across multiple public clouds. The document provides an example of defining Cassandra keyspaces that replicate across data centers in different cloud regions. It concludes by discussing how to configure Cassandra to recognize multiple logical data centers spanning on-premise and cloud environments.

1. Solving Hybrid Cloud Data
Replication with Apache Cassandra
Aaron Ploetz
September 15, 2021

2. Agenda
● Distributed Data Problem
● On-Prem
● Public Cloud
● Multiple Public Clouds
● Execution
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3. The
Distributed Data
Problem
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4. The Distributed Data Problem
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● Many applications and services.
● Multiple geographic regions.
● Data needs to be:
● Close to the application
● Highly Available
● Consistent
Mobile App
Web App
...well, eventually

5. % whoami_
Aaron Ploetz
● Product Manager at DataStax
● MVP for Apache Cassandra (2014-2017)
● DB Engineer in retail space (former)
● Author:
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6. How to solve?
Apache Cassandra
● Distributed Row Store
● Top-level Apache Project
● Current GA version 4.0.1
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7. Why Apache Cassandra?
Features
● High Availability
● Data center awareness
● Nodes are peers
● Designed to handle failures
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X
X
X

8. On-Premise

9. On-premise?
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● Many large enterprises still deploy on-prem:
● Private cloud
● Kubernetes
● Bare metal

10. Cassandra on-premise
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Data Center
Applications
Databases
Infrastructure API

11. Public Cloud

12. Why public cloud?
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● Gets data in close proximity to:
● Customers
● Application
?

13. Cassandra in the public cloud
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Applications
Databases
Infrastructure API
Applications
Databases
West East

14. GCP example
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Applications
Databases
Infrastructure API
Applications
Databases
US-Central1 US-East1
Data Center(s)
Applications
Databases
On-prem

15. Multi-
Public Cloud

16. Why multi-public cloud?
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● Ensures uptime through outages.
● Leverage for better rates.
Two or
More?
Why not?

17. Major provider outages?
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18. Multi-Cloud example
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Applications
Databases
Infrastructure API
Applications
Databases
US-East1 East-US-2
Data Center(s)
Applications
Databases
On-prem

19. Execution

20. Logical data centers
cassandra.yaml
endpoint_snitch: GossipingPropertyFileSnitch
cassandra-rackdc.properties
dc=us-east Region
rack=us-east-2a Availability Zone (AZ)*
*Note: AZs == RF 20

21. Keyspace definition
CREATE KEYSPACE pricing WITH REPLICATION=
{"class":"NetworkTopologyStrategy",
"us-west":"3","us-east":"3"};
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22. Keyspace definition
CREATE KEYSPACE pricing WITH REPLICATION=
{"class":"NetworkTopologyStrategy",
"us-west":"3","us-east":"3",
"milwaukee-dc":"3","omaha-dc":"3"};
Data center names here must match names in
cassandra-rackdc.properties!
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23. Different ways to run Cassandra
● Apache Cassandra
● Free and open source
● Runs on commodity hardware
● K8ssandra
● Free and open source
● Cassandra designed to run on K8s
● DataStax Astra DB
● Serverless, cloud native
● No painful DevOps
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24. Questions?
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