Top 10 Best Practices for Apache Cassandra and DataStax Enterprise

academy.datastax.com | @jscarp
DataStax
Top 10 Best Practices
1 © DataStax, All Rights Reserved.

DataStax Top 10 Best Practices
• Thanks to DataStax Professional
Services
• Related post:
https://academy.datastax.com/top10best
practices
2 © DataStax, All Rights Reserved. academy.datastax.com | @jscarp

Why we ❤️ Apache Cassandra
• Distributed, decentralized
• Elastic scalability
– add/remove nodes with no downtime
• High performance
• High availability / fault tolerant
– no single point of failure
• How do we realize these benefits?

1. Know your access
patterns

Relational vs. Cassandra Data Modeling
• Relational Approach • Cassandra Approach
Data
Models
Application Data
Models
Application

KillrVideo Reference Application

Application Workflow in KillrVideo
7 © DataStax, All Rights Reserved. academy.datastax.com | @jscarp7
User Logs
into site
Show basic
information
about user
Show videos
added by a
user
Show
comments
posted by a
user
Search for a
video by tag
Show latest
videos added
to the site
Show
comments
for a video
Show ratings
for a video
Show video
and its
details

Take the KillrVideo Tour

2. Get your data model
right

Relational Modeling
• Create entity table
• Add constraints
• Index fields
• Foreign Key relationships
• SQL != CQL
11
CREATE TABLE users (
id number(12) NOT NULL ,
firstname nvarchar2(25) NOT NULL ,
lastname nvarchar2(25) NOT NULL,
email nvarchar2(50) NOT NULL,
password nvarchar2(255) NOT NULL,
created_date timestamp(6),
PRIMARY KEY (id),
CONSTRAINT email_uq UNIQUE (email)
);
-- Users by email address index
CREATE INDEX idx_users_email ON users (email);
CREATE TABLE videos (
id number(12),
userid number(12) NOT NULL,
name nvarchar2(255),
description nvarchar2(500),
location nvarchar2(255),
location_type int,
added_date timestamp,
CONSTRAINT users_userid_fk
FOREIGN KEY (userid)
REFERENCES users (Id) ON DELETE CASCADE,
PRIMARY KEY (id)
);

Queries in KillrVideo to Support Workflows
Users
User Logs into
site
Find user by email
address
Show basic
information
about user
Find user by id
Comments
Show
comments for
a video
Find comments by
video (latest first)
Show
comments
posted by a
user
Find comments by
user (latest first)
Ratings
Show ratings
for a video Find ratings by video

Designing Tables Based on Queries
Show video
and its
details
Find video by id
Show videos
added by a
user
Find videos by user (latest
first)
CREATE TABLE videos (
videoid uuid,
userid uuid,
name text,
description text,
location text,
location_type int,
preview_image_location text,
tags set<text>,
PRIMARY KEY (videoid)
);
CREATE TABLE user_videos (
userid uuid,
videoid uuid,
name text,
PRIMARY KEY (userid,
added_date, videoid)
)
WITH CLUSTERING ORDER BY (
added_date DESC,
videoid ASC);

Designing for fast access
CREATE TABLE user_videos (
userid uuid,
videoid uuid,
name text,
PRIMARY KEY (userid,
added_date, videoid)
)
WITH CLUSTERING ORDER BY (
added_date DESC,
videoid ASC);
Partition key –
which node(s)
Clustering columns –
layout on disk
…uniqueness

Data Modeling Best Practices
• Table per query
• Use denormalization to minimize
number of queries required
• Make sure primary key guarantees
uniqueness
• Use bucketing to break up large
partitions
• Highly recommended: DS220: Practical
Application Data Modeling with Apache
Cassandra

3. Avoid tombstones

Deletion and Tombstones
• Append-only storage model – SSTables are immutable
• Tombstones used to explicitly indicate deleted data
– Prevent accidental restoration of deleted data
• Data actually cleaned up during compaction
• Large numbers of tombstones can affect reads
– Example log output
Read 1 live and 123780 tombstoned cells | 19:48:36,710 | 127.0.0.1 | 128631

Avoid Deletes and Writing Nulls
VS
INSERT INTO myTable (primary_key, clustering_key)
VALUES ('pk1', 'ck1');
INSERT INTO myTable (primary_key, clustering_key, regular_col)
VALUES ('pk1', 'ck1', null);
⇒ Second version writes a tombstone

Tombstones - Mitigating
• Use a journal-style data model
• Set time to live (TTL)
• Delete the largest possible amount of data at once
– Range delete > Partition delete > row delete > cell delete > collection item delete
• http://thelastpickle.com/blog/2016/07/27/about-deletes-and-tombstones.html
• https://academy.datastax.com/support-blog/cleaning-tombstones-datastax-dse-and-
apache-cassandra
• https://academy.datastax.com/units/compaction-compaction-and-tombstones

4. Know your drivers

DataStax Drivers
• OSS Cassandra Drivers
– CQL Support
– Sync / Async API
– Load Balancing
– Auto Node Discovery
– Object Mapper
© DataStax, All Rights Reserved.
• DataStax Enterprise Drivers
– OSS Driver features plus...
– Unified Authentication
– Graph Fluent API
– Geometric Types
21
• ODBC
• JDBC
@DataStaxAcademy #DataStaxDeveloperDay

Driver Documentation
22 © DataStax, All Rights Reserved. Confidential
Apache Cassandra Drivers (Open
Source)
DataStax Drivers (DataStax
Enterprise)
DataStax Java Driver DataStax Enterprise Java Driver
DataStax Python Driver DataStax Enterprise Python Driver
DataStax Node.js Driver DataStax Enterprise Node.js Driver
DataStax Ruby Driver DataStax Enterprise Ruby Driver
DataStax C# Driver DataStax Enterprise C# Driver
DataStax C/C++ Driver DataStax Enterprise C/C++ Driver
DataStax PHP Driver DataStax Enterprise PHP Driver

DataStax Driver Tips and Tricks
• Common features:
– Connection management
– Creating and executing statements, and
accessing the results
– Synchronous and asynchronous execution
– Object mapping
– Logging and metrics
– Policy management
– Threading, networking and resource
management
– Schema access / management
• Tips
– Load balancing policy
– Retry policy
– Connection pool settings
– Asynchronous operations
• Coming soon: Getting Started with
Drivers quick courses on DataStax
Academy

5. Plan for and practice
operations

Do you have a Run Book?
• Installation
• Upgrade
• Scaling up
• Scaling down
• Node replacement
• Repairs
• Backup
• Restore
• Monitoring
• Tuning

OpsCenter
• Browser-based DSE cluster tool for:
– Configuring
– Monitoring
– Managing
• Two major components tied together:
– OpsCenter Monitoring - monitoring and management
– Life Cycle Manager (LCM) - mostly configuration and deployment

@DataStaxAcademy #DataStaxDeveloperDay© DataStax, All Rights Reserved.
Start with Security
• End to end encryption
• Data auditing
• LDAP integration
• Kerberos integration
• Role based access control
• Row-level access control
Bad security results in data breaches. DSE has a number of features that can be used to
secure your data at all stages.
© DataStax, All Rights Reserved.27

6. Do performance
testing

Performance Testing Tips
• Use your actual data model and realistic
test data
• Measure against SLAs
– 99th percentile
• Happy path and error / load conditions
• Automate using Cassandra Stress,
Gatling
• Incorporate performance monitoring into
operations

OpsCenter Performance Service
• Want to know when your nodes are slowing down? We'll send you a message
• DSE will monitor your queries
• Slow queries? Will let you know what's going on

DSE 6.7 - Monitoring with Prometheus and Grafana

Sample Grafana Dashboard

7. Automate cluster
management

OpsCenter Lifecycle Manager (LCM)
• Run jobs
– Installation
– Configuration
– Upgrade

Automate Monitoring and Management
• Use Lifecycle Manager
API to automate actions
• Puppet, Chef, Ansible,
Terraform, etc.
https://docs.datastax.com/en/opscenter/6.7/
opsc/opscApi_g.html

8. Understand how DSE
features can help

DSE Search: Apache Solr / Lucene + Cassandra
• Supports ad-hoc queries not supported
by Cassandra
• Full text search, Faceting, Stemming
• Geospatial Search
• Live indexing engine
• No separate search cluster
• No ETL or sync to build and maintain
• Search indexes co-located with
Cassandra
Search-enabled
Data Center
• Search-enabled CQL
• Search index creation via CQL

DSE Analytics: Spark + Cassandra
• Spark goodness: Spark Streaming,
Spark SQL, Spark ML
• Perform analytics without ETL to
separate cluster
• Write analytic results back to operational
DB with Spark-Cassandra connector
• Distributed file system (DSEFS)
Co-located Spark with Cassandra
Analytics
Data Center
• Data validation
• Migrate data to new schema

DSE Graph: Cassandra + Apache TinkerPop
• Scalable, distributed graph DB
• Optimized for storing, traversing, and
querying
• DSE Analytics and DSE Search
integrated
• Use cases: Customer 360,
Recommendations, Fraud Detection
• Use when the relationships between the
entities are the most important part

DataStax Studio
• Notebook style interface
• CQL, Gremlin, Spark SQL
• Data visualization
• Auto-completion
• Rapid prototyping & collaboration
• Query tracing

DSBulk – Bulk Data Loading
• Moves Cassandra data to/from files in
the file system
• Uses both CSV or JSON formats
• Command-line interface

9. Know where to find
helpful resources

DataStax Academy
• Free self-paced courses
• DS201: Apache Cassandra™
• DS210: Operations
• DS220: Data Modeling
• DS310: Search
• DS320: Analytics
• DS330: Graph
• DS332: Graph Analytics (NEW)
https://academy.datastax.com

Learning Paths on DataStax Academy
https://academy.datastax.com/paths

Live Coding on Twitch
• Live coding sessions with advocates and
guests
• Working through the challenges of
building distributed systems
• Join the conversation and ask questions
• Some advocates also do streaming on
personal channels
https://www.twitch.tv/datastaxacademy

Distributed Data Show
• Interview-style show featuring a mix of
DataStax and industry guests
• We go in-depth on the technology and
challenges of data in large-scale
distributed systems
• Released weekly on DataStax
Academy YouTube channel and as a
podcast
• Send us your suggestions for topics
and guests – we love customer use
cases
46 academy.datastax.com | @jscarp© DataStax, All Rights Reserved.

Where are we online?
Engage!
– YouTube Channel
– Twitter - @DataStaxAcademy
– LinkedIn
– KillrVideo reference application
– DataStax Academy Slack

DataStax Learning Events
• Cassandra Days
• DataStax Developer Days
• Meetups
• Accelerate Conference
http://academy.datastax.com/events

Join us at Accelerate!
http://www.datastax.com/accelerate
Discount Code: ADVOCATE20

10. Engage DataStax
Professional Services

DataStax Customer Success
Helping Customers Get The Most Out of Their Investment
ACCELERATE
TIME TO VALUE
MITIGATE RISK
AND REALIZE
VALUE
IMPROVE ADOPTION
AND PRODUCTIVITY
SERVICES
TRAINING
CUSTOMER
SUCCESS
Our Customer Success team helps you with your implementation, training, adoption and operational support crucial to your success

Questions?

Thank you

Top 10 Best Practices for Apache Cassandra and DataStax Enterprise

More Related Content

What's hot

Similar to Top 10 Best Practices for Apache Cassandra and DataStax Enterprise

More from DataStax

Recently uploaded

Top 10 Best Practices for Apache Cassandra and DataStax Enterprise