scaling datastax in docker

Joel JacobsonScaling DataStax in Docker

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How it started

Internal project at dotCloud

Pivoted to Docker Inc.

Execution using libcontainer

Huge adoption

What is Docker?and why is it important?

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3 key concepts

Images

Registries

Containers

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Example Dockerfile image

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Why are containers important?Speeding up application development

Better resource utilization

Mobility

Faster provisioning

Microservices

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Why are containers important?

WEB UI BILLINGCUSTOMER

MYSQL

EXT SERVICE

DB ADAPTER

PAYMENTS

SERVICE X

SERVICE YREST API

EXT SERVICE

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Why are containers important?WEB UI

BILLINGREST API

CUSTOMERREST API

CASSANDRA SPARKSOLR

PAYMENTSREST API

SERVICE XREST API

SERVICE YREST API

EXT SERVICEEXT SERVICE

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Why are containers important?

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Why are containers important?

DataStax Enterprise in Docker

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Why are containers important?

Build once, deploy anywhere

Flexibility for sharing binaries and libraries across applications

Process of managing, maintaing and deploying turn key

Officially supported since DSE 4.8

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DSE processesCore DSE JVM

One or more Spark executor processes

Single Spark worker process

Multiple processes for the Hadoop stack

Ad-hoc process (Spark job server, SparkSQL, CLI etc.)

OpsCenter agent

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DataStax Enterprise configuration

Cassandra configuration (seeds, cluster_name etc)

Where to manage Cassandra data

Optimal JVM heap size

Optimal garbage collector

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DataStax Enterprise configuration

Default capability limits of Docker break mlockall

Add –XX:+AlwaysPreTouch to the JVM arguments

ulimits inherited from Docker daemon

Disable swap on host OS

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Networking

Default networking (via Linux bridge) not recommended

Instead use docker run –net=host

Use pipework or weave for consistent IP addresses

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Storage

Everything in /var/lib/cassandra;

commitlog

saved_caches

data directories

Use supported filesystem

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Storage

Data volumes can be shared and reused amoung containers

Changes are made directly

Changes to a volume will not be included when you update an image

Data volumes persist if container is deleted

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Storage

docker run –v <some root dir>/<dse_image_name>-data:/data –v <some root dir>/<dse_image_name>-conf:/conf –v <some root dir>/<dse_image_name>-logs:/logs –d <dse_image_name>

DSE Docker Demo

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Futures

Splitting up DSE processes into separate containers

Integration with Kubernetes, Mesos

Deployment model on public/private clouds

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SummaryConfigure OS and JVM

Map storage volumes

Avoid bridge/NAT networking

Test. Test. Test.

Useful Information

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Links and informationDatastax.com

http://www.datastax.com/wp-content/uploads/resources/DataStax-WP-Best_Practices_Running_DSE_Within_Docker.pdf

github.com/joeljacobson/dse-docker

academy.datastax.com

Thank you