DEPLOYING A DOCKERIZED DISTRIBUTED APPLICATION TO MESOS

Julia Mateo

DEPLOYING A DOCKERIZED DISTRIBUTED APPLICATION IN MESOS

Julia Mateo

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Who am I

• Java developer and tech lead at Hortis GRC (Geneva, Switzerland)

• Team jDuchess Swiss

@juliamateodc@duchessswiss http://jduchess.ch/

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Summary

• Mesos… what is it?

• Docker

• A Mesos framework : Marathon

• Deploying a distributed app in Mesos

• Service Discovery

• Load balancing

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Mesos... what is it?

Deployment system

Execution platform

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Mesos... what is it?

• Deployment system :

• Mesos : smart deployment system

• Ansible, Chef, Puppet… static configuration

• Mesos dynamically allocates resources depending on cluster load (or other external factors)

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Mesos... what is it?

• Execution platform

• Hosting high level applications

• More flexibility :

• If one slave crashes, app is deployed in new instance (Marathon)

• HAProxy for load balancing

• Alternative to paying third party Paas solutions (Heroku, Azure, Openshift…)

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Mesos... what is it?

• Abstraction of cluster resources

• Share resources across multiple frameworks (versions of the same framework)

• Resource fair sharing : alternative to static partitioning

• Data locality

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ZKMaster Master

Executor

ExecutorSlaves

Executor Executor

Executor Executor

Executor Executor Executor

Mesos

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http://mesos.apache.org/documentation/latest/mesos-architecture/

Mesos

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From https://www.docker.com/whatisdocker/

• Docker is an open platform for developers and sysadmins to build, ship, and run distributed applications.

DOCKER

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ServerHost OS

Hypervisor

GuestOS

Guest OS

Guest OS

Guest OS

Libs/ Libs/ Libs/

App 1 App 2 App 3 App 4

Libs/

ServerHost OS

Docker Engine

Libs/Bins Libs/

App 1 App 2 App 3 App 4c1 c2 c3 c4

VM1VM2VM3VM4

Docker

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Docker Images Docker

Images

libcontainer, Union Filesystem

Centos Ubuntu

Jetty

add App.war

Container 1

OracleDB

Container 2

Read only

WritableWritable

Read only

Containers and images

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• Marathon is a Mesos framework written in Scala

• Provides easy deployment of Docker containers

• Management of long running apps

• Rest API for developers

Marathon

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ZKMaster Master

Executor

ExecutorSlaves

Executor Executor

Executor Executor

Executor Executor Executor

Mesos

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ZKMaster Master

Executor

ExecutorSlaves

Executor Executor

Executor Executor

Executor Executor Executor

Mesos

Marathon

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Demo

• cm-voting

• Infrastructure

• Mesos UI

• Marathon UI

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The infrastructure

Io

Europa

Ganymede

Callisto

JupiterMesos master

Mesos slave

Mesos slave

Mesos slave

Mesos slave

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Service discovery

cm-voting

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Mesos slave 1

Mesos slave 2

Service discovery

cm-voting

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Mesos slave 2

Mesos slave 1

Service discovery

cm-votingIP ?

PORT ?

CREDENTIALS ??

Mesos slave 2

Mesos slave 1

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cm-voting

Mesos slave 1

Mesos slave 2

REPLICATION, LOAD BALANCING...

Service discovery

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Service discovery

cm-voting

... AND FAILOVER

Mesos slave 1

Mesos slave 2

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Service discovery with MesosDNS

https://github.com/mesosphere/mesos-dns

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Demo

• Deploy MesosDNS

• Deploy Mongo

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lb-marathon

• Tool for managing HAProxy

• It subscribes to Marathon’s event bus

• Updates the HAProxy configuration in real time

• Health checking

• SSL support

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• Deploy 2 instances of cm-voting

• Add external proxy and load balancer : lb-marathon

Demo

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MesosDNS : Service discoveryDOES NOT IDENTIFY SERVICE PORTS :

NEED SRV LOOKUP

QUERY MIGHT BE CACHED

AND NOT CORRECTLY LOADED

NO HEALTH CHECKING

DOES NOT HAVE FAST FAILOVER

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Alternative : lb-marathon for service discovery

cm-voting

cm-voting

lb-marathon

lb-marathon

Marathon

Mongolb-marathon

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Other Mesos frameworks

Singularity

Chronos

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Feedback from developer perspective

• Quite young tools : lots of changes in a short time

• Service discovery and load balancing troubleshooting

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Feedback from developer perspective

• Developer-oriented APIs

• Big community

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Future<MESOS>

• Multitenant workloads : not enough isolation -> app performance affected (multiple apps running in the same machine)

• Support for databases (Cassandra, HDFS, Kafka…) Until now mesos -> computed oriented tasks. Disk management.

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Thank you ! Questions ?

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