Get started with Developing Frameworks in Go on Apache Mesos

Joe Stein

CEO, Co-Founder of Elodina Inc, Software Platform focused on simplified operations of data oriented systems by providing the tools and support necessary to fully utilize their data center resources.

LinkedIn: http://linkedin.com/in/charmalloc Twitter : @allthingshadoop

◉ What is Mesos?◉ Framework = (Scheduler + Executor)◉ Framework API Examples◉ More Mesos!

Overview

What is Mesos?

Origins

◉ A Common Substrate for Cluster Computing https://people.csail.mit.edu/matei/papers/2009/hotcloud_nexus.pdf

◉ Mesos: A Platform for Fine-Grained Resource Sharing in the Data Center http://static.usenix.org/event/nsdi11/tech/full_papers/Hindman_new.pdf

◉ Google Borg - https://research.google.com/pubs/pub43438.html◉ Google Omega: flexible, scalable schedulers for large compute clusters http:

//eurosys2013.tudos.org/wp-content/uploads/2013/paper/Schwarzkopf.pdf

static vs elastic

Data Center Kernel

Data Center Operating System

Mesosphere’s Data Center Operating System (DCOS) is an operating system that spans all of the machines in a datacenter or cloud and treats them as a single computer, providing a highly elastic and highly scalable way of deploying applications, services, and big data infrastructure on shared resources. DCOS is based on Apache Mesos and includes a distributed systems kernel with enterprise-grade security. It also includes a set of core system services, such as a native Marathon instance to manage processes and installable services, and Mesos-DNS for service discovery. DCOS provides a web interface and a command-line interface (CLI) to manage the deployment and scale of applications.

Framework = (Scheduler + Executor)

Scheduler

Executors

Marathonhttps://github.com/mesosphere/marathonCluster-wide init and control system for services in cgroups or docker based on Apache Mesos

Stack Deploy https://github.com/elodina/stack-deploy

Use YAML to Configure Your Deploy

Framework API & Examples

Mesos Protos

https://github.com/apache/mesos/blob/master/include/mesos/mesos.proto

Everything is good to understand but here is a good place to start

◉ FrameworkInfo◉ TaskInfo◉ TaskState◉ MasterInfo◉ SlaveInfo

Mesos Framework Development Guide

http://mesos.apache.org/documentation/latest/app-framework-development-guide/

Go Bindings https://github.com/mesos/mesos-go

◉ Scheduler API○ registered, reregistered, disconnected○ resourceOffers, offerRescinded, statusUpdate, frameworkMessage○ slaveLost, executorLost, error

◉ Executor API○ registered, reregistered, disconnected○ launchTask, killTask, frameworkMessage

Go Kafka Client Mesos https://github.com/elodina/go-kafka-client-mesos

More About the Scheduler

Scheduler

Scheduler

Scheduler

Task Reconciliation

http://mesos.apache.org/documentation/latest/reconciliation/

It is the responsibility of Mesos (scheduler driver / Master) to ensure that the framework is notified when a disconnection, and subsequent (re-)registration occurs. At this point, the scheduler should perform task state reconciliation.

Executor

Executor

More Schedulers to Check out

◉ https://github.com/elodina/statsd-mesos-kafka◉ https://github.com/elodina/syslog-service◉ https://github.com/mesos/kafka◉ https://github.com/elodina/exhibitor-mesos-framework ◉ https://github.com/elodina/go-kafka-client-mesos◉ https://github.com/elodina/datastax-enterprise-mesos◉ https://github.com/elodina/zipkin-mesos-framework

More Mesos!

The Mesos system has two basic methods to describe the slaves that comprise a cluster. One of these is managed by the Mesos master, the other is simply passed onwards to the frameworks using the cluster.

AttributesThe attributes are simply key value string pairs that Mesos passes along when it sends offers to frameworks.

Resources & Attributes

ResourcesThe Mesos system can manage 3 different types of resources: scalars, ranges, and sets. These are used to represent the

different resources that a Mesos slave has to offer. For example, a scalar resource type could be used to represent the

amount of memory on a slave. Each resource is identified by a key string.

Predefined Uses & Conventions

The Mesos master has a few resources that it pre-defines in how it handles them. At the current time, this list consist of:

●●●●

In particular, a slave without and resources will never have its resources advertised to any frameworks. Also, the Master’s

user interface interprets the scalars in and in terms of . IE: the value is displayed as .

ExamplesHere are some examples for configuring the Mesos slaves.

In this case, we have three different types of resources, scalars, a range, and a set. They are called , , , and the range type

is .

● scalar called , with the value

● scalar called , with the value

● scalar called , with the value

● range called , with values through (inclusive)

● set called , with the values , and

In the case of attributes, we end up with three attributes:

● with value

● with value

● with value

RolesTotal consumable resources per slave, in the form 'name(role):value;name(role):value...'. This value can be set to limit resources per role, or to overstate the number of resources that are available to the slave.

All * roles will be detected, so you can specify only the resources that are not all roles (*).

ConstraintsConstraints control where apps run to allow optimizing for fault tolerance or locality. Constraints are made up of three parts: a field

name, an operator, and an optional parameter. The field can be the slave hostname or any Mesos slave attribute.

Fields

Hostname field

field matches the slave hostnames, see for usage example.

field supports all operators of Marathon.

Attribute field

If the field name is none of the above, it will be treated as a Mesos slave attribute. Mesos slave attribute is a way to tag a slave node,

see to learn how to set the attributes.

Unique tells Marathon to enforce uniqueness of the attribute across all of an app's tasks. For example the following constraint ensures

that there is only one app task running on each host:

via the Marathon gem:

via curl:

allows you to run all of your app's tasks on slaves that share a certain attribute.

You can also use this attribute to tie an application to a specific node by using the hostname property:

Cluster

Group By can be used to distribute tasks evenly across racks or datacenters for high availability.

via the Marathon gem:

via curl:

Optionally, you can specify a minimum number of groups to try and achieve.

Like accepts a regular expression as parameter, and allows you to run your tasks only on the slaves whose field values match the

regular expression.

via the Marathon gem:

via curl:

UnlikeJust like operator, but only run tasks on slaves whose field values don't match the regular expression.

via the Marathon gem:

via curl:

Go Mesos Constraints & More!

https://github.com/elodina/go-mesos-utils

--constraints: Constraints (hostname=like:^master$,rack=like:^1.*$).

Questions?

Joe Steinhttp://www.elodina.net