Marathon or Mesos: Running Distributed Systems Like a Pro
Published: 2023-10-06 18:12:14

## Introduction

As the world becomes increasingly interconnected, the ability to efficiently manage and execute complex distributions systems has become more critical than ever. Operating at such a large scale whilst ensuring performance, durability, and synchronization is no small challenge. Fortunately, with the advent of technologies such as Marathon and Mesos, managing large-scale distributed systems has become significantly more manageable.

Considered as a pivotal aspect of the DevOps culture, these sophisticated technologies have streamlined the process of deployment, scaling, and management of containerized applications across clusters. With their sophisticated set of features and functionalities, Marathon and Mesos – both are Apache projects – have turned out to be reliable tools for DevOps specialists and system engineers dealing with distributed systems.

>"Simplicity is the soul of efficiency" - Austin Freeman

This is how both Mesos and Marathon operate. With Mesos viewing your cluster as a single pool of resources, and Marathon using these resources to execute & maintain apps in a fault-tolerant manner, they each strive to simplify the otherwise complex nature of managing distributed systems.

As Bill Clinton once said, "The price of doing the same old thing is far higher than the price of change." In that spirit, let's explore Marathon and Mesos in more depth, highlighting their unique features, capabilities, comparative advantages and some real-time code snippets to help you make an informed decision.

## Marathon: The Marathon Runner of Distributed Systems

Marathon is a private Platform as a Service (PaaS) backed by Mesos, designed to launch long-running applications. Let's boil down into its essence.

```bash
# Installing Marathon
sudo apt-get install marathon
```

Upon installation, ranging from a simple HTTP server to a sophisticated database cluster, you can launch anything that can be launched in a traditional shell. It provides users with a wealth of features including app health checks,  high availability of applications, event subscriptions, event subscriptions, constraints, and service discovery.

```json
# Basic App definition 
{
   "id": "basic-service",
   "cmd": "while [ true ] ; do nc -lp $PORT0; done",
   "cpus": 0.1,
   "mem": 10.0,
   "instances": 2
}
```

The above code launches a network service that listens to the port provided by the `$PORT0` environment variable.

## Mesos: A Scalable Open-Source Program for Optimized Resource Sharing

Mesos is essentially a distributed systems kernel. It provides the primitives upon which Marathon, among other frameworks, are built. Mesos takes care of resource sharing amongst various applications and services in an efficient, scalable, and reliable manner.

Installation is fairly simplified:

```bash
# Installing Mesos
sudo apt-get install mesos
```

Mesos allows an application to abstract CPU, memory, storage, and more from machines, whether they are physical or virtual, on-premises, or in the cloud. Through fine-grained resource allocation, it ensures maximum use of cluster resources. 

Its two-level scheduling mechanism doesn't make scheduling decisions itself, instead it only provides offers representing available resources, and frameworks (like Marathon) decide which resources to use.

## Marathon vs. Mesos: a Comparative Overview

Now that we have introduced each player, it is time to compare them on multiple axes. 

| Functionality | Mesos | Marathon | 
| --- | --- | --- | 
| **Stateless Services** | Yes | Yes | 
| **Stateful Services** | No | Yes | 
| **Multi-Tenancy** | Yes | Yes |
| **Rolling Upgrades**| No |  Yes |
| **Service Discovery** | No | Yes |
| **Load Balancing** | Requires external service | Requires external service |

Most features are the same in both cases; Marathon & Mesos are inherently designed to handle large-scale distributed systems. However, the distinctions are in the details.

>_Steve Wozniak once said, "I think there is a world market for maybe five computers."_ If only he knew how times would change. Today, successful management of distributed systems is a growing demand in technology.

## Conclusion

In simple terms, Mesos is best suited if your workloads are based on assorted microservices running in containers while Marathon is more applicable if your concern is to ensure high availability of long-running applications.

Both Mesos & Marathon are powerful & versatile tools designed with the mindset of ‘making operations easy’. They emerge from different corners of the problem space, but together, they work seamlessly, providing solutions for cluster management, workload scheduling, and maintaining the desired state—all key to running distributed systems like a pro!

At the end of the day, choosing between Marathon and Mesos isn't an "either-or" decision. True distributed system management nirvana lies in mastering both. It's more akin to choosing between Stallone & Schwarzenegger in their prime; both superstars, yet each with their unique style and flair.

What makes these tools exotic, cutting-edge and ultimately, the choice of pro-users, is their combined ability to manage resources adeptly and efficiently. Remember, being a pro at managing distributed systems isn't just about using the right tools, it’s about understanding their strengths, limitations, and leveraging them strategically.

+"As Alan Kay said, "Simple things should be simple, complex things should be possible." With Mesos and Marathon, achieving that possibility is within reach!