Galera Cluster vs Humongous.io: What are the differences?

# Introduction

1. **Scalability**:
   Galera Cluster is a synchronous multi-master cluster for MariaDB/MySQL, providing high availability and high scalability. On the other hand, Humongous.io is a storage solution for unstructured data that offers horizontal scalability by distributing data across multiple servers. The key difference in terms of scalability is that Galera Cluster is focused on databases while Humongous.io is designed for unstructured data storage.

2. **Data Structure**:
   Galera Cluster is centered around relational databases such as MariaDB/MySQL and ensures ACID compliance for transactions. In contrast, Humongous.io is specifically built for handling unstructured, document-oriented data using MongoDB. This difference in data structure highlights the diverse use cases catered to by each solution.

3. **Consistency Model**:
   Galera Cluster enforces strong consistency with synchronous replication among nodes to maintain data integrity. Meanwhile, Humongous.io follows eventual consistency, allowing for faster data retrieval by potentially sacrificing immediate consistency. This choice in consistency model influences the trade-offs between consistency, availability, and partition tolerance in the two systems.

4. **Deployment Complexity**:
   Galera Cluster requires database administrators to configure, manage, and monitor database clusters, ensuring data replication and failover mechanisms are correctly set up. In contrast, Humongous.io abstracts much of the complexity by offering a managed service for data storage, reducing the deployment overhead for users looking for a more hands-off solution.

5. **Data Handling**:
   Galera Cluster excels in handling relational database structures, supporting SQL queries and transactions typical in traditional database systems. Conversely, Humongous.io is tailored for managing and querying unstructured data in the form of JSON documents, allowing for more flexible and schema-less data storage and retrieval.

6. **Conflict Resolution**:
   In Galera Cluster, conflicts arising from concurrent writes are resolved using a certification-based approach to maintain data consistency across all nodes. However, Humongous.io leverages MongoDB's automatic conflict resolution mechanisms, such as last-write-wins or custom conflict resolution rules, to handle conflicts within the distributed document store.

In Summary, Galera Cluster and Humongous.io differ in scalability focus, data structure support, consistency models, deployment complexity, data handling capabilities, and conflict resolution mechanisms.