Galera Cluster vs H2 Database: What are the differences?

## Introduction
This Markdown code provides a comparison between Galera Cluster and H2 Database, highlighting key differences between the two.

1. **Scalability**: Galera Cluster is a synchronous multi-master database cluster solution, allowing for read and write operations across all nodes in real-time, providing high availability and horizontal scalability. In contrast, H2 Database is a lightweight, embedded database engine primarily suited for small to medium-sized applications, lacking the distributed capabilities of Galera Cluster.
   
2. **Consistency Model**: Galera Cluster uses the Certification Based Replication protocol to ensure strong consistency across all nodes, guaranteeing that transactions are committed in the same order on all nodes. On the other hand, H2 Database follows a traditional ACID (Atomicity, Consistency, Isolation, Durability) consistency model, providing strong consistency within a single instance but lacking the distributed consensus mechanism of Galera Cluster for multi-node deployments.
   
3. **Performance**: Galera Cluster is optimized for high-performance, supporting synchronous replication for real-time data access and failover capabilities. In contrast, H2 Database excels in low-latency, single-instance scenarios where high availability and distributed scalability are not primary concerns, making it ideal for lightweight applications with limited resources.
   
4. **Deployment Complexity**: Galera Cluster requires careful configuration and management to ensure proper setup of multi-node clusters, including considerations for network latency, quorum requirements, and data synchronization across all nodes. H2 Database, being a standalone embedded engine, offers simplicity in deployment with minimal setup requirements, making it suitable for rapid prototyping and small-scale projects.
   
5. **Community Support**: Galera Cluster is supported by a dedicated community of developers and contributors, providing regular updates, bug fixes, and new features to enhance the functionality and reliability of the cluster solution. In comparison, H2 Database has a smaller community base, resulting in less frequent updates and limited support resources for resolving issues or implementing advanced configurations.
   
6. **Storage Engine Compatibility**: Galera Cluster supports the use of various storage engines, such as InnoDB, TokuDB, and MyRocks, for data storage and management within the cluster environment. Conversely, H2 Database uses its embedded storage engine by default, limiting the flexibility in choosing alternative storage solutions based on specific performance or scalability requirements.

In Summary, Galera Cluster offers distributed multi-master capabilities with strong consistency, scalability, and performance optimizations, whereas H2 Database is more suitable for lightweight, single-instance deployments with simplicity in setup and low-latency operations.