moqui-framework | Use Moqui Framework to build enterprise applications | REST library

Multi-tenant and the newer multi-instance variation on that are the opposite of what you're looking for. They are for large numbers of small instances, not a single large distributed instance with multiple application server instances running against the same database.

For clustering support by default Moqui uses Hazelcast, though that is done through a series of interfaces that can be implemented with other distributed computing tools. Here is the component needed to run a multi-server cluster with Hazelcast:

https://github.com/moqui/moqui-hazelcast

The most important aspects of clustering are cache invalidation for the entity (database) caches and web session replication. It also supports other tools for distributing workload and data as mentioned in the readme.

For distribution across multiple data centers or geographical regions there are much bigger issues. Moqui Framework is primarily for transactional applications like accounting, inventory management, etc that need strict transactional consistency. Big data or NoSQL style eventual consistency and other similar approaches do not do well with ERP and other transactional applications, there is no way to use locks and such in the database to protect against double spend of funds, double reservation or issuance of inventory, etc.

Consider the challenge of distributed relational transactional databases, ie multi-master database clusters. With multi-master setups a transaction must propagate to and commit on all master nodes before it can be considered committed. This has performance impacts even if all master nodes are on the same local network, and unreasonable performance impact if the master nodes are in different data centers or geographical regions.

The main solution to this is geographical sharding at the application level, usually mirroring the structure of a large business with geographic divisions. Moqui has some tool level support for this sort of thing using Entity Sync or other tools to feed data from geographic regions to a central server (or cluster) where reporting, etc can be done. There is no OOTB Entity Sync or other configuration for this sort of deployment, it's not something there has been demand for yet. This only makes sense for extremely large global corporations, not a market where Moqui has any use to my knowledge.

If you're looking at doing something like ecommerce and need the ecommerce sites distributed more widely the problem is easier than coordinating inventory or accounting across multiple global entities. For that just have separate ecommerce instances in different data centers feeding order/etc data to the Moqui ERP instance, very much like any typical external ecommerce application.