OrientDB can be deployed in a cluster architecture. It uses the Hazelcast open source project to manage the clustering. OrientDB currently supports the multi-master replication, in which each node of the cluster owns an exact replica of the database and can perform all kinds of operations against it. Of course, OrientDB manages the conflicts that could happen when more than one node wants to update the same information. Currently the clustering implementation is under heavy refactoring by the project team due to the implementation of the auto-sharing support.
Note
It is very important to know that replication works only for already created databases. Schema-related commands are not executed in a distributed environment. This means that you cannot create a new database in a node and see it in other nodes. Only data that is replicated across the cluster's nodes.