Horizontal Scalability and Multi-Server Mode

This section is dedicated to Workflow Server scalability and deployment.

• Workflow Server operates in the single-server mode by default, when it is highly recommended that a single Workflow Server instance is connected to a single database. Therefore, this mode is not suitable for horizontal scaling. The multi-server mode is the solution.
• In the multi-server mode, any number of Workflow Server instances can be connected to a single database. All these instances are independent, but they share a common database (or schema) in a cluster. The servers can be disconnected and connected to the database at any time; one server is enough to keep working the cluster.
• In case of failures or interruptions during the operation, the data of the active processes launched during the shutdown can be restored. The recovery procedure is used for that, and it can be customized. Even though one working server is enough to get everything back smoothly without customization. If the single server is implemented, just restart it to recover.
• Moreover, out-of-the-box Workflow Server supports multi-tenant applications.