Shared and Replication of Databases

FioranoMQ provides complete flexibility to administrators giving them an option of either using a shared database (between active and passive servers) or using database replication (from active to passive server). "Shared" HA typically provides much better performance in comparison with "Replicated" HA. If it is not possible to share a database, administrators can still use FioranoMQ's HA using inbuilt replication support.

Application Failover

If the primary server becomes unavailable, all the client applications connected to it are automatically re-connected to the secondary server. The process of shifting from the primary server to the backup server or vice-versa is transparent to the application. The application does not need to implement any reconnect logic in its code. Re-connection achieved by connecting to the server through a Durable Connection. If a backup server is available, the Durable Connection will connect to the backup server. Otherwise it waits for the server to restart and during the disconnected period stores all data in to a local repository. This data is re-transferred to the server as soon as a connection is re-established, making the system highly reliable and robust even in the event of network failures.
Note: Durable connections implement 'client side persistence' and are a proprietary feature of FioranoMQ (though it does not require any proprietary APIs) and should not be confused with Durable Subscribers.

Data Store Consistency (maintained between server switches)

When the primary server becomes unavailable, its backend database state is preserved. This state is picked up by the secondary server when it becomes available. This avoids loss of persistent information between server switches while, at the same time, providing access to information stored to the backup server. For example, all the messages published on various destinations residing on the primary server are available to valid consumers through the secondary backup server without loss.

Expensive HA Hardware Not Required

Fiorano's HA solution is implemented using software and is not dependent on expensive hardware solutions. It can run on any java-supported platform. With the shared database option, one might want to use RAID or SAN disks (if using HA over Fiorano's proprietary file-based data store) for enhanced speed and stability, but this hardware is not necessary for Fiorano's HA solution. Using either replication support or using a central RDBMS server as the message store in the Enterprise Server avoids the need for additional hardware.

Implementing a Cluster

The Enterprise Server can be clustered with other Enterprise Servers or even stand-alone FioranoMQ servers. The cluster can share destinations (using a common naming store) and provide load-balancing facilities.