Some of the modern Operating Systems provide advanced Clustering capabilities themselves. Most of those Cluster features are designed to help porting "regular", non-clustered applications on these Cluster platforms. But some features provided with those Cluster OSes are very useful for the CommuniGate Pro Dynamic Cluster implementations.
These features include:
A Cluster File System allows all Servers in an OS Cluster to mount and use the same file system(s) on shared devices. Unlike Network File Systems (NFS), Cluster File Systems do not require a dedicated server on the network. Cluster File Systems can utilize multiple SCSI connections provided with some high-end SCSI storage devices, and they can allow each Server to exchange the data directly with storage devices via a SAN (Storage Area Network). To ensure file system integrity, Cluster File Systems use high-speed server interconnects.
The SAN protocols are very effective for file transfers, and Cluster File Systems can provide better performance than Network File Systems. The Cluster File Systems can also provide better reliability than single-server NFS solutions (where the NFS server is a single point of failure). See the Storage section for more details.
The IP Aliasing feature allows the Cluster OS to distribute the network load between Cluster Servers without an additional Load Balancer unit.
A "backend-only" CommuniGate Pro Dynamic Cluster can utilize both features of a Cluster OS: the IP Aliasing is used to distribute the load between CommuniGate Pro Server, and CommuniGate Pro Servers use the Cluster File System to store all account data in shared Domains:
A Cluster OS can be used in a frontend/backend CommuniGate Pro Cluster configuration, too. In this case, one OS Cluster is used for CommuniGate Pro frontend Servers, utilizing the IP Aliasing load balancing, and the second OS Cluster is used for CommuniGate Pro backend Servers, where the Cluster File System is employed:
The Configuration of the CommuniGate Pro Dynamic Cluster does not depend on the type of the load balancing used (separate Load Balancers or IP Aliases), or on the type of the shared file system used (Network File System or Cluster File System).