ISPmanager Cluster is a software that enables to provide Shared-hosting to achieve new levels in rendering services.

Cluster is a group of homogeneous elements that act and consider as a single system.

All shared-hosting services are normally placed on one physical server. This approach has proven its stability, but has a number of drawbacks. For example, it does not provide high availability and scalability.  ISPmanager Cluster allows to solve this problem. 

Failover. Different kinds of services and tasks are distributed among several machines, and when one of them fails, it does not affect the whole system. In case of failure, everything you need is to change one server into another.

Scalability. As the number of your clients and/or load they create grows, you simply add new servers into the cluster.

Single entry point.  Unlike a  traditional approach "many servers - many control panels", ISPmanager Cluster has a single entry point to a control panel.  The ISPmanager Cluster web-server is based on ISPmanager Pro and has the same functionality for shared-hosting services. 

Operation scheme. Distribution of roles.

Below you can see the illustration of the ISPmanager Cluster operation scheme.  For more information about the cluster, please, read our Documentation.

Let's examine distribution of roles. The diagram below illustrates an ideal cluster system with all the roles distributed among different servers.  You do not need to have too many servers for testing.  You can start with several servers. Unfortunately, you will loss productivity and/or high availability, but you will be able to correctly create a shared hosting system.

ISPmanager Cluster can run only on one server.  It seems unreasonable in practice, but is quite appropriate for testing.