Vcluster(virtual cluster) is the basic concept in Docklet. A vcluster consists of at least one LXC container nodes, each node can be regarded as a lightweight Linux host. Usually, the container nodes of one vcluster are generated from the same image, which can simplify the management of vcluster.
The level of the user determines the quota of his vcluster, including the maximum number of nodes the vcluster can have, the CPU and memory config of each container node, etc. The default vcluster has one node.
The nodes of Docklet vcluster are designed to distribute to different physical hosts as most as possible, in order to better utilize physical resources. Those distributed nodes can communicate with each other. One docklet vcluster will use an independent virtual sub-network, usually the first node is the gateway of this sub-network.
In most cases, users do not need to care about the details of vcluster, but only need to focus on their Workspace.
In some special cases, users may need to configure the vcluster to meet the requirements of upper Workspace. For example, in order to run program parallelly in Workspace, users need to scale out the default vcluster, adding more nodes. Docklet vcluster has the ability of elastic scaling, supporting adding or removing nodes at any time.