co.cask.coopr.layout.change

Interface ClusterLayoutChange

All Known Implementing Classes:

AddServicesChange

public interface ClusterLayoutChange

Represents some change to a ClusterLayout, such as adding a service to some of the nodes. Caller is responsible for calling the canApplyChange(co.cask.coopr.layout.ClusterLayout) method to validate if a change can be applied to a layout before actually applying the change with applyChange(co.cask.coopr.layout.ClusterLayout) or applyChange(co.cask.coopr.cluster.Cluster, java.util.Set, java.util.Map).

Method Summary

Methods

Modifier and Type	Method and Description
ClusterLayout	applyChange(ClusterLayout layout) Apply the change to the given ClusterLayout.
Set<Node>	applyChange(Cluster cluster, Set<Node> clusterNodes, Map<String,Service> serviceMap) Apply the change to a set of nodes, returning nodes that have changed.
boolean	canApplyChange(ClusterLayout layout) Returns whether or not the change can be applied to the given ClusterLayout.

Method Detail

canApplyChange

boolean canApplyChange(ClusterLayout layout)

Returns whether or not the change can be applied to the given ClusterLayout. This is not for checking if the resulting cluster layout would satisfy all its constraints, but for checking whether or not it is physically possible to apply the change. For example, it is not physically possible to add a service to 10 nodes if the cluster is only 5 nodes.

Parameters:

layout - Layout to check the legality of the change for.

Returns:

True if the change can be applied, false if not.

applyChange

ClusterLayout applyChange(ClusterLayout layout)

Apply the change to the given ClusterLayout. Returns a new layout object and does not modify the given layout.

Parameters:

layout - Layout to apply the change to.

Returns:

New layout object after the change.

applyChange

Set<Node> applyChange(Cluster cluster,
                    Set<Node> clusterNodes,
                    Map<String,Service> serviceMap)

Apply the change to a set of nodes, returning nodes that have changed.

Parameters:

cluster - Cluster to apply the change to.

clusterNodes - Nodes to apply the change to.

serviceMap - Map of service name to Service for available services. TODO: remove the need for the serviceMap