module cluster-admin {
    yang-version 1;
    namespace "urn:opendaylight:params:xml:ns:yang:controller:md:sal:cluster:admin";
    prefix "cluster-admin";

    description
        "This module contains YANG RPC definitions for administering a cluster.";

    revision "2015-10-13" {
        description "Initial revision.";
    }

    typedef data-store-type {
        type enumeration {
            enum config {
                value 1;
            }
            enum operational {
                value 2;
            }
        }
    }

    grouping shard-operation-result {
        leaf shard-name {
            type string;
        }

        leaf data-store-type {
            type data-store-type;
        }

        leaf succeeded {
            type boolean;
        }

        leaf error-message {
            type string;
        }
    }

    grouping shard-result-output {
        list shard-result {
            key "shard-name data-store-type";
            uses shard-operation-result;

            description "The list of results, one per shard";
        }
    }
    
    rpc add-shard-replica {
        input {
            leaf shard-name {
                mandatory true;
                type string;
                description "The name of the shard for which to create a replica.";
            }

            leaf data-store-type {
                mandatory true;
                type data-store-type;
                description "The type of the data store to which the replica belongs";
            }
        }

        description "Adds a replica of a shard to this node and joins it to an existing cluster. The shard must
            already have a module configuration defined for it and there must already be a shard existing on
            another node with a leader. This RPC first contacts peer member seed nodes searching for a shard.
            When found, an AddServer message is sent to the shard leader and applied as described in the Raft
            paper.";
    }

    rpc remove-shard-replica {
        input {
            leaf shard-name {
                mandatory true;
                type string;
                description "The name of the shard for which to remove the replica.";
            }

            leaf member-name {
                mandatory true;
                type string;
                description "The cluster member from which the shard replica should be removed";
            }

            leaf data-store-type {
                mandatory true;
                type data-store-type;
                description "The type of the data store to which the replica belongs";
            }
        }

        description "Removes an existing replica of a shard from this node via the RemoveServer mechanism as
            described in the Raft paper.";
    }

    rpc add-replicas-for-all-shards {
        output {
            uses shard-result-output;
        }

        description "Adds replicas on this node for all currently defined shards. This is equivalent to issuing
            an add-shard-replica RPC for all shards.";
    }

    rpc remove-all-shard-replicas {
        input {
            leaf member-name {
                mandatory true;
                type string;
                description "The cluster member from which the shard replicas should be removed";
            }
        }
        
        output {
            uses shard-result-output;
        }
        
        description "Removes replicas for all shards on this node. This is equivalent to issuing
            a remove-shard-replica for all shards and essentially removes this node from a cluster.";
    }

    rpc convert-members-to-nonvoting-for-all-shards {
        input {
            leaf-list member-names {
                type string;
                description "The names of the cluster members to convert.";
            }
        }
        
        description "Converts the given cluster members to non-voting for all shards. The members will no 
            longer participate in leader elections and consensus but will be replicated. This is useful for
            having a set of members serve as a backup cluster in case the primary voting cluster suffers
            catastrophic failure. This RPC can be issued to any cluster member and will be forwarded
            to the leader.";
    }

    rpc convert-members-to-voting-for-all-shards {
        input {
            leaf-list member-names {
                type string;
                description "The names of the cluster members to convert.";
            }
        }

        description "Converts the given cluster members to voting for all shards. The members will 
            participate in leader elections and consensus.";
    }

    rpc backup-datastore {
        input {
            leaf file-path {
              type string;
              description "The path and name of the file in which to store the backup.";
            }
        }

        description "Creates a backup file of the datastore state";
    }
}