Package org.apache.bookkeeper.net

Class NetworkTopologyImpl

  • All Implemented Interfaces:
    NetworkTopology
    public class NetworkTopologyImpl
extends java.lang.Object
implements NetworkTopology
    The class represents a cluster of computer with a tree hierarchical network topology. For example, a cluster may be consists of many data centers filled with racks of computers. In a network topology, leaves represent data nodes (computers) and inner nodes represent switches/routers that manage traffic in/out of data centers or racks.

    • Field Detail

      • LOG

        public static final org.slf4j.Logger LOG

      • numOfRacks

        protected int numOfRacks
        Rack counter.

      • netlock

        protected java.util.concurrent.locks.ReadWriteLock netlock
        The lock used to manage access.

    • Constructor Detail

      • NetworkTopologyImpl

        public NetworkTopologyImpl()

    • Method Detail

      • add

        public void add​(Node node)
        Add a leaf node. Update node counter and rack counter if necessary
        Specified by:
        add in interface NetworkTopology
        Parameters:
        node - node to be added; can be null
        Throws:
        java.lang.IllegalArgumentException - if add a node to a leave or node to be added is not a leaf

      • getNodeForNetworkLocation

        protected Node getNodeForNetworkLocation​(Node node)
        Return a reference to the node given its string representation. Default implementation delegates to getNode(String).

        To be overridden in subclasses for specific NetworkTopology implementations, as alternative to overriding the full add(Node) method.

        Parameters:
        node - The string representation of this node's network location is used to retrieve a Node object.
        Returns:
        a reference to the node; null if the node is not in the tree
        See Also:
        add(Node), getNode(String)

      • getDatanodesInRack

        public java.util.List<Node> getDatanodesInRack​(java.lang.String loc)
        Given a string representation of a rack, return its children.
        Parameters:
        loc - a path-like string representation of a rack
        Returns:
        a newly allocated list with all the node's children

      • remove

        public void remove​(Node node)
        Remove a node. Update node counter and rack counter if necessary.
        Specified by:
        remove in interface NetworkTopology
        Parameters:
        node - node to be removed; can be null

      • contains

        public boolean contains​(Node node)
        Check if the tree contains node node.
        Specified by:
        contains in interface NetworkTopology
        Parameters:
        node - a node
        Returns:
        true if node is already in the tree; false otherwise

      • getNode

        public Node getNode​(java.lang.String loc)
        Given a string representation of a node, return its reference.
        Specified by:
        getNode in interface NetworkTopology
        Parameters:
        loc - a path-like string representation of a node
        Returns:
        a reference to the node; null if the node is not in the tree

      • getRack

        public java.lang.String getRack​(java.lang.String loc)
        Given a string representation of a rack for a specific network location.

        To be overridden in subclasses for specific NetworkTopology implementations, as alternative to overriding the full getRack(String) method.

        Parameters:
        loc - a path-like string representation of a network location
        Returns:
        a rack string

      • getNumOfRacks

        public int getNumOfRacks()
        Description copied from interface: NetworkTopology
        Returns number of racks in the network topology.
        Specified by:
        getNumOfRacks in interface NetworkTopology
        Returns:
        the total number of racks

      • getNumOfLeaves

        public int getNumOfLeaves()
        Returns:
        the total number of leaf nodes

      • getDistance

        public int getDistance​(Node node1,
                       Node node2)
        Return the distance between two nodes.

        It is assumed that the distance from one node to its parent is 1 The distance between two nodes is calculated by summing up their distances to their closest common ancestor.

        Parameters:
        node1 - one node
        node2 - another node
        Returns:
        the distance between node1 and node2 which is zero if they are the same or Integer.MAX_VALUE if node1 or node2 do not belong to the cluster

      • isOnSameRack

        public boolean isOnSameRack​(Node node1,
                            Node node2)
        Check if two nodes are on the same rack.
        Parameters:
        node1 - one node (can be null)
        node2 - another node (can be null)
        Returns:
        true if node1 and node2 are on the same rack; false otherwise
        Throws:
        java.lang.IllegalArgumentException - when either node1 or node2 is null, or node1 or node2 do not belong to the cluster

      • isNodeGroupAware

        public boolean isNodeGroupAware()
        Check if network topology is aware of NodeGroup.

      • isOnSameNodeGroup

        public boolean isOnSameNodeGroup​(Node node1,
                                 Node node2)
        Return false directly as not aware of NodeGroup, to be override in sub-class.

      • isSameParents

        protected boolean isSameParents​(Node node1,
                                Node node2)
        Compare the parents of each node for equality.

        To be overridden in subclasses for specific NetworkTopology implementations, as alternative to overriding the full isOnSameRack(Node, Node) method.

        Parameters:
        node1 - the first node to compare
        node2 - the second node to compare
        Returns:
        true if their parents are equal, false otherwise
        See Also:
        isOnSameRack(Node, Node)

      • chooseRandom

        public Node chooseRandom​(java.lang.String scope)
        Randomly choose one node from scope.

        If scope starts with ~, choose one from the all nodes except for the ones in scope; otherwise, choose one from scope.

        Parameters:
        scope - range of nodes from which a node will be chosen
        Returns:
        the chosen node

      • getLeaves

        public java.util.Set<Node> getLeaves​(java.lang.String scope)
        Description copied from interface: NetworkTopology
        Returns the nodes under a location.
        Specified by:
        getLeaves in interface NetworkTopology
        Parameters:
        scope - network location
        Returns:
        nodes under a location

      • countNumOfAvailableNodes

        public int countNumOfAvailableNodes​(java.lang.String scope,
                                    java.util.Collection<Node> excludedNodes)
        Description copied from interface: NetworkTopology
        Return the number of leaves in scope but not in excludedNodes.

        If scope starts with ~, return the number of nodes that are not in scope and excludedNodes;

        Specified by:
        countNumOfAvailableNodes in interface NetworkTopology
        Parameters:
        scope - a path string that may start with ~
        excludedNodes - a list of nodes
        Returns:
        number of available nodes

      • toString

        public java.lang.String toString()
        Convert a network tree to a string.
        Overrides:
        toString in class java.lang.Object

      • getFirstHalf

        public static java.lang.String getFirstHalf​(java.lang.String networkLocation)
        Divide networklocation string into two parts by last separator, and get the first part here.
        Parameters:
        networkLocation -
        Returns:

      • getLastHalf

        public static java.lang.String getLastHalf​(java.lang.String networkLocation)
        Divide networklocation string into two parts by last separator, and get the second part here.
        Parameters:
        networkLocation -
        Returns:

      • swap

        protected static void swap​(Node[] nodes,
                           int i,
                           int j)
        Swap two array items.

      • pseudoSortByDistance

        public void pseudoSortByDistance​(Node reader,
                                 Node[] nodes)
        Sort nodes array by their distances to reader It linearly scans the array, if a local node is found, swap it with the first element of the array. If a local rack node is found, swap it with the first element following the local node. If neither local node or local rack node is found, put a random replica location at position 0. It leaves the rest nodes untouched.
        Parameters:
        reader - the node that wishes to read a block from one of the nodes
        nodes - the list of nodes containing data for the reader