Class PartitionedHashMap<K,​V>

  • All Implemented Interfaces:
    MembershipListener

    public class PartitionedHashMap<K,​V>
    extends java.lang.Object
    implements MembershipListener
    Hashmap which distributes its keys and values across the cluster. A PUT/GET/REMOVE computes the cluster node to which or from which to get/set the key/value from a hash of the key and then forwards the request to the remote cluster node. We also maintain a local cache (L1 cache) which is a bounded cache that caches retrieved keys/values.
    Todos:
    1. Use MarshalledValue to keep track of byte[] buffers, and be able to compute the exact size of the cache. This is good for maintaining a bounded cache (rather than using the number of entries)
    2. Provide a better consistent hashing algorithm than ConsistentHashFunction as default
    3. GUI (showing at least the topology and L1 and L2 caches)
    4. Notifications (puts, removes, gets etc)
    5. Invalidation of L1 caches (if used) on removal/put of item
    6. Benchmarks, comparison to memcached
    7. Documentation, comparison to memcached
    Author:
    Bela Ban
    • Field Detail

      • methods

        protected static final java.util.Map<java.lang.Short,​java.lang.reflect.Method> methods
    • Constructor Detail

      • PartitionedHashMap

        public PartitionedHashMap​(java.lang.String props,
                                  java.lang.String cluster_name)
    • Method Detail

      • getProps

        public java.lang.String getProps()
      • setProps

        public void setProps​(java.lang.String props)
      • getLocalAddress

        public Address getLocalAddress()
      • getLocalAddressAsString

        public java.lang.String getLocalAddressAsString()
      • getView

        public java.lang.String getView()
      • isL1CacheEnabled

        public boolean isL1CacheEnabled()
      • getClusterName

        public java.lang.String getClusterName()
      • setClusterName

        public void setClusterName​(java.lang.String cluster_name)
      • getCallTimeout

        public long getCallTimeout()
      • setCallTimeout

        public void setCallTimeout​(long call_timeout)
      • getCachingTime

        public long getCachingTime()
      • setCachingTime

        public void setCachingTime​(long caching_time)
      • isMigrateData

        public boolean isMigrateData()
      • setMigrateData

        public void setMigrateData​(boolean migrate_data)
      • removeMembershipListener

        public void removeMembershipListener​(MembershipListener l)
      • getL1Cache

        public Cache<K,​V> getL1Cache()
      • setL1Cache

        public void setL1Cache​(Cache<K,​V> cache)
      • getL2Cache

        public Cache<K,​V> getL2Cache()
      • setL2Cache

        public void setL2Cache​(Cache<K,​V> cache)
      • start

        public void start()
                   throws java.lang.Exception
        Throws:
        java.lang.Exception
      • stop

        public void stop()
      • put

        public void put​(K key,
                        V val)
      • put

        public void put​(K key,
                        V val,
                        long caching_time)
        Adds a key/value to the cache, replacing a previous item if there was one
        Parameters:
        key - The key
        val - The value
        caching_time - Time to live. -1 means never cache, 0 means cache forever. All other (positive) values are the number of milliseconds to cache the item
      • get

        public V get​(K key)
      • remove

        public void remove​(K key)
      • _put

        public V _put​(K key,
                      V val,
                      long caching_time)
      • _remove

        public V _remove​(K key)
      • viewAccepted

        public void viewAccepted​(View new_view)
        Description copied from interface: MembershipListener
        Called when a change in membership has occurred. No long running actions, sending of messages or anything that could block should be done in this callback. If some long running action needs to be performed, it should be done in a separate thread.

        Note that on reception of the first view (a new member just joined), the channel will not yet be in the connected state. This only happens when JChannel.connect(String) returns.

        Specified by:
        viewAccepted in interface MembershipListener
      • suspect

        public void suspect​(Address suspected_mbr)
        Description copied from interface: MembershipListener
        Called whenever a member is suspected of having crashed, but has not yet been excluded.
        Specified by:
        suspect in interface MembershipListener
      • block

        public void block()
        Description copied from interface: MembershipListener
        Called (usually by the FLUSH protocol), as an indication that the member should stop sending messages. Any messages sent after returning from this callback might get blocked by the FLUSH protocol. When the FLUSH protocol is done, and messages can be sent again, the FLUSH protocol will simply unblock all pending messages. If a callback for unblocking is desired, implement MembershipListener.unblock(). Note that block() is the equivalent of reception of a BlockEvent in the pull mode.
        Specified by:
        block in interface MembershipListener
      • unblock

        public void unblock()
        Description copied from interface: MembershipListener
        Called after the FLUSH protocol has unblocked previously blocked senders, and messages can be sent again. This callback only needs to be implemented if we require a notification of that.

        Note that during new view installation we provide guarantee that unblock invocation strictly follows view installation at some node A belonging to that view . However, some other message M may squeeze in between view and unblock callbacks. For more details see https://jira.jboss.org/jira/browse/JGRP-986

        Specified by:
        unblock in interface MembershipListener
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
      • dump

        public java.lang.String dump()