Package org.jgroups.blocks

Class PartitionedHashMap<K,V>

java.lang.Object
org.jgroups.blocks.PartitionedHashMap<K,V>
All Implemented Interfaces:
MembershipListener
public class PartitionedHashMap<K,V> extends 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 Details

  • Constructor Details

    • PartitionedHashMap

      public PartitionedHashMap(String props, String cluster_name)

  • Method Details

    • getProps

      public String getProps()

    • setProps

      public void setProps(String props)

    • getLocalAddress

      public Address getLocalAddress()

    • getLocalAddressAsString

      public String getLocalAddressAsString()

    • getView

      public String getView()

    • isL1CacheEnabled

      public boolean isL1CacheEnabled()

    • getClusterName

      public String getClusterName()

    • setClusterName

      public void setClusterName(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)

    • getHashFunction

      public PartitionedHashMap.HashFunction getHashFunction()

    • setHashFunction

      public void setHashFunction(PartitionedHashMap.HashFunction<K> hash_function)

    • addMembershipListener

      public void addMembershipListener(MembershipListener l)

    • 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 Exception
      Throws:
      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)

    • _get

      public Cache.Value<V> _get(K key)

    • _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 or sending of messages 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 Channel.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 ExtendedMembershipListener.unblock(). Note that block() is the equivalent of reception of a BlockEvent in the pull mode.
      Specified by:
      block in interface MembershipListener

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • dump

      public String dump()