Package org.jgroups.blocks
Class PartitionedHashMap<K,V>
- java.lang.Object
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- org.jgroups.blocks.PartitionedHashMap<K,V>
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- 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:
- 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)
- Provide a better consistent hashing algorithm than ConsistentHashFunction as default
- GUI (showing at least the topology and L1 and L2 caches)
- Notifications (puts, removes, gets etc)
- Invalidation of L1 caches (if used) on removal/put of item
- Benchmarks, comparison to memcached
- Documentation, comparison to memcached
- Author:
- Bela Ban
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
PartitionedHashMap.ConsistentHashFunction<K>
static interface
PartitionedHashMap.HashFunction<K>
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Field Summary
Fields Modifier and Type Field Description protected static java.util.Map<java.lang.Short,java.lang.reflect.Method>
methods
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Constructor Summary
Constructors Constructor Description PartitionedHashMap(java.lang.String props, java.lang.String cluster_name)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Cache.Value<V>
_get(K key)
V
_put(K key, V val, long caching_time)
V
_remove(K key)
void
addMembershipListener(MembershipListener l)
void
block()
Called (usually by the FLUSH protocol), as an indication that the member should stop sending messages.java.lang.String
dump()
V
get(K key)
long
getCachingTime()
long
getCallTimeout()
java.lang.String
getClusterName()
PartitionedHashMap.HashFunction
getHashFunction()
Cache<K,V>
getL1Cache()
Cache<K,V>
getL2Cache()
Address
getLocalAddress()
java.lang.String
getLocalAddressAsString()
java.lang.String
getProps()
java.lang.String
getView()
boolean
isL1CacheEnabled()
boolean
isMigrateData()
void
put(K key, V val)
void
put(K key, V val, long caching_time)
Adds a key/value to the cache, replacing a previous item if there was onevoid
remove(K key)
void
removeMembershipListener(MembershipListener l)
void
setCachingTime(long caching_time)
void
setCallTimeout(long call_timeout)
void
setClusterName(java.lang.String cluster_name)
void
setHashFunction(PartitionedHashMap.HashFunction<K> hash_function)
void
setL1Cache(Cache<K,V> cache)
void
setL2Cache(Cache<K,V> cache)
void
setMigrateData(boolean migrate_data)
void
setProps(java.lang.String props)
void
start()
void
stop()
void
suspect(Address suspected_mbr)
Called whenever a member is suspected of having crashed, but has not yet been excluded.java.lang.String
toString()
void
unblock()
Called after the FLUSH protocol has unblocked previously blocked senders, and messages can be sent again.void
viewAccepted(View new_view)
Called when a change in membership has occurred.
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Method Detail
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getProps
public java.lang.String getProps()
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setProps
public void setProps(java.lang.String props)
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getLocalAddress
public Address getLocalAddress()
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getLocalAddressAsString
public java.lang.String getLocalAddressAsString()
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getView
public java.lang.String getView()
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isL1CacheEnabled
public boolean isL1CacheEnabled()
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getClusterName
public java.lang.String getClusterName()
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setClusterName
public void setClusterName(java.lang.String cluster_name)
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getCallTimeout
public long getCallTimeout()
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setCallTimeout
public void setCallTimeout(long call_timeout)
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getCachingTime
public long getCachingTime()
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setCachingTime
public void setCachingTime(long caching_time)
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isMigrateData
public boolean isMigrateData()
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setMigrateData
public void setMigrateData(boolean migrate_data)
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getHashFunction
public PartitionedHashMap.HashFunction getHashFunction()
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setHashFunction
public void setHashFunction(PartitionedHashMap.HashFunction<K> hash_function)
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addMembershipListener
public void addMembershipListener(MembershipListener l)
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removeMembershipListener
public void removeMembershipListener(MembershipListener l)
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start
public void start() throws java.lang.Exception
- Throws:
java.lang.Exception
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stop
public void stop()
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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 keyval
- The valuecaching_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
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remove
public void remove(K key)
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_get
public Cache.Value<V> _get(K key)
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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 whenJChannel.connect(String)
returns.- Specified by:
viewAccepted
in interfaceMembershipListener
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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 interfaceMembershipListener
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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, implementMembershipListener.unblock()
. Note that block() is the equivalent of reception of a BlockEvent in the pull mode.- Specified by:
block
in interfaceMembershipListener
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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 interfaceMembershipListener
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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
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dump
public java.lang.String dump()
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