com.github.ambry.clustermap

Class HelixClusterManager

java.lang.Object

com.github.ambry.clustermap.HelixClusterManager

All Implemented Interfaces:

com.github.ambry.clustermap.ClusterMap, java.lang.AutoCloseable

public class HelixClusterManager
extends java.lang.Object
implements com.github.ambry.clustermap.ClusterMap

An implementation of ClusterMap that makes use of Helix to dynamically manage the cluster information.

See Also:

http://helix.apache.org

Constructor Summary

Constructors

Constructor and Description
HelixClusterManager(com.github.ambry.config.ClusterMapConfig clusterMapConfig, java.lang.String instanceName, HelixFactory helixFactory, com.codahale.metrics.MetricRegistry metricRegistry) Instantiate a HelixClusterManager.

Method Summary

Modifier and Type	Method and Description
void	close() Disconnect from the HelixManagers associated with each and every datacenter.
java.util.List<com.github.ambry.clustermap.PartitionId>	getAllPartitionIds(java.lang.String partitionClass)
com.github.ambry.clustermap.ReplicaId	getBootstrapReplica(java.lang.String partitionIdStr, com.github.ambry.clustermap.DataNodeId dataNodeId) To create bootstrap replica, HelixClusterManager needs to fetch replica info (i.e.
java.lang.String	getDatacenterName(byte id)
com.github.ambry.clustermap.AmbryDataNode	getDataNodeId(java.lang.String hostname, int port)
java.util.List<com.github.ambry.clustermap.AmbryDataNode>	getDataNodeIds()
byte	getLocalDatacenterId()
com.codahale.metrics.MetricRegistry	getMetricRegistry()
com.github.ambry.clustermap.PartitionId	getPartitionIdFromStream(java.io.InputStream stream)
com.github.ambry.clustermap.PartitionId	getRandomWritablePartition(java.lang.String partitionClass, java.util.List<com.github.ambry.clustermap.PartitionId> partitionsToExclude)
java.util.List<com.github.ambry.clustermap.AmbryReplica>	getReplicaIds(com.github.ambry.clustermap.DataNodeId dataNodeId)
org.json.JSONObject	getSnapshot()
java.util.List<com.github.ambry.clustermap.PartitionId>	getWritablePartitionIds(java.lang.String partitionClass)
boolean	hasDatacenter(java.lang.String datacenterName)
void	onReplicaEvent(com.github.ambry.clustermap.ReplicaId replicaId, com.github.ambry.clustermap.ReplicaEventType event)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HelixClusterManager

public HelixClusterManager(com.github.ambry.config.ClusterMapConfig clusterMapConfig,
                           java.lang.String instanceName,
                           HelixFactory helixFactory,
                           com.codahale.metrics.MetricRegistry metricRegistry)
                    throws java.io.IOException

Instantiate a HelixClusterManager.

Parameters:

clusterMapConfig - the ClusterMapConfig associated with this manager.

instanceName - the String representation of the instance associated with this manager.

helixFactory - the factory class to construct and get a reference to a HelixManager.

metricRegistry - the registry of metric instances associated with this manager.

Throws:

java.io.IOException - if there is an error in parsing the clusterMapConfig or in connecting with the associated remote Zookeeper services.

Method Detail

hasDatacenter

public boolean hasDatacenter(java.lang.String datacenterName)

Specified by:

hasDatacenter in interface com.github.ambry.clustermap.ClusterMap

getLocalDatacenterId

public byte getLocalDatacenterId()

Specified by:

getLocalDatacenterId in interface com.github.ambry.clustermap.ClusterMap

getDatacenterName

public java.lang.String getDatacenterName(byte id)

Specified by:

getDatacenterName in interface com.github.ambry.clustermap.ClusterMap

getDataNodeId

public com.github.ambry.clustermap.AmbryDataNode getDataNodeId(java.lang.String hostname,
                                                               int port)

Specified by:

getDataNodeId in interface com.github.ambry.clustermap.ClusterMap

getReplicaIds

public java.util.List<com.github.ambry.clustermap.AmbryReplica> getReplicaIds(com.github.ambry.clustermap.DataNodeId dataNodeId)

Specified by:

getReplicaIds in interface com.github.ambry.clustermap.ClusterMap

getDataNodeIds

public java.util.List<com.github.ambry.clustermap.AmbryDataNode> getDataNodeIds()

Specified by:

getDataNodeIds in interface com.github.ambry.clustermap.ClusterMap

getMetricRegistry

public com.codahale.metrics.MetricRegistry getMetricRegistry()

Specified by:

getMetricRegistry in interface com.github.ambry.clustermap.ClusterMap

onReplicaEvent

public void onReplicaEvent(com.github.ambry.clustermap.ReplicaId replicaId,
                           com.github.ambry.clustermap.ReplicaEventType event)

Specified by:

onReplicaEvent in interface com.github.ambry.clustermap.ClusterMap

getSnapshot

public org.json.JSONObject getSnapshot()

Specified by:

getSnapshot in interface com.github.ambry.clustermap.ClusterMap

getPartitionIdFromStream

public com.github.ambry.clustermap.PartitionId getPartitionIdFromStream(java.io.InputStream stream)
                                                                 throws java.io.IOException

Specified by:

getPartitionIdFromStream in interface com.github.ambry.clustermap.ClusterMap

Throws:

java.io.IOException

getWritablePartitionIds

public java.util.List<com.github.ambry.clustermap.PartitionId> getWritablePartitionIds(java.lang.String partitionClass)

Specified by:

getWritablePartitionIds in interface com.github.ambry.clustermap.ClusterMap

getRandomWritablePartition

public com.github.ambry.clustermap.PartitionId getRandomWritablePartition(java.lang.String partitionClass,
                                                                          java.util.List<com.github.ambry.clustermap.PartitionId> partitionsToExclude)

Specified by:

getRandomWritablePartition in interface com.github.ambry.clustermap.ClusterMap

getAllPartitionIds

public java.util.List<com.github.ambry.clustermap.PartitionId> getAllPartitionIds(java.lang.String partitionClass)

Specified by:

getAllPartitionIds in interface com.github.ambry.clustermap.ClusterMap

getBootstrapReplica

public com.github.ambry.clustermap.ReplicaId getBootstrapReplica(java.lang.String partitionIdStr,
                                                                 com.github.ambry.clustermap.DataNodeId dataNodeId)

To create bootstrap replica, HelixClusterManager needs to fetch replica info (i.e. capacity, mount path) from Helix PropertyStore. This method looks up the ZNode in local datacenter and does some validation. Right now, HelixClusterManager supports getting bootstrap replica of new partition but it doesn't support getting replica residing on hosts that are not present in clustermap. The ZNRecord of REPLICA_ADDITION_ZNODE has following format in mapFields.

 "mapFields": {
     "1": {
         "replicaCapacityInBytes": 107374182400,
         "partitionClass": "max-replicas-all-datacenters",
         "localhost1_17088": "/tmp/c/1",
         "localhost2_17088": "/tmp/d/1"
     },
     "2": {
         "replicaCapacityInBytes": 107374182400,
         "partitionClass": "max-replicas-all-datacenters",
         "localhost3_17088": "/tmp/e/1"
     }
 }
 

In above example, two bootstrap replicas of partition[1] will be added to localhost1 and localhost2 respectively. The host name is followed by mount path on which the bootstrap replica should be placed.

Specified by:

getBootstrapReplica in interface com.github.ambry.clustermap.ClusterMap

close

public void close()

Disconnect from the HelixManagers associated with each and every datacenter.

Specified by:

close in interface com.github.ambry.clustermap.ClusterMap

Specified by:

close in interface java.lang.AutoCloseable