com.datastax.driver.core

Class Host

java.lang.Object

com.datastax.driver.core.Host

public class Host
extends Object

A Cassandra node. This class keeps the information the driver maintain on a given Cassandra node.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	Host.HealthMonitor Deprecated. See getMonitor().
static interface	Host.StateListener Interface for listeners that are interested in hosts added, up, down and removed events.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object o)
InetAddress	getAddress() Returns the node address.
String	getDatacenter() Returns the name of the datacenter this host is part of.
Host.HealthMonitor	getMonitor() Deprecated. you are encouraged not to use the HealthMonitor anymore. To test if a node is considered UP or not, you should use isUp instead. To register a Host.StateListener, you should do so at the Cluster level through Cluster.register(com.datastax.driver.core.Host.StateListener) (registering against the HealtMonitor does not work as intented: listeners will only be informed of onUp and onDown events (not onAdd and onRemove) and you need to manually register against every host. Cluster.register(com.datastax.driver.core.Host.StateListener) solves this).
String	getRack() Returns the name of the rack this host is part of.
int	hashCode()
boolean	isUp() Returns whether the host is considered up by the driver.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

getAddress

public InetAddress getAddress()

Returns the node address.

Returns:

the node InetAddress.

getDatacenter

public String getDatacenter()

Returns the name of the datacenter this host is part of. The returned datacenter name is the one as known by Cassandra. It is also possible for this information to be unavailable. In that case this method returns null, and the caller should always be aware of this possibility.

Returns:

the Cassandra datacenter name or null if datacenter is unavailable.

getRack

public String getRack()

Returns the name of the rack this host is part of. The returned rack name is the one as known by Cassandra. It is also possible for this information to be unavailable. In that case this method returns null, and the caller should always aware of this possibility.

Returns:

the Cassandra rack name or null if the rack is unavailable

isUp

public boolean isUp()

Returns whether the host is considered up by the driver.

Please note that this is only the view of the driver may not reflect the reality. In particular a node can be down but the driver hasn't detected it yet, or he can have been restarted but the driver hasn't detected it yet (in particular, for hosts to which the driver does not connect (because the LoadBalancingPolicy.distance method says so), this information may be durably inaccurate). This information should thus only be considered as best effort and should not be relied upon too strongly.

Returns:

whether the node is considered up.

getMonitor

@Deprecated
public Host.HealthMonitor getMonitor()

Deprecated. you are encouraged not to use the HealthMonitor anymore. To test if a node is considered UP or not, you should use isUp instead. To register a Host.StateListener, you should do so at the Cluster level through Cluster.register(com.datastax.driver.core.Host.StateListener) (registering against the HealtMonitor does not work as intented: listeners will only be informed of onUp and onDown events (not onAdd and onRemove) and you need to manually register against every host. Cluster.register(com.datastax.driver.core.Host.StateListener) solves this).

Returns the health monitor for this host. The health monitor keeps tracks of the known host state (up or down). A class implementing Host.StateListener can also register against the health monitor to be notified when this node is detected to be up or down

Returns:

the host Host.HealthMonitor.

hashCode

public final int hashCode()

Overrides:

hashCode in class Object

equals

public final boolean equals(Object o)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object