com.bigdata.ganglia

Interface IGangliaState

All Known Implementing Classes:

GangliaState

public interface IGangliaState

A read-only view of the soft state of the cluster as maintained through the ganglia protocol.

Version:

$Id$

Author:

Bryan Thompson

Method Summary

Methods

Modifier and Type	Method and Description
String	getHostName() Return the name of this host.
String[]	getKnownHosts() Return a snapshot of the known hosts.
IGangliaMetadataMessage	getMetadata(String metricName) Return the metadata for the given metric.
ITimestampMetricValue	getMetric(String hostName, String metricName) Return current TimestampMetricValue of metric on host (thread-safe).
Iterator<? extends ITimestampMetricValue>	iterator(String hostName) Return an iterator which will visit all timestamped metrics for the specified host.

Method Detail

getHostName

String getHostName()

Return the name of this host.

getKnownHosts

String[] getKnownHosts()

Return a snapshot of the known hosts.

Returns:

The names of the known hosts and never null.

iterator

Iterator<? extends ITimestampMetricValue> iterator(String hostName)

Return an iterator which will visit all timestamped metrics for the specified host.

Parameters:

hostName - The host name.

Returns:

The iterator and never null.

getMetadata

IGangliaMetadataMessage getMetadata(String metricName)

Return the metadata for the given metric.

Parameters:

metricName - The metric name (as it appears in ganglia messages).

Returns:

The metadata for that metric iff it is a known metric and otherwise null.

getMetric

ITimestampMetricValue getMetric(String hostName,
                              String metricName)

Return current TimestampMetricValue of metric on host (thread-safe).

If an IGangliaMetadataMessage is declared for that name, then either the pre-existing TimestampMetricValue will be returned -or- a new TimestampMetricValue will be atomically created and returned.

Otherwise, this method will return null since it lacks the necessary information to create an IGangliaMetadataMessage by itself.

Parameters:

hostName - The name of the host.

metricName - The name of the metric.

Returns:

The current value of the metric on that host -or- null if there is no IGangliaMetadataMessage for that metric.