com.bigdata.ganglia

Class GangliaMetadataMessage

java.lang.Object

com.bigdata.ganglia.AbstractGangliaMessage

com.bigdata.ganglia.GangliaMetadataMessage

All Implemented Interfaces:

IGangliaMessage, IGangliaMetadataMessage

public class GangliaMetadataMessage
extends AbstractGangliaMessage
implements IGangliaMetadataMessage

A ganglia metric metadata (aka declaration) record.

This record must be sent if a service is reporting a metric for the first time. In addition, ganglia resends the metadata records periodically by tracking their age (but send_metadata_interval = 0 in the default gmond.conf).

Constructor Summary

Constructors

Constructor and Description
GangliaMetadataMessage(String hostName, String metricName, boolean spoof, GangliaMessageTypeEnum metricType, String metricName2, String units, GangliaSlopeEnum slope, int tmax, int dmax, Map<String,String[]> extraValues)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object o)
String	getDescription() Return the value of the well-known attribute IGangliaAttributes.ATTR_DESC.
int	getDMax() The maximum age in seconds before a metric will be deleted (aka Delete Max).
Map<String,String[]>	getExtraValues() Zero or more additional name-value[] pairs serialized with this message.
String	getFirstValue(String key) Return the first value for the given key from the IGangliaMetadataMessage.getExtraValues().
String[]	getGroups() Return the value of the well-known attribute IGangliaAttributes.ATTR_TITLE.
String	getMetricName2() The metric name (this is represented twice in the Ganglia 3.1 wire format: once in the metric_id header and once in the metadata record; both values SHOULD be the same).
GangliaMessageTypeEnum	getMetricType() The data type declaration for the metric.
GangliaSlopeEnum	getSlope() Hint for rrdtool visualization of metric values.
String	getTitle() Return the value of the well-known attribute IGangliaAttributes.ATTR_TITLE.
int	getTMax() The maximum advisory delay in seconds before a metric value would become stale.
String	getUnits() The units in which the metric values are expressed.
int	hashCode()
boolean	isChanged(Object oldValue, Object newValue) Return true iff the newValue differs significantly from the old value.
boolean	isMetricMetadata() Return true iff this message contains the metadata for a metric (the metric declaration).
boolean	isMetricRequest() Return true iff this message is a request for a metric.
boolean	isMetricValue() Return true if this message represents a metric value.
String	toString()
Object	translateValue(Object value) Return a value which may have been scaled and/or offset in order to align the value with the metric declaration.

Methods inherited from class com.bigdata.ganglia.AbstractGangliaMessage

getHostName, getMetricName, getRecordType, isSpoof

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.bigdata.ganglia.IGangliaMessage

getHostName, getMetricName, getRecordType, isSpoof

Constructor Detail

GangliaMetadataMessage

public GangliaMetadataMessage(String hostName,
                      String metricName,
                      boolean spoof,
                      GangliaMessageTypeEnum metricType,
                      String metricName2,
                      String units,
                      GangliaSlopeEnum slope,
                      int tmax,
                      int dmax,
                      Map<String,String[]> extraValues)

Method Detail

isMetricValue

public boolean isMetricValue()

Description copied from interface: IGangliaMessage

Return true if this message represents a metric value.

Specified by:

isMetricValue in interface IGangliaMessage

isMetricRequest

public boolean isMetricRequest()

Description copied from interface: IGangliaMessage

Return true iff this message is a request for a metric.

Specified by:

isMetricRequest in interface IGangliaMessage

See Also:

GangliaMessageTypeEnum.REQUEST

isMetricMetadata

public boolean isMetricMetadata()

Description copied from interface: IGangliaMessage

Return true iff this message contains the metadata for a metric (the metric declaration).

Specified by:

isMetricMetadata in interface IGangliaMessage

See Also:

GangliaMessageTypeEnum.METADATA

getMetricType

public GangliaMessageTypeEnum getMetricType()

Description copied from interface: IGangliaMetadataMessage

The data type declaration for the metric.

Specified by:

getMetricType in interface IGangliaMetadataMessage

getMetricName2

public String getMetricName2()

Description copied from interface: IGangliaMetadataMessage

The metric name (this is represented twice in the Ganglia 3.1 wire format: once in the metric_id header and once in the metadata record; both values SHOULD be the same).

Specified by:

getMetricName2 in interface IGangliaMetadataMessage

See Also:

IGangliaMessage.getMetricName()

getUnits

public String getUnits()

Description copied from interface: IGangliaMetadataMessage

The units in which the metric values are expressed.

Specified by:

getUnits in interface IGangliaMetadataMessage

getSlope

public GangliaSlopeEnum getSlope()

Description copied from interface: IGangliaMetadataMessage

Hint for rrdtool visualization of metric values.

Specified by:

getSlope in interface IGangliaMetadataMessage

getTMax

public int getTMax()

Description copied from interface: IGangliaMetadataMessage

The maximum advisory delay in seconds before a metric value would become stale. For the metric sending, this is also the maximum delay before it should retransmit a metric value which is unchanged from its last reported value.

Specified by:

getTMax in interface IGangliaMetadataMessage

getDMax

public int getDMax()

Description copied from interface: IGangliaMetadataMessage

The maximum age in seconds before a metric will be deleted (aka Delete Max).

Specified by:

getDMax in interface IGangliaMetadataMessage

getExtraValues

public Map<String,String[]> getExtraValues()

Description copied from interface: IGangliaMetadataMessage

Zero or more additional name-value[] pairs serialized with this message. This may be used to group metrics, add nice titles, provide in-band descriptions of metrics, etc.

Specified by:

getExtraValues in interface IGangliaMetadataMessage

getGroups

public String[] getGroups()

Description copied from interface: IGangliaMetadataMessage

Return the value of the well-known attribute IGangliaAttributes.ATTR_TITLE.

Specified by:

getGroups in interface IGangliaMetadataMessage

Returns:

The value of the TITLE attribute if present and otherwise null.

getTitle

public String getTitle()

Description copied from interface: IGangliaMetadataMessage

Return the value of the well-known attribute IGangliaAttributes.ATTR_TITLE.

Specified by:

getTitle in interface IGangliaMetadataMessage

Returns:

The value of the IGangliaAttributes.ATTR_TITLE attribute if present and otherwise null.

getDescription

public String getDescription()

Description copied from interface: IGangliaMetadataMessage

Return the value of the well-known attribute IGangliaAttributes.ATTR_DESC.

Specified by:

getDescription in interface IGangliaMetadataMessage

Returns:

The value of the IGangliaAttributes.ATTR_DESC attribute if present and otherwise null.

getFirstValue

public String getFirstValue(String key)

Description copied from interface: IGangliaMetadataMessage

Return the first value for the given key from the IGangliaMetadataMessage.getExtraValues().

Specified by:

getFirstValue in interface IGangliaMetadataMessage

Parameters:

key - The key.

Returns:

The first value for that key -or- null if there are no values for that key.

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Specified by:

equals in class AbstractGangliaMessage

hashCode

public int hashCode()

Specified by:

hashCode in class AbstractGangliaMessage

translateValue

public Object translateValue(Object value)

Return a value which may have been scaled and/or offset in order to align the value with the metric declaration. Use cases for translation include changing the units in which a metric is collected (e.g., bytes versus kilobytes) to conform with ganglia or translating the metric from an offset (e.g., 1-foo).

The default implementation is an identity transform. In order for this method to be applied the application MUST resolve metadata declarations received over the wire to local declarations in which this method has the desired behavior. This resolution step is necessary because the ganglia wire protocol is data-only and the translation steps can not be readily expressed as data (unless they are turned into a full formula evaluation model, adding substantial complexity to the ganglia integration). TODO We could also add a method which return true iff two values differ sufficient for an updated metric record to be sent out.

Specified by:

translateValue in interface IGangliaMetadataMessage

Parameters:

value - The value.

Returns:

The translated value.

isChanged

public boolean isChanged(Object oldValue,
                Object newValue)

Return true iff the newValue differs significantly from the old value.

The default implementation returns true iff the two values are not equals().

Specified by:

isChanged in interface IGangliaMetadataMessage

Parameters:

oldValue - The old value and never null.

newValue - The new value and never null.

Returns:

true iff there is a significant difference.