jrunx.metrics
Interface Metrics

All Superinterfaces:

MetricsConstants, MetricsServiceMBean, java.io.Serializable, Service, ServiceMBean

All Known Implementing Classes:

MetricsService

public interface Metrics

extends MetricsServiceMBean, MetricsConstants

Metrics container interface. Numeric metrics for the server are kept in this container.

Fields inherited from interface jrunx.kernel.Service

INITIALIZED, STARTED, STARTING, STOPPED, STOPPING, UNINITIALIZED

Fields inherited from interface jrunx.metrics.MetricsConstants

METRICS_BUSY_TH, METRICS_DELAY_MS, METRICS_DELAY_RQ, METRICS_DELAY_TH, METRICS_DROPPED_RQ, METRICS_FREE_MEMORY, METRICS_IDLE_TH, METRICS_LISTEN_TH, METRICS_TOTAL_MEMORY, METRICS_TOTAL_TH

Method Summary

int	createMetric(java.lang.String name) create a metric with the given name
int	createMetric(java.lang.String name, boolean reset) create a metric with the given name.
java.util.Properties	createProperties(int[] values) Create a Properties object with the metrics name as the key and the given values as the corresponding element.
void	deleteMetric(java.lang.String name) remove a metric by name
int[]	exchangeMetrics(int[] values) swap metrics arrays atomically.
int	findMetric(java.lang.String name) look up a metric by name
int	getMetric(int index) obtain the value of a metric
int[]	getSnapshot() Take a snapshot of the current metrics.
int[]	getSnapshot(boolean reset) Take a snapshot of the current metrics.
java.util.Vector	getSnapshotHistory() Returns the snapshot history.
long	getSnapshotTime() Returns the timestamp of the last snapshot.
boolean	isReset(java.lang.String name) Determine if the metric should be reset when a snapshot is taken
void	setMetric(int index, int value) change the value of a metric
int	updateMetric(int index, int delta) update the value of a metric by adding the given delta value in an atomic operation.

Methods inherited from interface jrunx.metrics.MetricsServiceMBean

getHistorySize, getInitialSize, getMetricsService, setHistorySize, setInitialSize

Methods inherited from interface jrunx.kernel.ServiceMBean

bind, getBindToJNDI, getDeactivated, getDomainName, getJRunService, getLogger, getName, getParentService, getServerName, requestServer, setBindToJNDI, setDeactivated, setDomainName, setName, setParentService, unbind

Methods inherited from interface jrunx.kernel.Service

destroy, getStatus, init, start, stop, updateStatus

Method Detail

createMetric

public int createMetric(java.lang.String name)

create a metric with the given name

Parameters:

the - name of the metric

Returns:

index of the new metric

createMetric

public int createMetric(java.lang.String name,
                        boolean reset)

create a metric with the given name. If the 'reset' value is true then the value will be reset after logging

Parameters:

name - the name of the metric

reset - true if the value should be reset after logging

Returns:

index of the new metric

setMetric

public void setMetric(int index,
                      int value)

change the value of a metric

Parameters:

index - metric to be updated

value - the new value

getMetric

public int getMetric(int index)

obtain the value of a metric

Parameters:

index - metric to be fetched

updateMetric

public int updateMetric(int index,
                        int delta)

update the value of a metric by adding the given delta value in an atomic operation.

Parameters:

index - the metric index

Returns:

the new metric value, equal to [old-value] + delta

findMetric

public int findMetric(java.lang.String name)

look up a metric by name

Parameters:

the - name

Returns:

the index of the metric, or -1 if not found

deleteMetric

public void deleteMetric(java.lang.String name)

remove a metric by name

Parameters:

name - String name of the metric to be deleted

exchangeMetrics

public int[] exchangeMetrics(int[] values)

swap metrics arrays atomically. This method can be used to efficiently take a snapshot of the current metrics. A separate entity can maintain a set of buffers and rotate them in and out of the metrics manager.

Parameters:

values - an old buffer to install

Returns:

the current buffer with the latest values

getSnapshot

public int[] getSnapshot()

Take a snapshot of the current metrics.

Returns:

The current metrics

getSnapshot

public int[] getSnapshot(boolean reset)

Take a snapshot of the current metrics. Optionally reset any metrics that should be reset (reset flag true on createMetric).

Parameters:

reset - true if the metrics should be reset

Returns:

The current metrics

getSnapshotTime

public long getSnapshotTime()

Returns the timestamp of the last snapshot. This can be used to determine the current elapsed time of the metrics that are reset

Returns:

The last time a snapshot (and reset) was performed

getSnapshotHistory

public java.util.Vector getSnapshotHistory()

Returns the snapshot history. The history is returned as a Vector of MetricsSnapshot objects, with the first element being the most recent and the last element being the oldest.

Returns:

The vector of MetricsSnapshot objects

createProperties

public java.util.Properties createProperties(int[] values)

Create a Properties object with the metrics name as the key and the given values as the corresponding element.

Parameters:

The - values

Returns:

The Properties object

isReset

public boolean isReset(java.lang.String name)

Determine if the metric should be reset when a snapshot is taken

Parameters:

name - The metric name

Returns:

true if the metric should be reset