Package io.opencensus.metrics
Class DoubleGauge
java.lang.Object
io.opencensus.metrics.DoubleGauge
- Direct Known Subclasses:
DoubleGauge.NoopDoubleGauge
,DoubleGaugeImpl
Double Gauge metric, to report instantaneous measurement of a double value. Gauges can go both up
and down. The gauges values can be negative.
Example 1: Create a Gauge with default labels.
class YourClass {
private static final MetricRegistry metricRegistry = Metrics.getMetricRegistry();
List<LabelKey> labelKeys = Arrays.asList(LabelKey.create("Name", "desc"));
DoubleGauge gauge = metricRegistry.addDoubleGauge("queue_size",
"Pending jobs", "1", labelKeys);
// It is recommended to keep a reference of a point for manual operations.
DoublePoint defaultPoint = gauge.getDefaultTimeSeries();
void doWork() {
// Your code here.
defaultPoint.add(10);
}
}
Example 2: You can also use labels(keys and values) to track different types of metric.
class YourClass {
private static final MetricRegistry metricRegistry = Metrics.getMetricRegistry();
List<LabelKey> labelKeys = Arrays.asList(LabelKey.create("Name", "desc"));
List<LabelValue> labelValues = Arrays.asList(LabelValue.create("Inbound"));
DoubleGauge gauge = metricRegistry.addDoubleGauge("queue_size",
"Pending jobs", "1", labelKeys);
// It is recommended to keep a reference of a point for manual operations.
DoublePoint inboundPoint = gauge.getOrCreateTimeSeries(labelValues);
void doSomeWork() {
// Your code here.
inboundPoint.set(15);
}
}
- Since:
- 0.17
-
Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic class
The value of a single point in the Gauge.TimeSeries.private static final class
No-op implementations of DoubleGauge class. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionabstract void
clear()
Removes allTimeSeries
from the gauge metric.abstract DoubleGauge.DoublePoint
Returns aDoublePoint
for a gauge with all labels not set, or default labels.abstract DoubleGauge.DoublePoint
getOrCreateTimeSeries
(List<LabelValue> labelValues) Creates aTimeSeries
and returns aDoublePoint
if the specifiedlabelValues
is not already associated with this gauge, else returns an existingDoublePoint
.(package private) static DoubleGauge
Returns the no-op implementation of theDoubleGauge
.abstract void
removeTimeSeries
(List<LabelValue> labelValues) Removes theTimeSeries
from the gauge metric, if it is present.
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Constructor Details
-
DoubleGauge
public DoubleGauge()
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-
Method Details
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getOrCreateTimeSeries
Creates aTimeSeries
and returns aDoublePoint
if the specifiedlabelValues
is not already associated with this gauge, else returns an existingDoublePoint
.It is recommended to keep a reference to the DoublePoint instead of always calling this method for manual operations.
- Parameters:
labelValues
- the list of label values. The number of label values must be the same to that of the label keys passed toMetricRegistry.addDoubleGauge(java.lang.String, java.lang.String, java.lang.String, java.util.List<io.opencensus.metrics.LabelKey>)
.- Returns:
- a
DoublePoint
the value of single gauge. - Throws:
NullPointerException
- iflabelValues
is null OR any element oflabelValues
is null.IllegalArgumentException
- if number oflabelValues
s are not equal to the label keys.- Since:
- 0.17
-
getDefaultTimeSeries
Returns aDoublePoint
for a gauge with all labels not set, or default labels.- Returns:
- a
DoublePoint
for a gauge with all labels not set, or default labels. - Since:
- 0.17
-
removeTimeSeries
Removes theTimeSeries
from the gauge metric, if it is present. i.e. references to previousDoublePoint
objects are invalid (not part of the metric).- Parameters:
labelValues
- the list of label values.- Throws:
NullPointerException
- iflabelValues
is null or any element oflabelValues
is null.- Since:
- 0.17
-
clear
public abstract void clear()Removes allTimeSeries
from the gauge metric. i.e. references to all previousDoublePoint
objects are invalid (not part of the metric).- Since:
- 0.17
-
newNoopDoubleGauge
static DoubleGauge newNoopDoubleGauge(String name, String description, String unit, List<LabelKey> labelKeys) Returns the no-op implementation of theDoubleGauge
.- Returns:
- the no-op implementation of the
DoubleGauge
. - Since:
- 0.17
-