org.hawkular.metrics.alerter

Enum ConditionExpression.EvalType

java.lang.Object

java.lang.Enum<ConditionExpression.EvalType>

org.hawkular.metrics.alerter.ConditionExpression.EvalType

All Implemented Interfaces:

Serializable, Comparable<ConditionExpression.EvalType>

Enclosing class:

ConditionExpression

public static enum ConditionExpression.EvalType
extends Enum<ConditionExpression.EvalType>

Determines whether the eval expression is performed on ALL or EACH of the metrics. The ConditionExpression.Query.metrics and ConditionExpression.Query.tags fields define the set of metrics will be involved in the query. The query will result in a set of data points for each metric. This field defines how to perform the ConditionExpression.eval for the resulting data points.

ALL means that the data points for all of the metrics will be combined, then aggregated, and ConditionExpression.eval is resolved one time (per run of the ConditionExpression). At most one Event will be sent to Alerting if ConditionExpression.eval resolves to true.

EACH means that the data points for each metric will be aggregated separately. ConditionExpression.eval is resolved N times, once for each metric. Up to N Events could be sent to Alerting depending on how often ConditionExpression.eval resolves to true.

For example, assume we are dealing with two metrics, M1 and M2, the eval is "q(qNow,avg) > 100", and qNow is define with an interval of 1h. On each run we get the M1 and M2 data points for the most recent hour. Using ALL we combine all of the datapoints, generate the average, and resolve the expression. If true we send an Event to alerting. Using EACH we keep the data points for each metric separate, generate the average for each, and resolve the expression for each. For each true resolution we send an Event to Alerting. Note that to distinguish the events we provide the metric name in the Event context. For example, like context={"MetricName":"M1"}.

A Note tabout using EACH/b>. If multiple queries are involved in the eval expression then that only metrics common to each query will be evaluated. For example, if the eval abbove were "q(qNow,avg) > q(qYesterday,avg)" and only M1 were common to both queries then the eval would only be resolved using M1 data points. In general each query will likely use the same metrics so this issue is a corner case.

The default is ALL.

Enum Constant Summary

Enum Constants

Enum Constant and Description
ALL
EACH

Method Summary

Modifier and Type	Method and Description
static ConditionExpression.EvalType	valueOf(String name) Returns the enum constant of this type with the specified name.
static ConditionExpression.EvalType[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

ALL

public static final ConditionExpression.EvalType ALL

EACH

public static final ConditionExpression.EvalType EACH

Method Detail

values

public static ConditionExpression.EvalType[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ConditionExpression.EvalType c : ConditionExpression.EvalType.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ConditionExpression.EvalType valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null