ParameterizedSampler (Brave 5.13.9 API)

java.lang.Object
- brave.sampler.ParameterizedSampler<P>

Type Parameters:

P - The type that encloses parameters associated with a sample rate. For example, this could be a pair of http and method.

All Implemented Interfaces:

SamplerFunction<P>
```
public final class ParameterizedSampler<P>
extends Object
implements SamplerFunction<P>
```
This is an implementation of how to decide whether to trace a request using ordered rules. For example, you could write rules to look at an HTTP method and path, or a RabbitMQ routing key and queue name.
This looks at runtime parameters to see if they match a rule. If all calls to a java method should have the same sample rate, consider DeclarativeSampler instead.

Since:

4.4

See Also:

Matcher

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`ParameterizedSampler.Builder<P>`
`static class`	`ParameterizedSampler.Rule<P>`	Deprecated. Since 5.8, use `ParameterizedSampler.Builder.putRule(Matcher, Sampler)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`static <P> ParameterizedSampler<P>`	`create(List<? extends ParameterizedSampler.Rule<P>> rules)`	Deprecated. since 5.8, use `newBuilder()`
`static <P> ParameterizedSampler.Builder<P>`	`newBuilder()`
`SamplingFlags`	`sample(P parameters)`	Deprecated. Since 5.8, use `trySample(Object)`
`Boolean`	`trySample(P parameters)`	Returns an overriding sampling decision for a new trace.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - newBuilder
```
public static <P> ParameterizedSampler.Builder<P> newBuilder()
```
    Since:
    
    5.8
  - trySample
```
@Nullable
public Boolean trySample(P parameters)
```
    Returns an overriding sampling decision for a new trace. Returning null is typically used to defer to the trace ID sampler.
    
    Specified by:
    
    trySample in interface SamplerFunction<P>
    
    Parameters:
    
    parameters - parameter to evaluate for a sampling decision. null input results in a null result
    
    Returns:
    
    true to sample a new trace or false to deny. Null defers the decision.
    
    Since:
    
    5.8
  - sample
```
@Deprecated
public SamplingFlags sample(@Nullable
                            P parameters)
```
    Deprecated.
    Since 5.8, use trySample(Object)
    
    Since:
    
    4.4
  - create
```
@Deprecated
public static <P> ParameterizedSampler<P> create(List<? extends ParameterizedSampler.Rule<P>> rules)
```
    Deprecated.
    since 5.8, use newBuilder()
    
    Since:
    
    4.4