All Known Implementing Classes:

BaseApiTracer, OpencensusTracer
```
@InternalApi
public interface ApiTracer
```
Implementations of this class trace the logical flow of a google cloud client.
A single instance of a tracer represents a logical operation that can be annotated throughout its lifecycle. Constructing an instance of a subclass will implicitly signal the start of a new operation.
For internal use only. google-cloud-java libraries should extend BaseApiTracer.

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface ApiTracer.Scope
A context class to be used with inScope() and a try-with-resources block.

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
Modifier and Type	Method	Description
`void`	`attemptCancelled()`	Add an annotation that the attempt was cancelled by the user.
`void`	`attemptFailed(Throwable error, org.threeten.bp.Duration delay)`	Adds an annotation that the attempt failed, but another attempt will be made after the delay.
`void`	`attemptFailedRetriesExhausted(Throwable error)`	Adds an annotation that the attempt failed and that no further attempts will be made because retry limits have been reached.
`void`	`attemptPermanentFailure(Throwable error)`	Adds an annotation that the attempt failed and that no further attempts will be made because the last error was not retryable.
`void`	`attemptStarted(int attemptNumber)`	Deprecated. Please use `attemptStarted(Object, int)` instead.
`void`	`attemptStarted(Object request, int attemptNumber)`	Adds an annotation that an attempt is about to start with additional information from the request.
`void`	`attemptSucceeded()`	Adds an annotation that the attempt succeeded.
`void`	`batchRequestSent(long elementCount, long requestSize)`	Adds an annotation that a batch of writes has been flushed.
`void`	`connectionSelected(String id)`	Annotates the operation with selected connection id from the `ChannelPool`.
`ApiTracer.Scope`	`inScope()`	Asks the underlying implementation to install itself as a thread local.
`void`	`lroStartFailed(Throwable error)`	Signals that the initial RPC for the long running operation failed.
`void`	`lroStartSucceeded()`	Signals that the initial RPC successfully started the long running operation.
`void`	`operationCancelled()`	Signals that the operation was cancelled by the user.
`void`	`operationFailed(Throwable error)`	Signals that the overall operation has failed and no further attempts will be made.
`void`	`operationSucceeded()`	Signals that the overall operation has finished successfully.
`void`	`requestSent()`	Adds an annotation that a streaming request has been sent.
`void`	`responseReceived()`	Adds an annotation that a streaming response has been received.

- Method Detail
  - inScope
```
ApiTracer.Scope inScope()
```
    Asks the underlying implementation to install itself as a thread local. This allows for interop between clients using gax and external resources to share the same implementation of the tracing. For example OpenCensus will install a thread local that can read by the GRPC.
  - operationSucceeded
```
void operationSucceeded()
```
    Signals that the overall operation has finished successfully. The tracer is now considered closed and should no longer be used.
  - operationCancelled
```
void operationCancelled()
```
    Signals that the operation was cancelled by the user. The tracer is now considered closed and should no longer be used.
  - operationFailed
```
void operationFailed(Throwable error)
```
    Signals that the overall operation has failed and no further attempts will be made. The tracer is now considered closed and should no longer be used.
    
    Parameters:
    
    error - the final error that caused the operation to fail.
  - connectionSelected
```
void connectionSelected(String id)
```
    Annotates the operation with selected connection id from the ChannelPool.
    
    Parameters:
    
    id - the local connection identifier of the selected connection.
  - attemptStarted
```
@Deprecated
void attemptStarted(int attemptNumber)
```
    Deprecated.
    Please use attemptStarted(Object, int) instead.
    
    Adds an annotation that an attempt is about to start. In general this should occur at the very start of the operation. The attemptNumber is zero based. So the initial attempt will be 0.
    
    Parameters:
    
    attemptNumber - the zero based sequential attempt number.
  - attemptStarted
```
void attemptStarted(Object request,
                    int attemptNumber)
```
    Adds an annotation that an attempt is about to start with additional information from the request. In general this should occur at the very start of the operation. The attemptNumber is zero based. So the initial attempt will be 0.
    
    Parameters:
    
    attemptNumber - the zero based sequential attempt number.
    
    request - request of this attempt.
  - attemptSucceeded
```
void attemptSucceeded()
```
    Adds an annotation that the attempt succeeded.
  - attemptCancelled
```
void attemptCancelled()
```
    Add an annotation that the attempt was cancelled by the user.
  - attemptFailed
```
void attemptFailed(Throwable error,
                   org.threeten.bp.Duration delay)
```
    Adds an annotation that the attempt failed, but another attempt will be made after the delay.
    
    Parameters:
    
    error - the transient error that caused the attempt to fail.
    
    delay - the amount of time to wait before the next attempt will start.
  - attemptFailedRetriesExhausted
```
void attemptFailedRetriesExhausted(Throwable error)
```
    Adds an annotation that the attempt failed and that no further attempts will be made because retry limits have been reached.
    
    Parameters:
    
    error - the last error received before retries were exhausted.
  - attemptPermanentFailure
```
void attemptPermanentFailure(Throwable error)
```
    Adds an annotation that the attempt failed and that no further attempts will be made because the last error was not retryable.
    
    Parameters:
    
    error - the error that caused the final attempt to fail.
  - lroStartFailed
```
void lroStartFailed(Throwable error)
```
    Signals that the initial RPC for the long running operation failed.
    
    Parameters:
    
    error - the error that caused the long running operation fail.
  - lroStartSucceeded
```
void lroStartSucceeded()
```
    Signals that the initial RPC successfully started the long running operation. The long running operation will now be polled for completion.
  - responseReceived
```
void responseReceived()
```
    Adds an annotation that a streaming response has been received.
  - requestSent
```
void requestSent()
```
    Adds an annotation that a streaming request has been sent.
  - batchRequestSent
```
void batchRequestSent(long elementCount,
                      long requestSize)
```
    Adds an annotation that a batch of writes has been flushed.
    
    Parameters:
    
    elementCount - the number of elements in the batch.
    
    requestSize - the size of the batch in bytes.

Interface ApiTracer

Nested Class Summary

Method Summary

Method Detail

inScope

operationSucceeded

operationCancelled

operationFailed

connectionSelected

attemptStarted

attemptStarted

attemptSucceeded

attemptCancelled

attemptFailed

attemptFailedRetriesExhausted

attemptPermanentFailure

lroStartFailed

lroStartSucceeded

responseReceived

requestSent

batchRequestSent