java.lang.Object
- com.google.api.gax.tracing.BaseApiTracer
- - com.google.api.gax.tracing.OpencensusTracer

All Implemented Interfaces:

ApiTracer
```
@BetaApi("Surface for tracing is not yet stable")
public class OpencensusTracer
extends BaseApiTracer
```
Implementation of ApiTracer that uses OpenCensus.
This implementation wraps an OpenCensus Span for every tracer and annotates that Span with various events throughout the lifecycle of the logical operation.
Each span will be named ClientName.MethodName and will have the following attributes:

attempt count
The Number of attempts sent before the logical operation completed
status
The status code of the last attempt
total response count
The number of messages received across all of the attempts. This will only be set for server streaming and bidi RPCs.
total request count
The number of messages sent across all of the attempts. This will only be set for client streaming and bidi RPCs.
batch count
For batch requests, the number of elements in the request.
batch size
For batch requests, the byte size of the request.

The spans will contain the following annotations:
- Attempt cancelled with the following attributes:
  
  attempt
  Zero based sequential attempt number
  attempt request count
  The number of requests sent in this attempt. This will only be set for client streaming and bidi RPCs.
  attempt response count
  The number of responses received in this attempt. This will only be set for server streaming and bidi RPCs.
  connection
  The UUID of the connection which the attempt was sent.
- Attempt failed, scheduling next attempt with the following attributes:
  
  attempt
  Zero based sequential attempt number
  status
  The status code of the failed attempt
  delay
  The number of milliseconds to wait before trying again
  attempt request count
  The number of requests sent in this attempt. This will only be set for client streaming and bidi RPCs.
  attempt response count
  The number of responses received in this attempt. This will only be set for server streaming and bidi RPCs.
  connection
  The UUID of the connection which the attempt was sent.
- Attempts exhausted with the following attributes:
  
  attempt
  Zero based sequential attempt number
  status
  The status code of the failed attempt
  attempt request count
  The number of requests sent in this attempt. This will only be set for client streaming and bidi RPCs.
  attempt response count
  The number of responses received in this attempt. This will only be set for server streaming and bidi RPCs.
  connection
  The UUID of the connection which the attempt was sent.
- Attempt failed, error not retryable with the following attributes:
  
  attempt
  Zero based sequential attempt number
  status
  The status code of the failed attempt
  attempt request count
  The number of requests sent in this attempt. This will only be set for client streaming and bidi RPCs.
  attempt response count
  The number of responses received in this attempt. This will only be set for server streaming and bidi RPCs.
  connection
  The UUID of the connection which the attempt was sent.
- Attempt succeeded with the following attributes:
  
  attempt
  Zero based sequential attempt number
  attempt request count
  The number of requests sent in this attempt. This will only be set for client streaming and bidi RPCs.
  attempt response count
  The number of responses received in this attempt. This will only be set for server streaming and bidi RPCs.
  connection
  The UUID of the connection which the attempt was sent.
Long running operations, which are composed of an initial RPC to start the operation and a number of polling RPCs will be represented as a tree of spans. The top level span will be named after the initial RPC name suffixed with "Operation" and will have the following annotations:
- Operation started
- Operation failed to start with the following attributes:
  
  status
  The status code of why the operation failed to start
- Polling was cancelled with the following attributes:
  
  attempt
  Zero based sequential poll number.
  attempt request count
- Scheduling next poll with the following attributes:
  
  attempt
  Zero based sequential poll number
  status
  OK if the poll succeeded, but the operation is still running.
  delay
  The number of milliseconds to wait before polling again
- Polling attempts exhausted with the following attributes:
  
  attempt
  Zero based sequential poll number
  status
  OK if the poll succeeded, but the operation is still running.
- Polling failed with the following attributes:
  
  attempt
  Zero based sequential poll number
  status
  OK if the poll succeeded, but the operation is still running.
- Polling completed with the following attributes:
  
  attempt
  Zero based sequential poll number
The toplevel long running operation span will also contain child spans to describe the retry attempts for the initial RPC and each poll as described in the general span section above.
This class is thread compatible. It expects callers to follow grpc's threading model: there is only one thread that invokes the operation* and attempt* methods. Please see ApiStreamObserver for more information.

Nested Class Summary
- Nested classes/interfaces inherited from interface com.google.api.gax.tracing.ApiTracer
  ApiTracer.Scope

Method Summary

All Methods Instance Methods Concrete 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)`	Adds an annotation that an attempt is about to start.
`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.

Methods inherited from class com.google.api.gax.tracing.BaseApiTracer
getInstance

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

- Method Detail
  - inScope
```
public 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.
    
    Specified by:
    
    inScope in interface ApiTracer
    
    Overrides:
    
    inScope in class BaseApiTracer
  - operationSucceeded
```
public void operationSucceeded()
```
    Signals that the overall operation has finished successfully. The tracer is now considered closed and should no longer be used.
    
    Specified by:
    
    operationSucceeded in interface ApiTracer
    
    Overrides:
    
    operationSucceeded in class BaseApiTracer
  - operationCancelled
```
public void operationCancelled()
```
    Signals that the operation was cancelled by the user. The tracer is now considered closed and should no longer be used.
    
    Specified by:
    
    operationCancelled in interface ApiTracer
    
    Overrides:
    
    operationCancelled in class BaseApiTracer
  - operationFailed
```
public 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.
    
    Specified by:
    
    operationFailed in interface ApiTracer
    
    Overrides:
    
    operationFailed in class BaseApiTracer
    
    Parameters:
    
    error - the final error that caused the operation to fail.
  - lroStartFailed
```
public void lroStartFailed(Throwable error)
```
    Signals that the initial RPC for the long running operation failed.
    
    Specified by:
    
    lroStartFailed in interface ApiTracer
    
    Overrides:
    
    lroStartFailed in class BaseApiTracer
    
    Parameters:
    
    error - the error that caused the long running operation fail.
  - lroStartSucceeded
```
public void lroStartSucceeded()
```
    Signals that the initial RPC successfully started the long running operation. The long running operation will now be polled for completion.
    
    Specified by:
    
    lroStartSucceeded in interface ApiTracer
    
    Overrides:
    
    lroStartSucceeded in class BaseApiTracer
  - connectionSelected
```
public void connectionSelected(String id)
```
    Annotates the operation with selected connection id from the ChannelPool.
    
    Specified by:
    
    connectionSelected in interface ApiTracer
    
    Overrides:
    
    connectionSelected in class BaseApiTracer
    
    Parameters:
    
    id - the local connection identifier of the selected connection.
  - attemptStarted
```
public void attemptStarted(int attemptNumber)
```
    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.
    
    Specified by:
    
    attemptStarted in interface ApiTracer
    
    Overrides:
    
    attemptStarted in class BaseApiTracer
    
    Parameters:
    
    attemptNumber - the zero based sequential attempt number.
  - attemptStarted
```
public 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.
    
    Specified by:
    
    attemptStarted in interface ApiTracer
    
    Overrides:
    
    attemptStarted in class BaseApiTracer
    
    Parameters:
    
    request - request of this attempt.
    
    attemptNumber - the zero based sequential attempt number.
  - attemptSucceeded
```
public void attemptSucceeded()
```
    Adds an annotation that the attempt succeeded.
    
    Specified by:
    
    attemptSucceeded in interface ApiTracer
    
    Overrides:
    
    attemptSucceeded in class BaseApiTracer
  - attemptCancelled
```
public void attemptCancelled()
```
    Add an annotation that the attempt was cancelled by the user.
    
    Specified by:
    
    attemptCancelled in interface ApiTracer
    
    Overrides:
    
    attemptCancelled in class BaseApiTracer
  - attemptFailed
```
public 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.
    
    Specified by:
    
    attemptFailed in interface ApiTracer
    
    Overrides:
    
    attemptFailed in class BaseApiTracer
    
    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
```
public 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.
    
    Specified by:
    
    attemptFailedRetriesExhausted in interface ApiTracer
    
    Overrides:
    
    attemptFailedRetriesExhausted in class BaseApiTracer
    
    Parameters:
    
    error - the last error received before retries were exhausted.
  - attemptPermanentFailure
```
public 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.
    
    Specified by:
    
    attemptPermanentFailure in interface ApiTracer
    
    Overrides:
    
    attemptPermanentFailure in class BaseApiTracer
    
    Parameters:
    
    error - the error that caused the final attempt to fail.
  - responseReceived
```
public void responseReceived()
```
    Adds an annotation that a streaming response has been received.
    
    Specified by:
    
    responseReceived in interface ApiTracer
    
    Overrides:
    
    responseReceived in class BaseApiTracer
  - requestSent
```
public void requestSent()
```
    Adds an annotation that a streaming request has been sent.
    
    Specified by:
    
    requestSent in interface ApiTracer
    
    Overrides:
    
    requestSent in class BaseApiTracer
  - batchRequestSent
```
public void batchRequestSent(long elementCount,
                             long requestSize)
```
    Adds an annotation that a batch of writes has been flushed.
    
    Specified by:
    
    batchRequestSent in interface ApiTracer
    
    Overrides:
    
    batchRequestSent in class BaseApiTracer
    
    Parameters:
    
    elementCount - the number of elements in the batch.
    
    requestSize - the size of the batch in bytes.

Class OpencensusTracer

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.api.gax.tracing.ApiTracer

Method Summary

Methods inherited from class com.google.api.gax.tracing.BaseApiTracer

Methods inherited from class java.lang.Object

Method Detail

inScope

operationSucceeded

operationCancelled

operationFailed

lroStartFailed

lroStartSucceeded

connectionSelected

attemptStarted

attemptStarted

attemptSucceeded

attemptCancelled

attemptFailed

attemptFailedRetriesExhausted

attemptPermanentFailure

responseReceived

requestSent

batchRequestSent