La generación de archivos de datos estructurados (SDF) puede durar desde unos segundos hasta horas. La tarea se realiza cuando el done campo en el Operation es
True.
Una Operation se identifica con un nombre en el formato /sdfdownloadtasks/operations/{id}. Recupera periódicamente el Operation con
este nombre usando sdfdownloadtasks.operations.get para ver si
la tarea finalizó. Este proceso se conoce como "sondeo".
Si done es True, se establecerá el campo response o
error. Una tarea fallida establece el error
campo. El objeto Status asignado proporciona detalles sobre la
falla. Una tarea exitosa establece el response campo. Descarga los SDF resultantes de response.resourceName.
El sondeo ineficiente puede consumir una gran cantidad de cuota de solicitudes a la API. Limita los reintentos y conserva la cuota con una retirada exponencial.
A continuación, se muestra cómo sondear una tarea de descarga de SDF con una retirada exponencial:
Java
// Provide the name of the sdfdownloadtask operation. String operationName = operation-name; // Configure the Operations.get request. Sdfdownloadtasks.Operations.Get operationRequest = service.sdfdownloadtasks().operations().get(operationName); // Configure exponential backoff for checking the status of our operation. ExponentialBackOff backOff = new ExponentialBackOff.Builder() .setInitialIntervalMillis(5000) // setting initial interval to five seconds .setMaxIntervalMillis(5000 * 60) // setting max interval to five minutes .setMaxElapsedTimeMillis(5000 * 60 * 60) // setting max elapsed time to five hours .build(); long backoffMillis = 0; // Create default operation variable. Operation operation = new Operation(); do { // Sleep before retrieving operation again. Thread.sleep(backoffMillis); // Retrieve operation. operation = operationRequest.execute(); // If operation is not done, calculate next sleep period. if (operation.getDone() == null) { backoffMillis = backOff.nextBackOffMillis(); if (backoffMillis == ExponentialBackOff.STOP) { System.out.printf("The operation has taken more than five hours to complete.%n"); break; } System.out.printf( "Operation %s is still running, sleeping for %s milliseconds.%n", operationName, backoffMillis); } } while (operation.getDone() == null); // Check whether operation finished with an error, or is completed and ready to download. if (operation.getDone() != null) { if (operation.getError() != null) { System.out.printf( "The operation finished in error with code %s: %s%n", operation.getError().getCode(), operation.getError().getMessage()); } else { System.out.printf( "The operation completed successfully. Resource %s was created.%n", operation.getResponse().get("resourceName").toString()); } }
Python
# Provide the name of the sdfdownloadtask operation. operation_name = operation-name # Set the following values that control retry behavior while the operation # is running. # Minimum amount of time between polling requests. Defaults to 5 seconds. min_retry_interval = 5 # Maximum amount of time between polling requests. Defaults to 5 minutes. max_retry_interval = 5 * 60 # Maximum amount of time to spend polling. Defaults to 5 hours. max_retry_elapsed_time = 5 * 60 * 60 def next_sleep_interval(previous_sleep_interval): """Calculates the next sleep interval based on the previous.""" min_interval = previous_sleep_interval or min_retry_interval max_interval = previous_sleep_interval * 3 or min_retry_interval return min(max_retry_interval, random.randint(min_interval, max_interval)) # Configure the sdfdownloadtasks.operations.get request. get_request = service.sdfdownloadtasks().operations().get(name=operation_name) sleep = 0 start_time = time.time() while True: # Retrieve the operation. operation = get_request.execute() if "done" in operation: if "error" in operation: print( f"The operation finished in error with code " f'{operation["error"]["code"]}: {operation["error"]["message"]}' ) else: print( f"The operation completed successfully. The resulting files can be " f'downloaded at {operation["response"]["resourceName"]}.' ) break elif time.time() - start_time > max_retry_elapsed_time: print("SDF generation deadline exceeded.") break sleep = next_sleep_interval(sleep) print( f"Operation {operation_name} is still running, sleeping for " f"{sleep} seconds." ) time.sleep(sleep)
PHP
// The following values control retry behavior while the task is processing. // Minimum amount of time between polling requests. Defaults to 5 seconds. $minRetryInterval = 5; // Maximum amount of time between polling requests. Defaults to 5 minutes. $maxRetryInterval = 300; // Maximum amount of time to spend polling. Defaults to 5 hours. $maxRetryElapsedTime = 18000; // Provide the name of the sdfdownloadtask operation. $operationName = operation-name; // Poll operation. $sleep = 0; $startTime = time(); do { try { // Call the API, retrieving the SDF Download Task. $operation = $this->service->sdfdownloadtasks_operations->get( $operationName ); } catch (\Exception $e) { $this->renderError($e); return; } // Check if retrieved operation is finished. if ($operation->getDone() === true) { if($operation->getError() !== null) { $error = $operation->getError(); printf( 'The operation finished in error with code %s: %s<br>', $error->setCode(), $error->setMessage() ); break; } else { $response = $operation->getResponse(); printf( 'The operation completed successfully. Resource %s ' . 'was created.<br>', $response['resourceName'] ); break; } } elseif (time() - $startTime > self::MAX_RETRY_ELAPSED_TIME) { print '<p>SDF download task processing deadline exceeded</p>'; break; } // Generate next sleep interval. $minInterval = max($minRetryInterval, $sleep); $maxInterval = max( $minRetryInterval, $sleep * 3 ); $sleep = min($maxRetryInterval, rand($minInterval, $maxInterval)); // Sleep a determined amount of time before retrieving the operation // again. printf( 'Operation %s is still running, sleeping for %d seconds<br>', $operationName, $sleep ); sleep($sleep); } while (true);