Use DescribeDBInstances with an AWS SDK

The following code examples show how to use DescribeDBInstances.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example:

• Learn the basics

Java

SDK for Java 2.x

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

    /**
     * Checks the status of a Neptune instance recursively until the desired status is reached or a timeout occurs.
     *
     * @param instanceId     the ID of the Neptune instance to check
     * @param desiredStatus  the desired status of the Neptune instance
     * @param startTime      the start time of the operation, used to calculate the elapsed time
     * @param future         a {@link CompletableFuture} that will be completed when the desired status is reached
     */
    private void checkStatusRecursive(String instanceId, String desiredStatus, long startTime, CompletableFuture<Void> future) {
        DescribeDbInstancesRequest request = DescribeDbInstancesRequest.builder()
                .dbInstanceIdentifier(instanceId)
                .build();

        getAsyncClient().describeDBInstances(request)
                .whenComplete((response, exception) -> {
                    if (exception != null) {
                        Throwable cause = exception.getCause();
                        future.completeExceptionally(
                                new CompletionException("Error checking Neptune instance status", cause)
                        );
                        return;
                    }

                    List<DBInstance> instances = response.dbInstances();
                    if (instances.isEmpty()) {
                        future.completeExceptionally(new RuntimeException("Instance not found: " + instanceId));
                        return;
                    }

                    String currentStatus = instances.get(0).dbInstanceStatus();
                    long elapsedSeconds = (System.currentTimeMillis() - startTime) / 1000;
                    System.out.printf("\r Elapsed: %-20s  Status: %-20s", formatElapsedTime((int) elapsedSeconds), currentStatus);
                    System.out.flush();

                    if (desiredStatus.equalsIgnoreCase(currentStatus)) {
                        System.out.printf("\r Neptune instance reached desired status '%s' after %s.\n", desiredStatus, formatElapsedTime((int) elapsedSeconds));
                        future.complete(null);
                    } else {
                        CompletableFuture.delayedExecutor(20, TimeUnit.SECONDS)
                                .execute(() -> checkStatusRecursive(instanceId, desiredStatus, startTime, future));
                    }
                });
    }

• For API details, see DescribeDBInstances in AWS SDK for Java 2.x API Reference.

Python

SDK for Python (Boto3)

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

def check_instance_status(neptune_client, instance_id: str, desired_status: str):
    """
    Polls the status of a Neptune DB instance until it reaches desired_status.
    Uses pagination via describe_db_instances — even for a single instance.

    Raises:
      ClientError: If describe_db_instances fails (e.g., instance not found).
      RuntimeError: If timeout expires before reaching desired status.
    """
    paginator = neptune_client.get_paginator('describe_db_instances')
    start_time = time.time()

    while True:
        try:
            pages = paginator.paginate(DBInstanceIdentifier=instance_id)
            instances = []
            for page in pages:
                instances.extend(page.get('DBInstances', []))

        except ClientError as err:
            code = err.response["Error"]["Code"]
            message = err.response["Error"]["Message"]

            if code == "DBInstanceNotFound":
                print(f"Instance '{instance_id}' not found. Please verify the instance ID.")
            else:
                print(f"Failed to describe DB instance. {code}: {message}")
            raise

        current_status = instances[0].get('DBInstanceStatus') if instances else None
        elapsed = int(time.time() - start_time)

        print(f"\rElapsed: {format_elapsed_time(elapsed)}  Status: {current_status}", end="", flush=True)

        if current_status and current_status.lower() == desired_status.lower():
            print(f"\nInstance '{instance_id}' reached '{desired_status}' in {format_elapsed_time(elapsed)}.")
            return

        if elapsed > TIMEOUT_SECONDS:
            raise RuntimeError(f"Timeout waiting for '{instance_id}' to reach '{desired_status}'")

        time.sleep(POLL_INTERVAL_SECONDS)

• For API details, see DescribeDBInstances in AWS SDK for Python (Boto3) API Reference.