public String getS3BackupMode() {
        return this.s3BackupMode;
    }
<p>
Defines how documents should be delivered to Amazon S3. When it is set to <code>FailedDocumentsOnly</code>,
Firehose writes any documents that could not be indexed to the configured Amazon S3 destination, with
<code>AmazonOpenSearchService-failed/</code> appended to the key prefix. When set to <code>AllDocuments</code>,
Firehose delivers all incoming records to Amazon S3, and also writes failed documents with
<code>AmazonOpenSearchService-failed/</code> appended to the prefix. For more information, see <a
href="https://docs.aws.amazon.com/firehose/latest/dev/basic-deliver.html#es-s3-backup">Amazon S3 Backup for the
Amazon ES Destination</a>. Default value is <code>FailedDocumentsOnly</code>.
</p>
<p>
You can't change this backup mode after you create the delivery stream.
</p>

@return Defines how documents should be delivered to Amazon S3. When it is set to
        <code>FailedDocumentsOnly</code>, Firehose writes any documents that could not be indexed to the
        configured Amazon S3 destination, with <code>AmazonOpenSearchService-failed/</code> appended to the key
        prefix. When set to <code>AllDocuments</code>, Firehose delivers all incoming records to Amazon S3, and
        also writes failed documents with <code>AmazonOpenSearchService-failed/</code> appended to the prefix.
        For more information, see <a
        href="https://docs.aws.amazon.com/firehose/latest/dev/basic-deliver.html#es-s3-backup">Amazon S3 Backup
        for the Amazon ES Destination</a>. Default value is <code>FailedDocumentsOnly</code>.</p>
        <p>
        You can't change this backup mode after you create the delivery stream.
@see ElasticsearchS3BackupMode
aws-java-sdk-kinesis/src/main/java/com/amazonaws/services/kinesisfirehose/model/ElasticsearchDestinationConfiguration.java