使用具有有限堆的 azure-sdk-for-java 上传大文件

Question

我们正在开发需要使用 Azure 作为文件内容存储的文档微服务。Azure Block Blob 似乎是一个合理的选择。文档服务的堆限制为 512MB ( -Xmx512m)。

我没有成功地使用有限的堆上传流式文件azure-storage-blob:12.10.0-beta.1（也在 上进行了测试12.9.0）。

尝试了以下方法：

1. 使用从文档中复制粘贴BlockBlobClient

BlockBlobClient blockBlobClient = blobContainerClient.getBlobClient("file").getBlockBlobClient();

File file = new File("file");

try (InputStream dataStream = new FileInputStream(file)) {
  blockBlobClient.upload(dataStream, file.length(), true /* overwrite file */);
}

结果： java.io.IOException: mark/reset not supported - 即使文件输入流报告此功能不受支持，SDK 也会尝试使用标记/重置。

2. 添加BufferedInputStream以减轻标记/重置问题（根据建议）：

BlockBlobClient blockBlobClient = blobContainerClient.getBlobClient("file").getBlockBlobClient();

File file = new File("file");

try (InputStream dataStream = new BufferedInputStream(new FileInputStream(file))) {
  blockBlobClient.upload(dataStream, file.length(), true /* overwrite file */);
}

结果： java.lang.OutOfMemoryError: Java heap space。我假设 SDK 尝试将所有 1.17GB 的文件内容加载到内存中。

3. 更换BlockBlobClient用BlobClient和除去堆大小限制（-Xmx512m）：

BlobClient blobClient = blobContainerClient.getBlobClient("file");

File file = new File("file");

try (InputStream dataStream = new FileInputStream(file)) {
  blobClient.upload(dataStream, file.length(), true /* overwrite file */);
}

结果：使用了1.5GB 的堆内存，所有文件内容都加载到内存中 + Reactor 一侧的一些缓冲

来自 VisualVM 的堆使用

4. 通过BlobOutputStream以下方式切换到流媒体：

long blockSize = DataSize.ofMegabytes(4L).toBytes();

BlockBlobClient blockBlobClient = blobContainerClient.getBlobClient("file").getBlockBlobClient();

// create / erase blob
blockBlobClient.commitBlockList(List.of(), true);

BlockBlobOutputStreamOptions options = (new BlockBlobOutputStreamOptions()).setParallelTransferOptions(
  (new ParallelTransferOptions()).setBlockSizeLong(blockSize).setMaxConcurrency(1).setMaxSingleUploadSizeLong(blockSize));

try (InputStream is = new FileInputStream("file")) {
  try (OutputStream os = blockBlobClient.getBlobOutputStream(options)) {
    IOUtils.copy(is, os); // uses 8KB buffer
  }
}

结果：文件在上传过程中损坏。Azure Web 门户显示 1.09GB，而不是预期的 1.17GB。从 Azure Web 门户手动下载文件可确认文件内容在上传过程中已损坏。内存占用显着减少，但文件损坏是一个阻碍。

问题：无法提出内存占用小的有效上传/下载解决方案

任何帮助将不胜感激！

Answer 1

请尝试下面的代码来上传/下载大文件，我已经使用大小约为 1.1 GB 的 .zip 文件进行了测试

对于上传文件：

public static void uploadFilesByChunk() {
                String connString = "<conn str>";
                String containerName = "<container name>";
                String blobName = "UploadOne.zip";
                String filePath = "D:/temp/" + blobName;

                BlobServiceClient client = new BlobServiceClientBuilder().connectionString(connString).buildClient();
                BlobClient blobClient = client.getBlobContainerClient(containerName).getBlobClient(blobName);
                long blockSize = 2 * 1024 * 1024; //2MB
                ParallelTransferOptions parallelTransferOptions = new ParallelTransferOptions()
                                .setBlockSizeLong(blockSize).setMaxConcurrency(2)
                                .setProgressReceiver(new ProgressReceiver() {
                                        @Override
                                        public void reportProgress(long bytesTransferred) {
                                                System.out.println("uploaded:" + bytesTransferred);
                                        }
                                });

                BlobHttpHeaders headers = new BlobHttpHeaders().setContentLanguage("en-US").setContentType("binary");

                blobClient.uploadFromFile(filePath, parallelTransferOptions, headers, null, AccessTier.HOT,
                                new BlobRequestConditions(), Duration.ofMinutes(30));
        }

内存占用：

对于下载文件：

public static void downLoadFilesByChunk() {
                String connString = "<conn str>";
                String containerName = "<container name>";
                String blobName = "UploadOne.zip";

                String filePath = "D:/temp/" + "DownloadOne.zip";

                BlobServiceClient client = new BlobServiceClientBuilder().connectionString(connString).buildClient();
                BlobClient blobClient = client.getBlobContainerClient(containerName).getBlobClient(blobName);
                long blockSize = 2 * 1024 * 1024;
                com.azure.storage.common.ParallelTransferOptions parallelTransferOptions = new com.azure.storage.common.ParallelTransferOptions()
                                .setBlockSizeLong(blockSize).setMaxConcurrency(2)
                                .setProgressReceiver(new com.azure.storage.common.ProgressReceiver() {
                                        @Override
                                        public void reportProgress(long bytesTransferred) {
                                                System.out.println("dowloaded:" + bytesTransferred);
                                        }
                                });

                BlobDownloadToFileOptions options = new BlobDownloadToFileOptions(filePath)
                                .setParallelTransferOptions(parallelTransferOptions);
                blobClient.downloadToFileWithResponse(options, Duration.ofMinutes(30), null);
        }

内存占用：

结果：