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Storage: Fix slow download performance #5791

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Merged
ajaaym merged 8 commits into from
Jul 31, 2019
Merged

Storage: Fix slow download performance #5791

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c00cb4c
download blob using direct download method
ajaaym Jul 19, 2019
615dab7
update test case
ajaaym Jul 19, 2019
ae1ffab
fix format
ajaaym Jul 19, 2019
1bdc864
add test case for retries
ajaaym Jul 19, 2019
48777c2
remove method
ajaaym Jul 30, 2019
0aebf4c
update test retry setting
ajaaym Jul 30, 2019
58469f5
fix lint and add comment
ajaaym Jul 31, 2019
cb65519
fix lint
ajaaym Jul 31, 2019
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44 changes: 32 additions & 12 deletions google-cloud-clients/google-cloud-storage/src/main/java/com/google/cloud/storage/Blob.java
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Original file line number Diff line number Diff line change
Expand Up @@ -16,9 +16,11 @@

package com.google.cloud.storage;

import static com.google.cloud.RetryHelper.runWithRetries;
import static com.google.cloud.storage.Blob.BlobSourceOption.toGetOptions;
import static com.google.cloud.storage.Blob.BlobSourceOption.toSourceOptions;
import static com.google.common.base.Preconditions.checkNotNull;
import static java.util.concurrent.Executors.callable;

import com.google.api.services.storage.model.StorageObject;
import com.google.auth.ServiceAccountSigner;
Expand All @@ -34,13 +36,11 @@
import com.google.cloud.storage.spi.v1.StorageRpc;
import com.google.common.base.Function;
import com.google.common.io.BaseEncoding;
import com.google.common.io.CountingOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.OutputStream;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.WritableByteChannel;
import java.nio.file.Files;
import java.nio.file.Path;
import java.security.Key;
Expand Down Expand Up @@ -211,20 +211,40 @@ static Storage.BlobGetOption[] toGetOptions(BlobInfo blobInfo, BlobSourceOption.
* @throws StorageException upon failure
*/
public void downloadTo(Path path, BlobSourceOption... options) {
try (OutputStream outputStream = Files.newOutputStream(path);
ReadChannel reader = reader(options)) {
WritableByteChannel channel = Channels.newChannel(outputStream);
ByteBuffer bytes = ByteBuffer.allocate(DEFAULT_CHUNK_SIZE);
while (reader.read(bytes) > 0) {
bytes.flip();
channel.write(bytes);
bytes.clear();
}
try (OutputStream outputStream = Files.newOutputStream(path)) {
downloadTo(outputStream, options);
} catch (IOException e) {
throw new StorageException(e);
}
}

/**
* Downloads this blob to the given output stream using specified blob read options.
*
* @param outputStream
* @param options
*/
public void downloadTo(OutputStream outputStream, BlobSourceOption... options) {
final CountingOutputStream countingOutputStream = new CountingOutputStream(outputStream);
final StorageRpc storageRpc = this.options.getStorageRpcV1();
final Map<StorageRpc.Option, ?> requestOptions = StorageImpl.optionMap(getBlobId(), options);
runWithRetries(
callable(
new Runnable() {
@Override
public void run() {
storageRpc.read(
getBlobId().toPb(),
requestOptions,
countingOutputStream.getCount(),
countingOutputStream);
}
}),
this.options.getRetrySettings(),
StorageImpl.EXCEPTION_HANDLER,
this.options.getClock());
}

/**
* Downloads this blob to the given file path.
*
Expand Down
101 changes: 85 additions & 16 deletions ...e-cloud-clients/google-cloud-storage/src/test/java/com/google/cloud/storage/BlobTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,9 @@
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertTrue;

import com.google.api.core.ApiClock;
import com.google.api.gax.retrying.RetrySettings;
import com.google.api.services.storage.model.StorageObject;
import com.google.cloud.ReadChannel;
import com.google.cloud.storage.Acl.Project;
import com.google.cloud.storage.Acl.Project.ProjectRole;
Expand All @@ -41,12 +44,13 @@
import com.google.cloud.storage.Blob.BlobSourceOption;
import com.google.cloud.storage.Storage.BlobWriteOption;
import com.google.cloud.storage.Storage.CopyRequest;
import com.google.cloud.storage.spi.v1.StorageRpc;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.io.BaseEncoding;
import java.io.File;
import java.io.OutputStream;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.file.Files;
import java.security.Key;
import java.util.List;
Expand Down Expand Up @@ -131,6 +135,24 @@ public class BlobTest {
private static final Key KEY =
new SecretKeySpec(BaseEncoding.base64().decode(BASE64_KEY), "AES256");

// This retrying setting is used by test testDownloadWithRetries. This unit test is setup
// to write one byte and then throw retryable exception, it then writes another bytes on
// second call succeeds.
private static final RetrySettings RETRY_SETTINGS =
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@frankyn frankyn Jul 25, 2019

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There's heavy retry settings in the tests. Is this by design and how do they help?

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@ajaaym ajaaym Jul 30, 2019

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updated retry settings needed for test.

RetrySettings.newBuilder().setMaxAttempts(2).build();
private static final ApiClock API_CLOCK =
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@frankyn frankyn Jul 30, 2019

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Please document how retries are being exercised in these unit tests. It will help for posterity.

new ApiClock() {
@Override
public long nanoTime() {
return 42_000_000_000L;
}

@Override
public long millisTime() {
return 42_000L;
}
};

private Storage storage;
private Blob blob;
private Blob expectedBlob;
Expand Down Expand Up @@ -566,28 +588,75 @@ public void testBuilder() {
@Test
public void testDownload() throws Exception {
final byte[] expected = {1, 2};
StorageRpc mockStorageRpc = createNiceMock(StorageRpc.class);
expect(storage.getOptions()).andReturn(mockOptions).times(1);
replay(storage);
expect(mockOptions.getStorageRpcV1()).andReturn(mockStorageRpc);
expect(mockOptions.getRetrySettings()).andReturn(RETRY_SETTINGS);
expect(mockOptions.getClock()).andReturn(API_CLOCK);
replay(mockOptions);
blob = new Blob(storage, new BlobInfo.BuilderImpl(BLOB_INFO));
expect(
mockStorageRpc.read(
anyObject(StorageObject.class),
anyObject(Map.class),
eq(0l),
anyObject(OutputStream.class)))
.andAnswer(
new IAnswer<Long>() {
@Override
public Long answer() throws Throwable {
((OutputStream) getCurrentArguments()[3]).write(expected);
return 2l;
}
});
replay(mockStorageRpc);
File file = File.createTempFile("blob", ".tmp");
blob.downloadTo(file.toPath());
byte actual[] = Files.readAllBytes(file.toPath());
assertArrayEquals(expected, actual);
}

initializeExpectedBlob(2);
ReadChannel channel = createNiceMock(ReadChannel.class);
@Test
public void testDownloadWithRetries() throws Exception {
final byte[] expected = {1, 2};
StorageRpc mockStorageRpc = createNiceMock(StorageRpc.class);
expect(storage.getOptions()).andReturn(mockOptions);
expect(storage.reader(BLOB_INFO.getBlobId())).andReturn(channel);
replay(storage);
// First read should return 2 bytes.
expect(channel.read(anyObject(ByteBuffer.class)))
expect(mockOptions.getStorageRpcV1()).andReturn(mockStorageRpc);
expect(mockOptions.getRetrySettings()).andReturn(RETRY_SETTINGS);
expect(mockOptions.getClock()).andReturn(API_CLOCK);
replay(mockOptions);
blob = new Blob(storage, new BlobInfo.BuilderImpl(BLOB_INFO));
expect(
mockStorageRpc.read(
anyObject(StorageObject.class),
anyObject(Map.class),
eq(0l),
anyObject(OutputStream.class)))
.andAnswer(
new IAnswer<Integer>() {
new IAnswer<Long>() {
@Override
public Integer answer() throws Throwable {
// Modify the argument to match the expected behavior of `read`.
((ByteBuffer) getCurrentArguments()[0]).put(expected);
return 2;
public Long answer() throws Throwable {
((OutputStream) getCurrentArguments()[3]).write(expected[0]);
throw new StorageException(504, "error");
}
});
// Second read should return 0 bytes.
expect(channel.read(anyObject(ByteBuffer.class))).andReturn(0);
replay(channel);
initializeBlob();

expect(
mockStorageRpc.read(
anyObject(StorageObject.class),
anyObject(Map.class),
eq(1l),
anyObject(OutputStream.class)))
.andAnswer(
new IAnswer<Long>() {
@Override
public Long answer() throws Throwable {
((OutputStream) getCurrentArguments()[3]).write(expected[1]);
return 1l;
}
});
replay(mockStorageRpc);
File file = File.createTempFile("blob", ".tmp");
blob.downloadTo(file.toPath());
byte actual[] = Files.readAllBytes(file.toPath());
Expand Down