HADOOP-14248. Retire SharedInstanceProfileCredentialsProvider in trunk. Contributed by Mingliang Liu.

This commit is contained in:
Chris Nauroth 2017-04-12 10:02:13 -07:00
parent a16ab2be91
commit b8305e6d06
5 changed files with 13 additions and 108 deletions

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@ -955,13 +955,8 @@
configuration of AWS access key ID and secret access key in
environment variables named AWS_ACCESS_KEY_ID and
AWS_SECRET_ACCESS_KEY, as documented in the AWS SDK.
3. org.apache.hadoop.fs.s3a.SharedInstanceProfileCredentialsProvider:
a shared instance of
com.amazonaws.auth.InstanceProfileCredentialsProvider from the AWS
SDK, which supports use of instance profile credentials if running
in an EC2 VM. Using this shared instance potentially reduces load
on the EC2 instance metadata service for multi-threaded
applications.
3. com.amazonaws.auth.InstanceProfileCredentialsProvider: supports use
of instance profile credentials if running in an EC2 VM.
</description>
</property>

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@ -339,15 +339,9 @@ public final class S3AUtils {
credentials.add(new BasicAWSCredentialsProvider(
creds.getUser(), creds.getPassword()));
credentials.add(new EnvironmentVariableCredentialsProvider());
credentials.add(
SharedInstanceProfileCredentialsProvider.getInstance());
credentials.add(InstanceProfileCredentialsProvider.getInstance());
} else {
for (Class<?> aClass : awsClasses) {
if (aClass == InstanceProfileCredentialsProvider.class) {
LOG.debug("Found {}, but will use {} instead.", aClass.getName(),
SharedInstanceProfileCredentialsProvider.class.getName());
aClass = SharedInstanceProfileCredentialsProvider.class;
}
credentials.add(createAWSCredentialProvider(conf, aClass));
}
}

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@ -1,67 +0,0 @@
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.fs.s3a;
import com.amazonaws.auth.InstanceProfileCredentialsProvider;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* A subclass of {@link InstanceProfileCredentialsProvider} that enforces
* instantiation of only a single instance.
* This credential provider calls the EC2 instance metadata service to obtain
* credentials. For highly multi-threaded applications, it's possible that
* multiple instances call the service simultaneously and overwhelm it with
* load. The service handles this by throttling the client with an HTTP 429
* response or forcibly terminating the connection. Forcing use of a single
* instance reduces load on the metadata service by allowing all threads to
* share the credentials. The base class is thread-safe, and there is nothing
* that varies in the credentials across different instances of
* {@link S3AFileSystem} connecting to different buckets, so sharing a singleton
* instance is safe.
*
* As of AWS SDK 1.11.39, the SDK code internally enforces a singleton. After
* Hadoop upgrades to that version or higher, it's likely that we can remove
* this class.
*/
@InterfaceAudience.Private
@InterfaceStability.Stable
public final class SharedInstanceProfileCredentialsProvider
extends InstanceProfileCredentialsProvider {
private static final SharedInstanceProfileCredentialsProvider INSTANCE =
new SharedInstanceProfileCredentialsProvider();
/**
* Returns the singleton instance.
*
* @return singleton instance
*/
public static SharedInstanceProfileCredentialsProvider getInstance() {
return INSTANCE;
}
/**
* Default constructor, defined explicitly as private to enforce singleton.
*/
private SharedInstanceProfileCredentialsProvider() {
super();
}
}

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@ -328,13 +328,8 @@ of `com.amazonaws.auth.AWSCredentialsProvider` may also be used.
configuration of AWS access key ID and secret access key in
environment variables named AWS_ACCESS_KEY_ID and
AWS_SECRET_ACCESS_KEY, as documented in the AWS SDK.
3. org.apache.hadoop.fs.s3a.SharedInstanceProfileCredentialsProvider:
a shared instance of
com.amazonaws.auth.InstanceProfileCredentialsProvider from the AWS
SDK, which supports use of instance profile credentials if running
in an EC2 VM. Using this shared instance potentially reduces load
on the EC2 instance metadata service for multi-threaded
applications.
3. com.amazonaws.auth.InstanceProfileCredentialsProvider: supports use
of instance profile credentials if running in an EC2 VM.
</description>
</property>
@ -407,13 +402,12 @@ AWS Credential Providers are classes which can be used by the Amazon AWS SDK to
obtain an AWS login from a different source in the system, including environment
variables, JVM properties and configuration files.
There are four AWS Credential Providers inside the `hadoop-aws` JAR:
There are three AWS Credential Providers inside the `hadoop-aws` JAR:
| classname | description |
|-----------|-------------|
| `org.apache.hadoop.fs.s3a.TemporaryAWSCredentialsProvider`| Session Credentials |
| `org.apache.hadoop.fs.s3a.SimpleAWSCredentialsProvider`| Simple name/secret credentials |
| `org.apache.hadoop.fs.s3a.SharedInstanceProfileCredentialsProvider`| Shared instance of EC2 Metadata Credentials, which can reduce load on the EC2 instance metadata service. (See below.) |
| `org.apache.hadoop.fs.s3a.AnonymousAWSCredentialsProvider`| Anonymous Login |
There are also many in the Amazon SDKs, in particular two which are automatically
@ -425,24 +419,13 @@ set up in the authentication chain:
| `com.amazonaws.auth.EnvironmentVariableCredentialsProvider`| AWS Environment Variables |
*EC2 Metadata Credentials with `SharedInstanceProfileCredentialsProvider`*
*EC2 Metadata Credentials with `InstanceProfileCredentialsProvider`*
Applications running in EC2 may associate an IAM role with the VM and query the
[EC2 Instance Metadata Service](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html)
for credentials to access S3. Within the AWS SDK, this functionality is
provided by `InstanceProfileCredentialsProvider`. Heavily multi-threaded
applications may trigger a high volume of calls to the instance metadata service
and trigger throttling: either an HTTP 429 response or a forcible close of the
connection.
To mitigate against this problem, `hadoop-aws` ships with a variant of
`InstanceProfileCredentialsProvider` called
`SharedInstanceProfileCredentialsProvider`. Using this ensures that all
instances of S3A reuse the same instance profile credentials instead of issuing
a large volume of redundant metadata service calls. If
`fs.s3a.aws.credentials.provider` refers to
`com.amazonaws.auth.InstanceProfileCredentialsProvider`, S3A automatically uses
`org.apache.hadoop.fs.s3a.SharedInstanceProfileCredentialsProvider` instead.
provided by `InstanceProfileCredentialsProvider`, which internally enforces a
singleton instance in order to prevent throttling problem.
*Session Credentials with `TemporaryAWSCredentialsProvider`*
@ -542,7 +525,7 @@ This means that the default S3A authentication chain can be defined as
<value>
org.apache.hadoop.fs.s3a.SimpleAWSCredentialsProvider,
com.amazonaws.auth.EnvironmentVariableCredentialsProvider,
org.apache.hadoop.fs.s3a.SharedInstanceProfileCredentialsProvider
com.amazonaws.auth.InstanceProfileCredentialsProvider
</value>
</property>
@ -929,7 +912,7 @@ role information available when deployed in Amazon EC2.
```xml
<property>
<name>fs.s3a.aws.credentials.provider</name>
<value>org.apache.hadoop.fs.s3a.SharedInstanceProfileCredentialsProvider</value>
<value>com.amazonaws.auth.InstanceProfileCredentialsProvider</value>
</property>
```

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@ -114,7 +114,7 @@ public class TestS3AAWSCredentialsProvider {
Arrays.asList(
BasicAWSCredentialsProvider.class,
EnvironmentVariableCredentialsProvider.class,
SharedInstanceProfileCredentialsProvider.class);
InstanceProfileCredentialsProvider.class);
assertCredentialProviders(expectedClasses, list1);
assertCredentialProviders(expectedClasses, list2);
assertSameInstanceProfileCredentialsProvider(list1.getProviders().get(2),
@ -128,7 +128,7 @@ public class TestS3AAWSCredentialsProvider {
List<Class<? extends AWSCredentialsProvider>> expectedClasses =
Arrays.asList(
EnvironmentVariableCredentialsProvider.class,
SharedInstanceProfileCredentialsProvider.class,
InstanceProfileCredentialsProvider.class,
AnonymousAWSCredentialsProvider.class);
conf.set(AWS_CREDENTIALS_PROVIDER, buildClassListString(expectedClasses));
AWSCredentialProviderList list1 = S3AUtils.createAWSCredentialProviderSet(