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This module contains code to support integration with Amazon Web Services.
It also declares the dependencies needed to work with AWS services.
/*
* 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.impl;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import org.apache.hadoop.thirdparty.com.google.common.annotations.VisibleForTesting;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.fs.s3a.Constants;
/**
* Internal constants private only to the S3A codebase.
* Please don't refer to these outside of this module & its tests.
* If you find you need to then either the code is doing something it
* should not, or these constants need to be uprated to being
* public and stable entries.
*/
public final class InternalConstants {
/**
* This declared delete as idempotent.
* This is an "interesting" topic in past Hadoop FS work.
* Essentially: with a single caller, DELETE is idempotent
* but in a shared filesystem, it is is very much not so.
* Here, on the basis that isn't a filesystem with consistency guarantees,
* retryable results in files being deleted.
*/
public static final boolean DELETE_CONSIDERED_IDEMPOTENT = true;
private InternalConstants() {
}
/**
* This is an arbitrary value: {@value}.
* It declares how many parallel copy operations
* in a single rename can be queued before the operation pauses
* and awaits completion.
* A very large value wouldn't just starve other threads from
* performing work, there's a risk that the S3 store itself would
* throttle operations (which all go to the same shard).
* It is not currently configurable just to avoid people choosing values
* which work on a microbenchmark (single rename, no other work, ...)
* but don't scale well to execution in a large process against a common
* store, all while separate processes are working with the same shard
* of storage.
*
* It should be a factor of {@link #MAX_ENTRIES_TO_DELETE} so that
* all copies will have finished before deletion is contemplated.
* (There's always a block for that, it just makes more sense to
* perform the bulk delete after another block of copies have completed).
*/
public static final int RENAME_PARALLEL_LIMIT = 10;
/**
* The maximum number of entries that can be deleted in any bulk delete
* call to S3: {@value}.
*/
public static final int MAX_ENTRIES_TO_DELETE = 1000;
/**
* Default blocksize as used in blocksize and FS status queries: {@value}.
*/
public static final int DEFAULT_BLOCKSIZE = 32 * 1024 * 1024;
/**
* The known keys used in a standard openFile call.
* if there's a select marker in there then the keyset
* used becomes that of the select operation.
*/
@InterfaceStability.Unstable
public static final Set STANDARD_OPENFILE_KEYS =
Collections.unmodifiableSet(
new HashSet<>(
Arrays.asList(Constants.INPUT_FADVISE,
Constants.READAHEAD_RANGE)));
/** 403 error code. */
public static final int SC_403 = 403;
/** 404 error code. */
public static final int SC_404 = 404;
/** Name of the log for throttling events. Value: {@value}. */
public static final String THROTTLE_LOG_NAME =
"org.apache.hadoop.fs.s3a.throttled";
/** Directory marker attribute: see HADOOP-16613. Value: {@value}. */
public static final String X_DIRECTORY =
"application/x-directory";
/**
* A configuration option for test use only: maximum
* part count on block writes/uploads.
* Value: {@value}.
*/
@VisibleForTesting
public static final String UPLOAD_PART_COUNT_LIMIT =
"fs.s3a.internal.upload.part.count.limit";
/**
* Maximum entries you can upload in a single file write/copy/upload.
* Value: {@value}.
*/
public static final int DEFAULT_UPLOAD_PART_COUNT_LIMIT = 10000;
/**
* The system property used by the AWS SDK to identify the region.
*/
public static final String AWS_REGION_SYSPROP = "aws.region";
/**
* S3 client side encryption adds padding to the content length of constant
* length of 16 bytes (at the moment, since we have only 1 content
* encryption algorithm). Use this to subtract while listing the content
* length when certain conditions are met.
*/
public static final int CSE_PADDING_LENGTH = 16;
/**
* Error message to indicate S3-CSE is incompatible with S3Guard.
*/
public static final String CSE_S3GUARD_INCOMPATIBLE = "S3-CSE cannot be "
+ "used with S3Guard";
/**
* Error message to indicate Access Points are incompatible with S3Guard.
*/
public static final String AP_S3GUARD_INCOMPATIBLE = "Access Points cannot be used with S3Guard";
/**
* Error message to indicate Access Points are required to be used for S3 access.
*/
public static final String AP_REQUIRED_EXCEPTION = "Access Points usage is required" +
" but not configured for the bucket.";
/**
* Error message to indicate Access Points are not accessible or don't exist.
*/
public static final String AP_INACCESSIBLE = "Could not access through this access point";
/**
* AccessPoint ARN for the bucket. When set as a bucket override the requests for that bucket
* will go through the AccessPoint.
*/
public static final String ARN_BUCKET_OPTION = "fs.s3a.bucket.%s.accesspoint.arn";
}