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Posted to commits@flink.apache.org by se...@apache.org on 2019/05/10 23:34:00 UTC
[flink] 01/14: [FLINK-12378][docs] Consolidate FileSystem
Documentation
This is an automated email from the ASF dual-hosted git repository.
sewen pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/flink.git
commit b50896a55288b363fd369368c0823abbe99aa36c
Author: Seth Wiesman <sj...@gmail.com>
AuthorDate: Tue Apr 30 16:45:49 2019 -0500
[FLINK-12378][docs] Consolidate FileSystem Documentation
---
docs/ops/deployment/aws.md | 74 +--------
docs/ops/filesystems.md | 177 ---------------------
docs/ops/filesystems/common.md | 68 ++++++++
docs/ops/filesystems/common.zh.md | 68 ++++++++
docs/ops/filesystems/index.md | 83 ++++++++++
.../{filesystems.zh.md => filesystems/index.zh.md} | 2 +
docs/ops/{deployment => filesystems}/oss.md | 7 +-
docs/ops/{deployment => filesystems}/oss.zh.md | 4 +-
docs/ops/filesystems/s3.md | 134 ++++++++++++++++
docs/ops/filesystems/s3.zh.md | 134 ++++++++++++++++
docs/redirects/filesystems.md | 24 +++
docs/redirects/oss.md | 24 +++
12 files changed, 544 insertions(+), 255 deletions(-)
diff --git a/docs/ops/deployment/aws.md b/docs/ops/deployment/aws.md
index ae43c40..a639e9c 100644
--- a/docs/ops/deployment/aws.md
+++ b/docs/ops/deployment/aws.md
@@ -64,81 +64,11 @@ HADOOP_CONF_DIR=/etc/hadoop/conf ./bin/flink run -m yarn-cluster -yn 1 examples/
{% top %}
-## S3: Simple Storage Service
-
-[Amazon Simple Storage Service](http://aws.amazon.com/s3/) (Amazon S3) provides cloud object storage for a variety of use cases. You can use S3 with Flink for **reading** and **writing data** as well in conjunction with the [streaming **state backends**]({{ site.baseurl}}/ops/state/state_backends.html) or even as a YARN object storage.
-
-You can use S3 objects like regular files by specifying paths in the following format:
-
-{% highlight plain %}
-s3://<your-bucket>/<endpoint>
-{% endhighlight %}
-
-The endpoint can either be a single file or a directory, for example:
-
-{% highlight java %}
-// Read from S3 bucket
-env.readTextFile("s3://<bucket>/<endpoint>");
-
-// Write to S3 bucket
-stream.writeAsText("s3://<bucket>/<endpoint>");
-
-// Use S3 as FsStatebackend
-env.setStateBackend(new FsStateBackend("s3://<your-bucket>/<endpoint>"));
-{% endhighlight %}
-
-Note that these examples are *not* exhaustive and you can use S3 in other places as well, including your [high availability setup](../jobmanager_high_availability.html) or the [RocksDBStateBackend]({{ site.baseurl }}/ops/state/state_backends.html#the-rocksdbstatebackend); everywhere that Flink expects a FileSystem URI.
-
-For most use cases, you may use one of our shaded `flink-s3-fs-hadoop` and `flink-s3-fs-presto` S3
-filesystem wrappers which are fairly easy to set up. For some cases, however, e.g. for using S3 as
-YARN's resource storage dir, it may be necessary to set up a specific Hadoop S3 FileSystem
-implementation. Both ways are described below.
-
-### Shaded Hadoop/Presto S3 file systems (recommended)
-
-{% panel **Note:** You don't have to configure this manually if you are running [Flink on EMR](#emr-elastic-mapreduce). %}
-
-To use either `flink-s3-fs-hadoop` or `flink-s3-fs-presto`, copy the respective JAR file from the
-`opt` directory to the `lib` directory of your Flink distribution before starting Flink, e.g.
-
-{% highlight bash %}
-cp ./opt/flink-s3-fs-presto-{{ site.version }}.jar ./lib/
-{% endhighlight %}
-
-Both `flink-s3-fs-hadoop` and `flink-s3-fs-presto` register default FileSystem
-wrappers for URIs with the `s3://` scheme, `flink-s3-fs-hadoop` also registers
-for `s3a://` and `flink-s3-fs-presto` also registers for `s3p://`, so you can
-use this to use both at the same time.
-
-#### Configure Access Credentials
-
-After setting up the S3 FileSystem wrapper, you need to make sure that Flink is allowed to access your S3 buckets.
-
-##### Identity and Access Management (IAM) (Recommended)
-
-The recommended way of setting up credentials on AWS is via [Identity and Access Management (IAM)](http://docs.aws.amazon.com/IAM/latest/UserGuide/introduction.html). You can use IAM features to securely give Flink instances the credentials that they need in order to access S3 buckets. Details about how to do this are beyond the scope of this documentation. Please refer to the AWS user guide. What you are looking for are [IAM Roles](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam- [...]
-
-If you set this up correctly, you can manage access to S3 within AWS and don't need to distribute any access keys to Flink.
-
-##### Access Keys (Discouraged)
-
-Access to S3 can be granted via your **access and secret key pair**. Please note that this is discouraged since the [introduction of IAM roles](https://blogs.aws.amazon.com/security/post/Tx1XG3FX6VMU6O5/A-safer-way-to-distribute-AWS-credentials-to-EC2).
-
-You need to configure both `s3.access-key` and `s3.secret-key` in Flink's `flink-conf.yaml`:
-
-{% highlight yaml %}
-s3.access-key: your-access-key
-s3.secret-key: your-secret-key
-{% endhighlight %}
-
-{% top %}
-
-### Hadoop-provided S3 file systems - manual setup
+### Hadoop-provided S3 file systems
{% panel **Note:** You don't have to configure this manually if you are running [Flink on EMR](#emr-elastic-mapreduce). %}
-This setup is a bit more complex and we recommend using our shaded Hadoop/Presto file systems
-instead (see above) unless required otherwise, e.g. for using S3 as YARN's resource storage dir
+Apache Flink provides native [S3 FileSystem's](../filesystems/s3.html) out of the box and we recomend using them unless required otherwise, e.g. for using S3 as YARN's resource storage dir
via the `fs.defaultFS` configuration property in Hadoop's `core-site.xml`.
#### Set S3 FileSystem
diff --git a/docs/ops/filesystems.md b/docs/ops/filesystems.md
deleted file mode 100644
index 025255b..0000000
--- a/docs/ops/filesystems.md
+++ /dev/null
@@ -1,177 +0,0 @@
----
-title: "File Systems"
-nav-parent_id: ops
-nav-pos: 12
----
-<!--
-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.
--->
-
-This page provides details on setting up and configuring different file systems for use with Flink.
-We start by describing how to use and configure the different file systems that are supported by Flink
-out-of-the-box, before describing the necessary steps in order to add support about other/custom file system
-implementations.
-
-## Flink's File System support
-
-Flink uses file systems both as *sources* and *sinks* in streaming/batch applications and as a target for *checkpointing*.
-These file systems can for example be *Unix/Windows file systems*, *HDFS*, or even object stores like *S3*.
-
-The file system used for a specific file is determined by the file URI's scheme. For example `file:///home/user/text.txt` refers to
-a file in the local file system, while `hdfs://namenode:50010/data/user/text.txt` refers to a file in a specific HDFS cluster.
-
-File systems are represented via the `org.apache.flink.core.fs.FileSystem` class, which captures the ways to access and modify
-files and objects in that file system. FileSystem instances are instantiated once per process and then cached / pooled, to
-avoid configuration overhead per stream creation and to enforce certain constraints, such as connection/stream limits.
-
-### Built-in File Systems
-
-Flink ships with support for most of the popular file systems, namely *local*, *hadoop-compatible*, *S3*, *MapR FS*
-and *OpenStack Swift FS*. Each of these is identified by the scheme included in the URI of the provide file path.
-
-Flink ships with implementations for the following file systems:
-
- - **local**: This file system is used when the scheme is *"file://"*, and it represents the file system of the local machine,
-including any NFS or SAN that is mounted into that local file system.
-
- - **S3**: Flink directly provides file systems to talk to Amazon S3. There are two alternative implementations, `flink-s3-fs-presto`
- and `flink-s3-fs-hadoop`. Both implementations are self-contained with no dependency footprint. There is no need to add Hadoop to
- the classpath to use them. Both internally use some Hadoop code, but "shade away" all classes to avoid any dependency conflicts.
-
- - `flink-s3-fs-presto`, registered under the scheme *"s3://"* and *"s3p://"*, is based on code from the [Presto project](https://prestodb.io/).
- You can configure it the same way you can [configure the Presto file system](https://prestodb.io/docs/0.187/connector/hive.html#amazon-s3-configuration).
-
- - `flink-s3-fs-hadoop`, registered under *"s3://"* and *"s3a://"*, based on code from the [Hadoop Project](https://hadoop.apache.org/).
- The file system can be [configured exactly like Hadoop's s3a](https://hadoop.apache.org/docs/stable/hadoop-aws/tools/hadoop-aws/index.html#S3A).
-
- To use those file systems when using Flink as a library, add the respective maven dependency (`org.apache.flink:flink-s3-fs-presto:{{ site.version }}`
- or `org.apache.flink:flink-s3-fs-hadoop:{{ site.version }}`). When starting a Flink application from the Flink binaries, copy or move
- the respective jar file from the `opt` folder to the `lib` folder. See also [AWS setup](deployment/aws.html) for additional details.
-
- <span class="label label-danger">Attention</span>: As described above, both Hadoop and Presto "listen" to paths with scheme set to *"s3://"*. This is
- convenient for switching between implementations (Hadoop or Presto), but it can lead to non-determinism when both
- implementations are required. This can happen when, for example, the job uses the [StreamingFileSink]({{ site.baseurl}}/dev/connectors/streamfile_sink.html)
- which only supports Hadoop, but uses Presto for checkpointing. In this case, it is advised to use explicitly *"s3a://"*
- as a scheme for the sink (Hadoop) and *"s3p://"* for checkpointing (Presto).
-
- - **MapR FS**: The MapR file system *"maprfs://"* is automatically available when the MapR libraries are in the classpath.
-
- - **OpenStack Swift FS**: Flink directly provides a file system to talk to the OpenStack Swift file system, registered under the scheme *"swift://"*.
- The implementation `flink-swift-fs-hadoop` is based on the [Hadoop Project](https://hadoop.apache.org/) but is self-contained with no dependency footprint.
- To use it when using Flink as a library, add the respective maven dependency (`org.apache.flink:flink-swift-fs-hadoop:{{ site.version }}`
- When starting a Flink application from the Flink binaries, copy or move the respective jar file from the `opt` folder to the `lib` folder.
-
-#### HDFS and Hadoop File System support
-
-For all schemes where it cannot find a directly supported file system, Flink will try to use Hadoop to instantiate a file system for the respective scheme.
-All Hadoop file systems are automatically available once `flink-runtime` and the Hadoop libraries are in classpath.
-
-That way, Flink seamlessly supports all of Hadoop file systems, and all Hadoop-compatible file systems (HCFS), for example:
-
- - **hdfs**
- - **ftp**
- - **s3n** and **s3a**
- - **har**
- - ...
-
-
-## Common File System configurations
-
-The following configuration settings exist across different file systems.
-
-#### Default File System
-
-If paths to files do not explicitly specify a file system scheme (and authority), a default scheme (and authority) will be used.
-
-{% highlight yaml %}
-fs.default-scheme: <default-fs>
-{% endhighlight %}
-
-For example, if the default file system configured as `fs.default-scheme: hdfs://localhost:9000/`, then a file path of
-`/user/hugo/in.txt` is interpreted as `hdfs://localhost:9000/user/hugo/in.txt`.
-
-#### Connection limiting
-
-You can limit the total number of connections that a file system can concurrently open. This is useful when the file system cannot handle a large number
-of concurrent reads / writes or open connections at the same time.
-
-For example, very small HDFS clusters with few RPC handlers can sometimes be overwhelmed by a large Flink job trying to build up many connections during a checkpoint.
-
-To limit a specific file system's connections, add the following entries to the Flink configuration. The file system to be limited is identified by
-its scheme.
-
-{% highlight yaml %}
-fs.<scheme>.limit.total: (number, 0/-1 mean no limit)
-fs.<scheme>.limit.input: (number, 0/-1 mean no limit)
-fs.<scheme>.limit.output: (number, 0/-1 mean no limit)
-fs.<scheme>.limit.timeout: (milliseconds, 0 means infinite)
-fs.<scheme>.limit.stream-timeout: (milliseconds, 0 means infinite)
-{% endhighlight %}
-
-You can limit the number if input/output connections (streams) separately (`fs.<scheme>.limit.input` and `fs.<scheme>.limit.output`), as well as impose a limit on
-the total number of concurrent streams (`fs.<scheme>.limit.total`). If the file system tries to open more streams, the operation will block until some streams are closed.
-If the opening of the stream takes longer than `fs.<scheme>.limit.timeout`, the stream opening will fail.
-
-To prevent inactive streams from taking up the complete pool (preventing new connections to be opened), you can add an inactivity timeout for streams:
-`fs.<scheme>.limit.stream-timeout`. If a stream does not read/write any bytes for at least that amount of time, it is forcibly closed.
-
-These limits are enforced per TaskManager, so each TaskManager in a Flink application or cluster will open up to that number of connections.
-In addition, the limits are also only enforced per FileSystem instance. Because File Systems are created per scheme and authority, different
-authorities will have their own connection pool. For example `hdfs://myhdfs:50010/` and `hdfs://anotherhdfs:4399/` will have separate pools.
-
-## Entropy injection for S3 file systems
-
-The bundled S3 file systems (`flink-s3-fs-presto` and `flink-s3-fs-hadoop`) support entropy injection. Entropy injection is
-a technique to improve scalability of AWS S3 buckets through adding some random characters near the beginning of the key.
-
-If entropy injection is activated, a configured substring in the paths will be replaced by random characters. For example, path
-`s3://my-bucket/checkpoints/_entropy_/dashboard-job/` would be replaced by something like `s3://my-bucket/checkpoints/gf36ikvg/dashboard-job/`.
-
-**Note that this only happens when the file creation passes the option to inject entropy!**, otherwise the file path will
-simply remove the entropy key substring. See
-[FileSystem.create(Path, WriteOption)](https://ci.apache.org/projects/flink/flink-docs-release-1.6/api/java/org/apache/flink/core/fs/FileSystem.html#create-org.apache.flink.core.fs.Path-org.apache.flink.core.fs.FileSystem.WriteOptions-)
-for details.
-
-*Note: The Flink runtime currently passes the option to inject entropy only to checkpoint data files.*
-*All other files, including checkpoint metadata and external URI do not inject entropy, to keep checkpoint URIs predictable.*
-
-To enable entropy injection, configure the *entropy key* and the *entropy length* parameters.
-
-```
-s3.entropy.key: _entropy_
-s3.entropy.length: 4 (default)
-
-```
-
-The `s3.entropy.key` defines the string in paths that is replaced by the random characters. Paths that do not contain the entropy key are left unchanged.
-If a file system operation does not pass the *"inject entropy"* write option, the entropy key substring is simply removed.
-The `s3.entropy.length` defined the number of random alphanumeric characters to replace the entropy key with.
-
-## Adding new File System Implementations
-
-File system implementations are discovered by Flink through Java's service abstraction, making it easy to add additional file system implementations.
-
-In order to add a new File System, the following steps are needed:
-
- - Add the File System implementation, which is a subclass of `org.apache.flink.core.fs.FileSystem`.
- - Add a factory that instantiates that file system and declares the scheme under which the FileSystem is registered. This must be a subclass of `org.apache.flink.core.fs.FileSystemFactory`.
- - Add a service entry. Create a file `META-INF/services/org.apache.flink.core.fs.FileSystemFactory` which contains the class name of your file system factory class.
-
-See the [Java Service Loader docs](https://docs.oracle.com/javase/8/docs/api/java/util/ServiceLoader.html) for more details on how service loaders work.
-
-{% top %}
diff --git a/docs/ops/filesystems/common.md b/docs/ops/filesystems/common.md
new file mode 100644
index 0000000..edef1dd
--- /dev/null
+++ b/docs/ops/filesystems/common.md
@@ -0,0 +1,68 @@
+---
+title: "Common Configurations"
+nav-parent_id: filesystems
+nav-pos: 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.
+-->
+
+Apache Flink provides a number of common configuration settings that work across all file system implementations.
+
+* This will be replaced by the TOC
+{:toc}
+
+## Default File System
+
+If paths to files do not explicitly specify a file system scheme (and authority), a default scheme (and authority) will be used.
+
+{% highlight yaml %}
+fs.default-scheme: <default-fs>
+{% endhighlight %}
+
+For example, if the default file system configured as `fs.default-scheme: hdfs://localhost:9000/`, then a file path of
+`/user/hugo/in.txt` is interpreted as `hdfs://localhost:9000/user/hugo/in.txt`.
+
+## Connection limiting
+
+You can limit the total number of connections that a file system can concurrently open. This is useful when the file system cannot handle a large number
+of concurrent reads / writes or open connections at the same time.
+
+For example, very small HDFS clusters with few RPC handlers can sometimes be overwhelmed by a large Flink job trying to build up many connections during a checkpoint.
+
+To limit a specific file system's connections, add the following entries to the Flink configuration. The file system to be limited is identified by
+its scheme.
+
+{% highlight yaml %}
+fs.<scheme>.limit.total: (number, 0/-1 mean no limit)
+fs.<scheme>.limit.input: (number, 0/-1 mean no limit)
+fs.<scheme>.limit.output: (number, 0/-1 mean no limit)
+fs.<scheme>.limit.timeout: (milliseconds, 0 means infinite)
+fs.<scheme>.limit.stream-timeout: (milliseconds, 0 means infinite)
+{% endhighlight %}
+
+You can limit the number if input/output connections (streams) separately (`fs.<scheme>.limit.input` and `fs.<scheme>.limit.output`), as well as impose a limit on
+the total number of concurrent streams (`fs.<scheme>.limit.total`). If the file system tries to open more streams, the operation will block until some streams are closed.
+If the opening of the stream takes longer than `fs.<scheme>.limit.timeout`, the stream opening will fail.
+
+To prevent inactive streams from taking up the complete pool (preventing new connections to be opened), you can add an inactivity timeout for streams:
+`fs.<scheme>.limit.stream-timeout`. If a stream does not read/write any bytes for at least that amount of time, it is forcibly closed.
+
+These limits are enforced per TaskManager, so each TaskManager in a Flink application or cluster will open up to that number of connections.
+In addition, the limits are also only enforced per FileSystem instance. Because File Systems are created per scheme and authority, different
+authorities will have their own connection pool. For example `hdfs://myhdfs:50010/` and `hdfs://anotherhdfs:4399/` will have separate pools.
\ No newline at end of file
diff --git a/docs/ops/filesystems/common.zh.md b/docs/ops/filesystems/common.zh.md
new file mode 100644
index 0000000..edef1dd
--- /dev/null
+++ b/docs/ops/filesystems/common.zh.md
@@ -0,0 +1,68 @@
+---
+title: "Common Configurations"
+nav-parent_id: filesystems
+nav-pos: 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.
+-->
+
+Apache Flink provides a number of common configuration settings that work across all file system implementations.
+
+* This will be replaced by the TOC
+{:toc}
+
+## Default File System
+
+If paths to files do not explicitly specify a file system scheme (and authority), a default scheme (and authority) will be used.
+
+{% highlight yaml %}
+fs.default-scheme: <default-fs>
+{% endhighlight %}
+
+For example, if the default file system configured as `fs.default-scheme: hdfs://localhost:9000/`, then a file path of
+`/user/hugo/in.txt` is interpreted as `hdfs://localhost:9000/user/hugo/in.txt`.
+
+## Connection limiting
+
+You can limit the total number of connections that a file system can concurrently open. This is useful when the file system cannot handle a large number
+of concurrent reads / writes or open connections at the same time.
+
+For example, very small HDFS clusters with few RPC handlers can sometimes be overwhelmed by a large Flink job trying to build up many connections during a checkpoint.
+
+To limit a specific file system's connections, add the following entries to the Flink configuration. The file system to be limited is identified by
+its scheme.
+
+{% highlight yaml %}
+fs.<scheme>.limit.total: (number, 0/-1 mean no limit)
+fs.<scheme>.limit.input: (number, 0/-1 mean no limit)
+fs.<scheme>.limit.output: (number, 0/-1 mean no limit)
+fs.<scheme>.limit.timeout: (milliseconds, 0 means infinite)
+fs.<scheme>.limit.stream-timeout: (milliseconds, 0 means infinite)
+{% endhighlight %}
+
+You can limit the number if input/output connections (streams) separately (`fs.<scheme>.limit.input` and `fs.<scheme>.limit.output`), as well as impose a limit on
+the total number of concurrent streams (`fs.<scheme>.limit.total`). If the file system tries to open more streams, the operation will block until some streams are closed.
+If the opening of the stream takes longer than `fs.<scheme>.limit.timeout`, the stream opening will fail.
+
+To prevent inactive streams from taking up the complete pool (preventing new connections to be opened), you can add an inactivity timeout for streams:
+`fs.<scheme>.limit.stream-timeout`. If a stream does not read/write any bytes for at least that amount of time, it is forcibly closed.
+
+These limits are enforced per TaskManager, so each TaskManager in a Flink application or cluster will open up to that number of connections.
+In addition, the limits are also only enforced per FileSystem instance. Because File Systems are created per scheme and authority, different
+authorities will have their own connection pool. For example `hdfs://myhdfs:50010/` and `hdfs://anotherhdfs:4399/` will have separate pools.
\ No newline at end of file
diff --git a/docs/ops/filesystems/index.md b/docs/ops/filesystems/index.md
new file mode 100644
index 0000000..be8bbee
--- /dev/null
+++ b/docs/ops/filesystems/index.md
@@ -0,0 +1,83 @@
+---
+title: "File Systems"
+nav-id: filesystems
+nav-parent_id: ops
+nav-show_overview: true
+nav-pos: 12
+---
+<!--
+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.
+-->
+
+Apache Flink uses file system for both ingest and output of data for streaming and batch applications as well as targets for checkpoint storage.
+These file systems can be local such as *Unix*, distributed like *HDFS*, or even object stores such as *S3*.
+
+The file system used for a particular file is determined by its URI scheme.
+For example, `file:///home/user/text.txt` refers to a file in the local file system, while `hdfs://namenode:50010/data/user/text.txt` is a file in a specific HDFS cluster.
+
+FileSystem instances are instantiated once per process and then cached / pooled, to
+avoid configuration overhead per stream creation and to enforce certain constraints, such as connection/stream limits.
+
+* This will be replaced by the TOC
+{:toc}
+
+### Built-in File Systems
+
+Flink ships with support for most of the popular file systems, including *local*, *hadoop-compatible*, *S3*, *MapR FS* and *OpenStack Swift FS*.
+Each is identified by the scheme included in the URI of the provide file path.
+
+Flink ships with implementations for the following file systems:
+
+ - **local**: This file system is used when the scheme is *"file://"*, and it represents the file system of the local machine, including any NFS or SAN that is mounted into that local file system.
+
+ - **S3**: Flink directly provides file systems to talk to Amazon S3 with two alternative implementations, `flink-s3-fs-presto` and `flink-s3-fs-hadoop`. Both implementations are self-contained with no dependency footprint.
+
+ - **MapR FS**: The MapR file system *"maprfs://"* is automatically available when the MapR libraries are in the classpath.
+
+ - **OpenStack Swift FS**: Flink directly provides a file system to talk to the OpenStack Swift file system, registered under the scheme *"swift://"*.
+ The implementation `flink-swift-fs-hadoop` is based on the [Hadoop Project](https://hadoop.apache.org/) but is self-contained with no dependency footprint.
+ To use it when using Flink as a library, add the respective maven dependency (`org.apache.flink:flink-swift-fs-hadoop:{{ site.version }}`
+ When starting a Flink application from the Flink binaries, copy or move the respective jar file from the `opt` folder to the `lib` folder.
+
+#### HDFS and Hadoop File System support
+
+For all schemes where Flink cannot find a directly supported file system, it will fall back to Hadoop.
+All Hadoop file systems are automatically available when `flink-runtime` and the Hadoop libraries are in classpath.
+
+This way, Flink seamlessly supports all of Hadoop file systems, and all Hadoop-compatible file systems (HCFS).
+
+ - **hdfs**
+ - **ftp**
+ - **s3n** and **s3a**
+ - **har**
+ - ...
+
+## Adding new File System Implementations
+
+File systems are represented via the `org.apache.flink.core.fs.FileSystem` class, which captures the ways to access and modify files and objects in that file system.
+Implementations are discovered by Flink through Java's service abstraction, making it easy to add additional file system implementations.
+
+In order to add a new File System, the following steps are needed:
+
+ - Add the File System implementation, which is a subclass of `org.apache.flink.core.fs.FileSystem`.
+ - Add a factory that instantiates that file system and declares the scheme under which the FileSystem is registered. This must be a subclass of `org.apache.flink.core.fs.FileSystemFactory`.
+ - Add a service entry. Create a file `META-INF/services/org.apache.flink.core.fs.FileSystemFactory` which contains the class name of your file system factory class.
+
+See the [Java Service Loader docs](https://docs.oracle.com/javase/8/docs/api/java/util/ServiceLoader.html) for more details on how service loaders work.
+
+{% top %}
diff --git a/docs/ops/filesystems.zh.md b/docs/ops/filesystems/index.zh.md
similarity index 99%
rename from docs/ops/filesystems.zh.md
rename to docs/ops/filesystems/index.zh.md
index 4df02cc..9390239 100644
--- a/docs/ops/filesystems.zh.md
+++ b/docs/ops/filesystems/index.zh.md
@@ -1,6 +1,8 @@
---
title: "文件系统"
+nav-id: filesystems
nav-parent_id: ops
+nav-show_overview: true
nav-pos: 12
---
<!--
diff --git a/docs/ops/deployment/oss.md b/docs/ops/filesystems/oss.md
similarity index 99%
rename from docs/ops/deployment/oss.md
rename to docs/ops/filesystems/oss.md
index b706767..8711e6f 100644
--- a/docs/ops/deployment/oss.md
+++ b/docs/ops/filesystems/oss.md
@@ -1,8 +1,8 @@
---
title: "Aliyun Object Storage Service (OSS)"
nav-title: Aliyun OSS
-nav-parent_id: deployment
-nav-pos: 9
+nav-parent_id: filesystems
+nav-pos: 2
---
<!--
Licensed to the Apache Software Foundation (ASF) under one
@@ -23,10 +23,9 @@ specific language governing permissions and limitations
under the License.
-->
-* ToC
+* This will be replaced by the TOC
{:toc}
-
## OSS: Object Storage Service
[Aliyun Object Storage Service](https://www.aliyun.com/product/oss) (Aliyun OSS) is widely used especially among China’s cloud users, and it provides cloud object storage for a variety of use cases.
diff --git a/docs/ops/deployment/oss.zh.md b/docs/ops/filesystems/oss.zh.md
similarity index 99%
rename from docs/ops/deployment/oss.zh.md
rename to docs/ops/filesystems/oss.zh.md
index 356510e..fa2dfb1 100644
--- a/docs/ops/deployment/oss.zh.md
+++ b/docs/ops/filesystems/oss.zh.md
@@ -1,8 +1,8 @@
---
title: "Aliyun 对象存储服务 (OSS)"
nav-title: Aliyun OSS
-nav-parent_id: deployment
-nav-pos: 9
+nav-parent_id: filesystems
+nav-pos: 2
---
<!--
Licensed to the Apache Software Foundation (ASF) under one
diff --git a/docs/ops/filesystems/s3.md b/docs/ops/filesystems/s3.md
new file mode 100644
index 0000000..9ae1476
--- /dev/null
+++ b/docs/ops/filesystems/s3.md
@@ -0,0 +1,134 @@
+---
+title: "Amazon S3"
+nav-title: Amazon S3
+nav-parent_id: filesystems
+nav-pos: 1
+---
+<!--
+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.
+-->
+
+[Amazon Simple Storage Service](http://aws.amazon.com/s3/) (Amazon S3) provides cloud object storage for a variety of use cases. You can use S3 with Flink for **reading** and **writing data** as well in conjunction with the [streaming **state backends**]({{ site.baseurl}}/ops/state/state_backends.html).
+
+* This will be replaced by the TOC
+{:toc}
+
+You can use S3 objects like regular files by specifying paths in the following format:
+
+{% highlight plain %}
+s3://<your-bucket>/<endpoint>
+{% endhighlight %}
+
+The endpoint can either be a single file or a directory, for example:
+
+{% highlight java %}
+// Read from S3 bucket
+env.readTextFile("s3://<bucket>/<endpoint>");
+
+// Write to S3 bucket
+stream.writeAsText("s3://<bucket>/<endpoint>");
+
+// Use S3 as FsStatebackend
+env.setStateBackend(new FsStateBackend("s3://<your-bucket>/<endpoint>"));
+{% endhighlight %}
+
+Note that these examples are *not* exhaustive and you can use S3 in other places as well, including your [high availability setup](../jobmanager_high_availability.html) or the [RocksDBStateBackend]({{ site.baseurl }}/ops/state/state_backends.html#the-rocksdbstatebackend); everywhere that Flink expects a FileSystem URI.
+
+For most use cases, you may use one of our shaded `flink-s3-fs-hadoop` and `flink-s3-fs-presto` S3
+filesystem wrappers which are fairly easy to set up. For some cases, however, e.g. for using S3 as
+YARN's resource storage dir, it may be necessary to set up a specific Hadoop S3 FileSystem
+implementation. Both ways are described below.
+
+### Shaded Hadoop/Presto S3 file systems
+
+{% panel **Note:** You don't have to configure this manually if you are running [Flink on EMR](../deployment/aws.html). %}
+
+Flink provides two file systems to talk to Amazon S3, `flink-s3-fs-presto` and `flink-s3-fs-hadoop`.
+Both implementations are self-contained with no dependency footprint.
+There is no need to add Hadoop to the classpath to use them.
+Both internally use some Hadoop code, but "shade away" all classes to avoid any dependency conflicts.
+
+ - `flink-s3-fs-presto`, registered under the scheme *"s3://"* and *"s3p://"*, is based on code from the [Presto project](https://prestodb.io/).
+ You can configure it the same way you can [configure the Presto file system](https://prestodb.io/docs/0.187/connector/hive.html#amazon-s3-configuration).
+
+ - `flink-s3-fs-hadoop`, registered under *"s3://"* and *"s3a://"*, based on code from the [Hadoop Project](https://hadoop.apache.org/).
+ The file system can be [configured exactly like Hadoop's s3a](https://hadoop.apache.org/docs/stable/hadoop-aws/tools/hadoop-aws/index.html#S3A).
+
+Both `flink-s3-fs-hadoop` and `flink-s3-fs-presto` register default FileSystem
+wrappers for URIs with the `s3://` scheme, `flink-s3-fs-hadoop` also registers
+for `s3a://` and `flink-s3-fs-presto` also registers for `s3p://`, so you can
+use this to use both at the same time.
+This can happen when, for example, the job uses the [StreamingFileSink]({{ site.baseurl}}/dev/connectors/streamfile_sink.html) which only supports Hadoop, but uses Presto for checkpointing.
+In this case, it is advised to use explicitly *"s3a://"* as a scheme for the sink (Hadoop) and *"s3p://"* for checkpointing (Presto).
+
+To use either `flink-s3-fs-hadoop` or `flink-s3-fs-presto`, copy the respective JAR file from the `opt` directory to the `lib` directory of your Flink distribution before starting Flink, e.g.
+
+{% highlight bash %}
+cp ./opt/flink-s3-fs-presto-{{ site.version }}.jar ./lib/
+{% endhighlight %}
+
+#### Configure Access Credentials
+
+After setting up the S3 FileSystem wrapper, you need to make sure that Flink is allowed to access your S3 buckets.
+
+##### Identity and Access Management (IAM) (Recommended)
+
+The recommended way of setting up credentials on AWS is via [Identity and Access Management (IAM)](http://docs.aws.amazon.com/IAM/latest/UserGuide/introduction.html). You can use IAM features to securely give Flink instances the credentials that they need in order to access S3 buckets. Details about how to do this are beyond the scope of this documentation. Please refer to the AWS user guide. What you are looking for are [IAM Roles](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam- [...]
+
+If you set this up correctly, you can manage access to S3 within AWS and don't need to distribute any access keys to Flink.
+
+##### Access Keys (Discouraged)
+
+Access to S3 can be granted via your **access and secret key pair**. Please note that this is discouraged since the [introduction of IAM roles](https://blogs.aws.amazon.com/security/post/Tx1XG3FX6VMU6O5/A-safer-way-to-distribute-AWS-credentials-to-EC2).
+
+You need to configure both `s3.access-key` and `s3.secret-key` in Flink's `flink-conf.yaml`:
+
+{% highlight yaml %}
+s3.access-key: your-access-key
+s3.secret-key: your-secret-key
+{% endhighlight %}
+
+{% top %}
+
+## Entropy injection for S3 file systems
+
+The bundled S3 file systems (`flink-s3-fs-presto` and `flink-s3-fs-hadoop`) support entropy injection. Entropy injection is
+a technique to improve scalability of AWS S3 buckets through adding some random characters near the beginning of the key.
+
+If entropy injection is activated, a configured substring in the paths will be replaced by random characters. For example, path
+`s3://my-bucket/checkpoints/_entropy_/dashboard-job/` would be replaced by something like `s3://my-bucket/checkpoints/gf36ikvg/dashboard-job/`.
+
+**Note that this only happens when the file creation passes the option to inject entropy!**, otherwise the file path will
+simply remove the entropy key substring. See
+[FileSystem.create(Path, WriteOption)](https://ci.apache.org/projects/flink/flink-docs-release-1.6/api/java/org/apache/flink/core/fs/FileSystem.html#create-org.apache.flink.core.fs.Path-org.apache.flink.core.fs.FileSystem.WriteOptions-)
+for details.
+
+*Note: The Flink runtime currently passes the option to inject entropy only to checkpoint data files.*
+*All other files, including checkpoint metadata and external URI do not inject entropy, to keep checkpoint URIs predictable.*
+
+To enable entropy injection, configure the *entropy key* and the *entropy length* parameters.
+
+```
+s3.entropy.key: _entropy_
+s3.entropy.length: 4 (default)
+
+```
+
+The `s3.entropy.key` defines the string in paths that is replaced by the random characters. Paths that do not contain the entropy key are left unchanged.
+If a file system operation does not pass the *"inject entropy"* write option, the entropy key substring is simply removed.
+The `s3.entropy.length` defined the number of random alphanumeric characters to replace the entropy key with.
\ No newline at end of file
diff --git a/docs/ops/filesystems/s3.zh.md b/docs/ops/filesystems/s3.zh.md
new file mode 100644
index 0000000..9ae1476
--- /dev/null
+++ b/docs/ops/filesystems/s3.zh.md
@@ -0,0 +1,134 @@
+---
+title: "Amazon S3"
+nav-title: Amazon S3
+nav-parent_id: filesystems
+nav-pos: 1
+---
+<!--
+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.
+-->
+
+[Amazon Simple Storage Service](http://aws.amazon.com/s3/) (Amazon S3) provides cloud object storage for a variety of use cases. You can use S3 with Flink for **reading** and **writing data** as well in conjunction with the [streaming **state backends**]({{ site.baseurl}}/ops/state/state_backends.html).
+
+* This will be replaced by the TOC
+{:toc}
+
+You can use S3 objects like regular files by specifying paths in the following format:
+
+{% highlight plain %}
+s3://<your-bucket>/<endpoint>
+{% endhighlight %}
+
+The endpoint can either be a single file or a directory, for example:
+
+{% highlight java %}
+// Read from S3 bucket
+env.readTextFile("s3://<bucket>/<endpoint>");
+
+// Write to S3 bucket
+stream.writeAsText("s3://<bucket>/<endpoint>");
+
+// Use S3 as FsStatebackend
+env.setStateBackend(new FsStateBackend("s3://<your-bucket>/<endpoint>"));
+{% endhighlight %}
+
+Note that these examples are *not* exhaustive and you can use S3 in other places as well, including your [high availability setup](../jobmanager_high_availability.html) or the [RocksDBStateBackend]({{ site.baseurl }}/ops/state/state_backends.html#the-rocksdbstatebackend); everywhere that Flink expects a FileSystem URI.
+
+For most use cases, you may use one of our shaded `flink-s3-fs-hadoop` and `flink-s3-fs-presto` S3
+filesystem wrappers which are fairly easy to set up. For some cases, however, e.g. for using S3 as
+YARN's resource storage dir, it may be necessary to set up a specific Hadoop S3 FileSystem
+implementation. Both ways are described below.
+
+### Shaded Hadoop/Presto S3 file systems
+
+{% panel **Note:** You don't have to configure this manually if you are running [Flink on EMR](../deployment/aws.html). %}
+
+Flink provides two file systems to talk to Amazon S3, `flink-s3-fs-presto` and `flink-s3-fs-hadoop`.
+Both implementations are self-contained with no dependency footprint.
+There is no need to add Hadoop to the classpath to use them.
+Both internally use some Hadoop code, but "shade away" all classes to avoid any dependency conflicts.
+
+ - `flink-s3-fs-presto`, registered under the scheme *"s3://"* and *"s3p://"*, is based on code from the [Presto project](https://prestodb.io/).
+ You can configure it the same way you can [configure the Presto file system](https://prestodb.io/docs/0.187/connector/hive.html#amazon-s3-configuration).
+
+ - `flink-s3-fs-hadoop`, registered under *"s3://"* and *"s3a://"*, based on code from the [Hadoop Project](https://hadoop.apache.org/).
+ The file system can be [configured exactly like Hadoop's s3a](https://hadoop.apache.org/docs/stable/hadoop-aws/tools/hadoop-aws/index.html#S3A).
+
+Both `flink-s3-fs-hadoop` and `flink-s3-fs-presto` register default FileSystem
+wrappers for URIs with the `s3://` scheme, `flink-s3-fs-hadoop` also registers
+for `s3a://` and `flink-s3-fs-presto` also registers for `s3p://`, so you can
+use this to use both at the same time.
+This can happen when, for example, the job uses the [StreamingFileSink]({{ site.baseurl}}/dev/connectors/streamfile_sink.html) which only supports Hadoop, but uses Presto for checkpointing.
+In this case, it is advised to use explicitly *"s3a://"* as a scheme for the sink (Hadoop) and *"s3p://"* for checkpointing (Presto).
+
+To use either `flink-s3-fs-hadoop` or `flink-s3-fs-presto`, copy the respective JAR file from the `opt` directory to the `lib` directory of your Flink distribution before starting Flink, e.g.
+
+{% highlight bash %}
+cp ./opt/flink-s3-fs-presto-{{ site.version }}.jar ./lib/
+{% endhighlight %}
+
+#### Configure Access Credentials
+
+After setting up the S3 FileSystem wrapper, you need to make sure that Flink is allowed to access your S3 buckets.
+
+##### Identity and Access Management (IAM) (Recommended)
+
+The recommended way of setting up credentials on AWS is via [Identity and Access Management (IAM)](http://docs.aws.amazon.com/IAM/latest/UserGuide/introduction.html). You can use IAM features to securely give Flink instances the credentials that they need in order to access S3 buckets. Details about how to do this are beyond the scope of this documentation. Please refer to the AWS user guide. What you are looking for are [IAM Roles](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam- [...]
+
+If you set this up correctly, you can manage access to S3 within AWS and don't need to distribute any access keys to Flink.
+
+##### Access Keys (Discouraged)
+
+Access to S3 can be granted via your **access and secret key pair**. Please note that this is discouraged since the [introduction of IAM roles](https://blogs.aws.amazon.com/security/post/Tx1XG3FX6VMU6O5/A-safer-way-to-distribute-AWS-credentials-to-EC2).
+
+You need to configure both `s3.access-key` and `s3.secret-key` in Flink's `flink-conf.yaml`:
+
+{% highlight yaml %}
+s3.access-key: your-access-key
+s3.secret-key: your-secret-key
+{% endhighlight %}
+
+{% top %}
+
+## Entropy injection for S3 file systems
+
+The bundled S3 file systems (`flink-s3-fs-presto` and `flink-s3-fs-hadoop`) support entropy injection. Entropy injection is
+a technique to improve scalability of AWS S3 buckets through adding some random characters near the beginning of the key.
+
+If entropy injection is activated, a configured substring in the paths will be replaced by random characters. For example, path
+`s3://my-bucket/checkpoints/_entropy_/dashboard-job/` would be replaced by something like `s3://my-bucket/checkpoints/gf36ikvg/dashboard-job/`.
+
+**Note that this only happens when the file creation passes the option to inject entropy!**, otherwise the file path will
+simply remove the entropy key substring. See
+[FileSystem.create(Path, WriteOption)](https://ci.apache.org/projects/flink/flink-docs-release-1.6/api/java/org/apache/flink/core/fs/FileSystem.html#create-org.apache.flink.core.fs.Path-org.apache.flink.core.fs.FileSystem.WriteOptions-)
+for details.
+
+*Note: The Flink runtime currently passes the option to inject entropy only to checkpoint data files.*
+*All other files, including checkpoint metadata and external URI do not inject entropy, to keep checkpoint URIs predictable.*
+
+To enable entropy injection, configure the *entropy key* and the *entropy length* parameters.
+
+```
+s3.entropy.key: _entropy_
+s3.entropy.length: 4 (default)
+
+```
+
+The `s3.entropy.key` defines the string in paths that is replaced by the random characters. Paths that do not contain the entropy key are left unchanged.
+If a file system operation does not pass the *"inject entropy"* write option, the entropy key substring is simply removed.
+The `s3.entropy.length` defined the number of random alphanumeric characters to replace the entropy key with.
\ No newline at end of file
diff --git a/docs/redirects/filesystems.md b/docs/redirects/filesystems.md
new file mode 100644
index 0000000..4aad652
--- /dev/null
+++ b/docs/redirects/filesystems.md
@@ -0,0 +1,24 @@
+---
+title: "File Systems"
+layout: redirect
+redirect: /ops/filesystems.html
+permalink: /ops/filesystems/index.html
+---
+<!--
+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.
+-->
\ No newline at end of file
diff --git a/docs/redirects/oss.md b/docs/redirects/oss.md
new file mode 100644
index 0000000..3b34502
--- /dev/null
+++ b/docs/redirects/oss.md
@@ -0,0 +1,24 @@
+---
+title: "Aliyun Object Storage Service (OSS)"
+layout: redirect
+redirect: /ops/deployment/oss.html
+permalink: /ops/filesystems/oss.html
+---
+<!--
+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.
+-->
\ No newline at end of file