Add new s3 sink documentation for Data Prepper 2.8

_data-prepper/pipelines/configuration/sinks/s3.md

@@ -15,19 +15,20 @@
 ```
 ${pathPrefix}events-%{yyyy-MM-dd'T'HH-mm-ss'Z'}-${currentTimeInNanos}-${uniquenessId}.${codecSuppliedExtension}
 ```
+{% include copy-curl.html %}
 
-When a batch of objects is written to S3, the objects are formatted similarly to the following:
+When a batch of objects is written to Amazon S3, the objects are formatted similarly to the following:
 
 ```
 my-logs/2023/06/09/06/events-2023-06-09T06-00-01-1686290401871214927-ae15b8fa-512a-59c2-b917-295a0eff97c8.json
 ```
+{% include copy-curl.html %}
 
-
-For more information about how to configure an object, see the [Object key](#object-key-configuration) section.
+For more information about how to configure an object, refer to [Object key](#object-key-configuration).
 
 ## Usage
 
-The following example creates a pipeline configured with an s3 sink. It contains additional options for customizing the event and size thresholds for which the pipeline sends record events and sets the codec type `ndjson`:
+The following example creates a pipeline configured with an `s3` sink. It contains additional options for customizing the event and size thresholds for the pipeline and sets the codec type as `ndjson`:
 
 ```
 pipeline:
@@ -49,10 +50,11 @@
           ndjson:
         buffer_type: in_memory
 ```
+{% include copy-curl.html %}
 
 ## IAM permissions
 
-In order to use the `s3` sink, configure AWS Identity and Access Management (IAM) to grant Data Prepper permissions to write to Amazon S3. You can use a configuration similar to the following JSON configuration:
+To use the `s3` sink, configure AWS Identity and Access Management (IAM) to grant Data Prepper permissions to write to Amazon S3. You can use a configuration similar to the following JSON configuration:
 
 ```json
 {
@@ -69,121 +71,140 @@
     ]
 }
 ```
+{% include copy-curl.html %}
+
+## Cross-account S3 access<a name="s3_bucket_ownership"></a>
+
+When Data Prepper fetches data from an S3 bucket, it verifies bucket ownership using a [bucket owner condition](https://docs.aws.amazon.com/AmazonS3/latest/userguide/bucket-owner-condition.html). 
+
+By default, the S3 sink does not require `bucket_owners`. If `bucket_owners` is configured and a bucket is not included in one of the mapped configurations, `default_bucket_owner` defaults to the account ID in `aws.sts_role_arn`. You can configure both `bucket_owners` and `default_bucket_owner` and apply the settings together.
+
+When ingesting data from multiple S3 buckets with different account associations, configure Data Prepper for cross-account S3 access based on the following conditions:
+
+- For S3 buckets belonging to the same account, set `default_bucket_owner` to that account's ID.
+- For S3 buckets belonging to multiple accounts, use a `bucket_owners` map.
+
+A `bucket_owners` map specifies account IDs for buckets belonging to multiple accounts. For example, in the following configuration, `my-bucket-01` is owned by `123456789012` and `my-bucket-02` is owned by `999999999999`:
+
+```
+sink:
+  - s3:
+      default_bucket_owner: 111111111111
+      bucket_owners:
+        my-bucket-01: 123456789012
+        my-bucket-02: 999999999999
+```
+{% include copy-curl.html %}
 
 ## Configuration 
 
 Use the following options when customizing the `s3` sink.
 
-Option | Required | Type | Description
-:--- | :--- | :--- | :---
-`bucket` | Yes | String | The name of the S3 bucket to which objects are stored. The `name` must match the name of your object store.
-`codec` | Yes | [Codec](#codec) | The codec determining the format of output data.
-`aws` | Yes | AWS | The AWS configuration. See [aws](#aws) for more information.
-`threshold` | Yes | [Threshold](#threshold-configuration) | Configures when to write an object to S3. 
-`object_key` | No | Sets the `path_prefix` and the `file_pattern` of the object store. The file pattern is always `events-%{yyyy-MM-dd'T'hh-mm-ss}`. By default, those objects are found inside the root directory of the bucket. The `path_prefix` is configurable.
-`compression` | No | String | The compression algorithm to apply: `none`, `gzip`, or `snappy`. Default is `none`. 
-`buffer_type` | No | [Buffer type](#buffer-type) | Determines the buffer type. 
-`max_retries` | No | Integer | The maximum number of times a single request should retry when ingesting data to S3. Defaults to `5`.
-
-## aws
+Option | Required | Type                                            | Description
+:--- |:---------|:------------------------------------------------| :---
+`bucket` | Yes      | String                                          | Specifies the sink's S3 bucket name. Supports dynamic bucket naming using [Data Prepper expressions]({{site.url}}{{site.baseurl}}/data-prepper/pipelines/expression-syntax/), for example, `test-${/bucket_id}`. If a dynamic bucket is inaccessible and no `default_bucket` is configured, then the object data is dropped.
+`default_bucket` | No       | String                                          | A static bucket for inaccessible dynamic buckets in `bucket`. 
+`bucket_owners` | No       | Map                                             | A map of bucket names and their account owner IDs for cross-account access. Refer to [Cross-account S3 access](#s3_bucket_ownership). 
+`default_bucket_owner` | No       | String                                          | The AWS account ID for an S3 bucket owner. Refer to [Cross-account S3 access](#s3_bucket_ownership). 
+`codec` | Yes      | [Codec](#codec)                                 | Serializes data in S3 objects.
+`aws` | Yes      | AWS                                             | The AWS configuration. Refer to [aws](#aws).
+`threshold` | Yes      | [Threshold](#threshold-configuration)           | Condition for writing objects to S3. 
+`aggregate_threshold` | No       | [Aggregate threshold](#threshold-configuration) | A condition for flushing objects with a dynamic `path_prefix`. 
+`object_key` | No       | [Object key](#object-key-configuration)         | Sets `path_prefix` and `file_pattern` for object storage. The file pattern is `events-%{yyyy-MM-dd'T'hh-mm-ss}`. By default, these objects are found in the bucket's root directory. `path_prefix` is configurable.
+`compression` | No       | String                                          | The compression algorithm: Either `none`, `gzip`, or `snappy`. Default is `none`. 
+`buffer_type` | No       | [Buffer type](#buffer-type)                     | The buffer type configuration. 
+`max_retries` | No       | Integer                                         | The maximum number of retries for S3 ingestion requests. Default is `5`.
+
+## `aws`
 
 Option | Required | Type | Description
 :--- | :--- | :--- | :---
 `region` | No | String | The AWS Region to use for credentials. Defaults to [standard SDK behavior to determine the Region](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/region-selection.html).
-`sts_role_arn` | No | String | The AWS Security Token Service (AWS STS) role to assume for requests to Amazon SQS and Amazon S3. Defaults to `null`, which will use the [standard SDK behavior for credentials](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/credentials.html).
+`sts_role_arn` | No | String | The AWS Security Token Service (AWS STS) role to assume for requests to Amazon Simple Queue Service (Amazon SQS) and Amazon S3. Defaults to `null`, which uses [standard SDK behavior for credentials](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/credentials.html).
 `sts_header_overrides` | No | Map | A map of header overrides that the IAM role assumes for the sink plugin.
-`sts_external_id` | No | String | An STS external ID used when Data Prepper assumes the role. For more information, see the `ExternalId` documentation in the [STS AssumeRole](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html) API reference.
-
-
+`sts_external_id` | No | String | An AWS STS external ID used when Data Prepper assumes the role. For more information, refer to the `ExternalId` section under [AssumeRole](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html) in the AWS STS API reference.
 
 ## Threshold configuration
 
-Use the following options to set ingestion thresholds for the `s3` sink. When any of these conditions are met, Data Prepper will write events to an S3 object.
+Use the following options to set ingestion thresholds for the `s3` sink. Data Prepper writes events to an S3 object when any of these conditions occur.
 
 Option | Required | Type | Description
 :--- | :--- | :--- | :---
 `event_count` | Yes | Integer | The number of Data Prepper events to accumulate before writing an object to S3.
 `maximum_size` | No | String | The maximum number of bytes to accumulate before writing an object to S3. Default is `50mb`.
-`event_collect_timeout` | Yes | String | The maximum amount of time before Data Prepper writes an event to S3. The value should be either an ISO-8601 duration, such as `PT2M30S`, or a simple notation, such as `60s` or `1500ms`.
+`event_collect_timeout` | Yes | String | The maximum amount of timeout before Data Prepper writes an event to S3. The value should be either an ISO-8601 duration, such as `PT2M30S`, or a simple notation, such as `60s` or `1500ms`.
+
+## Aggregate threshold configuration
+
+Use the following options to set rules or limits that trigger certain actions or behavior when an aggregated value crosses a defined threshold.
 
+Option | Required                           | Type   | Description
+:--- |:-----------------------------------|:-------| :---
+`flush_capacity_ratio` | No                                 | Float  | The percentage of groups to be force-flushed when `aggregate_threshold maximum_size` is reached. Percentage is expressed from `0.0`--`1.0`. Default is `0.5`.
+`maximum_size` | Yes  | String | The maximum number of bytes to accumulate before force-flushing objects. For example, `128mb`.
 
 ## Buffer type
 
-`buffer_type` is an optional configuration that determines how Data Prepper temporarily stores data before writing an object to S3. The default value is `in_memory`. Use one of the following options:
+`buffer_type` is an optional configuration that determines how Data Prepper temporarily stores data before writing an object to S3. The default value is `in_memory`. 
+
+Use one of the following options:
 
 - `in_memory`: Stores the record in memory.
-- `local_file`: Flushes the record into a file on your local machine. This uses your machine's temporary directory.
+- `local_file`: Flushes the record into a file on your local machine. This option uses your machine's temporary directory.
 - `multipart`: Writes using the [S3 multipart upload](https://docs.aws.amazon.com/AmazonS3/latest/userguide/mpuoverview.html). Every 10 MB is written as a part.
 
 ## Object key configuration
 
+Use the following options to define how object keys are constructed for objects stored in S3.
+
 Option | Required | Type | Description
 :--- | :--- | :--- | :---
-`path_prefix` | No | String | The S3 key prefix path to use for objects written to S3. Accepts date-time formatting. For example, you can use `%{yyyy}/%{MM}/%{dd}/%{HH}/` to create hourly folders in S3. The prefix path should end with `/`. By default, Data Prepper writes objects to the root of the S3 bucket.
-
+`path_prefix` | No | String | The S3 key prefix path to use for objects written to S3. Accepts date-time formatting and dynamic injection of values using [Data Prepper expressions](https://opensearch.org/docs/latest/data-prepper/pipelines/expression-syntax/). For example, you can use `/${/my_partition_key}/%{yyyy}/%{MM}/%{dd}/%{HH}/` to create hourly folders in S3 based on the `my_partition_key` value. The prefix path should end with `/`. By default, Data Prepper writes objects to the S3 bucket root.
 
-## codec
+## `codec`
 
 The `codec` determines how the `s3` source formats data written to each S3 object.
 
-### avro codec
+### `avro` codec
 
-The `avro` codec writes an event as an [Apache Avro](https://avro.apache.org/) document.
+The `avro` codec writes an event as an [Apache Avro](https://avro.apache.org/) document. Because Avro requires a schema, you may either define the schema or have Data Prepper automatically generate it. Defining your own schema is recommended, as this will allow it to be tailored to your particular use case.
 
-Because Avro requires a schema, you may either define the schema yourself, or Data Prepper will automatically generate a schema.
-In general, you should define your own schema because it will most accurately reflect your needs.
+When you provide your own Avro schema, that schema defines the final structure of your data. Any extra values inside any incoming events that are not mapped in the Arvo schema will not be included in the final destination. Data Prepper does not allow the use of the `include_keys` or `exclude_keys` with a custom schema. This is to avoid confusion between a custom Arvo schema and the `include_keys` or `exclude_keys` sink configurations. 
 
-We recommend that you make your Avro fields use a null [union](https://avro.apache.org/docs/current/specification/#unions).
-Without the null union, each field must be present or the data will fail to write to the sink.
-If you can be certain that each each event has a given field, you can make it non-nullable.
+In cases where your data is uniform, you may be able to automatically generate a schema. Auto-generated schemas are based on the first event that the codec receives. The schema will only contain keys from this event, and you must have all keys present in all events in order for the auto-generated schema to produce a working schema. Auto-generated schemas make all fields nullable. Use the `include_keys` and `exclude_keys` sink configurations to control what data is included in the auto-generated schema.
 
-When you provide your own Avro schema, that schema defines the final structure of your data.
-Therefore, any extra values inside any incoming events that are not mapped in the Arvo schema will not be included in the final destination.
-To avoid confusion between a custom Arvo schema and the `include_keys` or `exclude_keys` sink configurations, Data Prepper does not allow the use of the `include_keys` or `exclude_keys` with a custom schema.
-
-In cases where your data is uniform, you may be able to automatically generate a schema.
-Automatically generated schemas are based on the first event received by the codec.
-The schema will only contain keys from this event.
-Therefore, you must have all keys present in all events in order for the automatically generated schema to produce a working schema.
-Automatically generated schemas make all fields nullable.
-Use the sink's `include_keys` and `exclude_keys` configurations to control what data is included in the auto-generated schema.
+Avro fields should use a null [union](https://avro.apache.org/docs/current/specification/#unions), as this will allow missing values. Otherwise, all required fields must be present for each event. Use non-nullable fields only when you are certain they exist.
 
+Use the following options to configure the codec.
 
 Option | Required | Type | Description
 :--- | :--- | :--- | :---
 `schema` | Yes | String | The Avro [schema declaration](https://avro.apache.org/docs/current/specification/#schema-declaration). Not required if `auto_schema` is set to true.
 `auto_schema` | No | Boolean | When set to `true`, automatically generates the Avro [schema declaration](https://avro.apache.org/docs/current/specification/#schema-declaration) from the first event.
-
 
-### ndjson codec
-
-The `ndjson` codec writes each line as a JSON object.
+### `ndjson` codec
 
-The `ndjson` codec does not take any configurations.
+The `ndjson` codec writes each line as a JSON object. The `ndjson` codec does not take any configurations.
 
+### `json` codec
 
-### json codec
-
-The `json` codec writes events in a single large JSON file.
-Each event is written into an object within a JSON array.
+The `json` codec writes events in a single large JSON file. Each event is written into an object within a JSON array.
 
+Use the following options to configure the codec.
 
 Option | Required | Type | Description
 :--- | :--- | :--- | :---
 `key_name` | No | String | The name of the key for the JSON array. By default this is `events`.
 
+### `parquet` codec
 
-### parquet codec
-
-The `parquet` codec writes events into a Parquet file.
-When using the Parquet codec, set the `buffer_type` to `in_memory`.
+The `parquet` codec writes events into a Parquet file. When using the codec, set `buffer_type` to `in_memory`.
 
-The Parquet codec writes data using the Avro schema.
-Because Parquet requires an Avro schema, you may either define the schema yourself, or Data Prepper will automatically generate a schema.
-However, we generally recommend that you define your own schema so that it can best meet your needs.
+The `parquet` codec writes data using the schema. Because Parquet requires an Avro schema, you may either define the schema yourself or have Data Prepper automatically generate it. Defining your own schema is recommended, as this will allow it to be tailored to your particular use case.
 
-For details on the Avro schema and recommendations, see the  [Avro codec](#avro-codec) documentation.
+For details on the Avro schema and recommendations, refer to [Avro codec](#avro-codec).
 
+Use the following options to configure the codec.
 
 Option | Required | Type | Description
 :--- | :--- | :--- | :---
@@ -192,7 +213,7 @@
 
 ### Setting a schema with Parquet
 
-The following example shows you how to configure the `s3` sink to write Parquet data into a Parquet file using a schema for [VPC Flow Logs](https://docs.aws.amazon.com/vpc/latest/userguide/flow-logs.html#flow-log-records):
+The following example pipeline shows how to configure the `s3` sink to write Parquet data into a Parquet file using a schema for [VPC Flow Logs](https://docs.aws.amazon.com/vpc/latest/userguide/flow-logs.html#flow-log-records):
 
 ```
 pipeline:
@@ -235,4 +256,4 @@
           event_collect_timeout: PT15M
         buffer_type: in_memory
 ```
-
+{% include copy-curl.html %}