General

Q: What is Amazon Transfer Family?

A: Amazon Transfer Family offers fully managed support for the transfer of files over SFTP, AS2, FTPS, and FTP directly into and out of Amazon S3 or Amazon EFS. You can seamlessly migrate, automate, and monitor your file transfer workflows by maintaining existing client-side configurations for authentication, access, and firewalls — so nothing changes for your customers, partners, and internal teams, or their applications.

Q: What is SFTP?

A: SFTP stands for Secure Shell (SSH) File Transfer Protocol, a network protocol used for secure transfer of data over the internet. The protocol supports the full security and authentication functionality of SSH, and is widely used to exchange data between business partners in a variety of industries including financial services, healthcare, media and entertainment, retail, advertising, and more.

Q: What is FTP?

A: FTP stands for File Transfer Protocol, a network protocol used for the transfer of data. FTP uses a separate channel for control and data transfers. The control channel is open until terminated or inactivity timeout, the data channel is active for the duration of the transfer. FTP uses cleartext and does not support encryption of traffic.

Q: What is FTPS?

A: FTPS stands for File Transfer Protocol over SSL, and is an extension to FTP. It uses Transport Layer Security (TLS) and Secure Sockets Layer (SSL) cryptographic protocols to encrypt traffic. FTPS allows encryption of both the control and data channel connections either concurrently or independently.

Q: Why should I use the Amazon Transfer Family?

A: Today, if you are using file transfer protocols such as SFTP, FTPS or FTP to exchange data with third parties such as vendors, business partners, or customers, and want to manage that data in for processing, analytics, and archival, you have to host and manage your own file transfer service. This requires you to invest in operating and managing infrastructure, patching servers, monitoring for uptime and availability, and building one-off mechanisms to provision users and audit their activity. The Amazon Transfer Family solves these challenges by providing fully managed support for SFTP, FTPS, and FTP that can reduce your operational burden, while preserving your existing transfer workflows for your end users. The service stores transferred data as objects in your Amazon S3 bucket or as files in your Amazon EFS file system, so you can extract value from them in your data lake, or for your Customer Relationship Management (CRM) or Enterprise Resource Planning (ERP) workflows, or for archiving in.

Q: What are the benefits of using the Amazon Transfer Family?

A: The Amazon Transfer Family provides you with a fully managed, highly available file transfer service with auto-scaling capabilities, eliminating the need for you to manage file transfer related infrastructure. Your end users’ workflows remain unchanged, while data uploaded and downloaded over the chosen protocols is stored in your Amazon S3 bucket or Amazon EFS file system. With the data in Amazon Web Services, you can now easily use it with the broad array of Amazon Web Services services for data processing, content management, analytics, machine learning, and archival, in an environment that can meet your compliance requirements.

Q: How do I use the Amazon Transfer Family for SFTP, FTPS, or FTP?

A: In 3 simple steps, you get an always-on server endpoint enabled for SFTP, FTPS, and/or FTP. First, you select the protocol(s) you want to enable your end users to connect to your endpoint. Next, you set up your users using the service’s built-in authentication (service managed) or by integrating an existing identity provider like Microsoft Active Directory or LDAP (“BYO” authentication). Finally, you choose if you are using the server to access S3 buckets or EFS file systems. Once the protocol(s), identity provider, and the access to file systems are enabled, your users can continue to use their existing SFTP, FTPS, or FTP clients and configurations, while the data accessed is stored in the chosen file systems.

Q: How do I get started with Amazon Transfer Family for AS2?

A: You can start using AS2 to exchange messages with your trading partners in three simple steps: First, import your certificates and private keys and your trading partners’ certificate and certificate chain. Next, create profiles using yours and your partner’s AS2 IDs. Finally, pair up your own and your partner’s profile information using an agreement for receiving data and connector for sending data. At this point you are ready to exchange messages with your trading partner’s AS2 server.

Q: What is the difference between SFTP and FTPS? Which should I use when?

A: FTPS and SFTP can both be used for secure transfers. Since they are different protocols, they use different clients and technologies to offer a secure tunnel for transmission of commands and data. SFTP is a newer protocol and uses a single channel for commands and data, requiring fewer port openings than FTPS.

Q: What is the difference between the SFTP, FTPS, and AS2 protocols? When should I use the AS2 protocol?

A: SFTP, FTPS, and AS2 can all be used for secure transfers. Since they are different protocols, they use different clients and technologies to offer secure transmission of data. Aside from support for encrypted and signed messages, AS2’s built in mechanism for Message Disposition Notification (MDN) alerts the sender that the message has been successfully received and decrypted by the recipient. This provides proof to the sender that their message was delivered without being tampered in transit. Use of AS2 is prevalent in workflows operating in retail, e-commerce, payments, supply chain for interacting with business partners who are also able to use AS2 to transact messages so that it is securely transmitted and delivered. AS2 provides you with options to ensure identity of the sender and receiver, integrity of the message, and confirm whether the message was successfully delivered and decrypted by the receiver.

Q: Can my users continue to use their existing file transfer clients and applications?

A: Yes, any existing file transfer client application will continue to work as long as you have enabled your endpoint for the chosen protocols. Examples of commonly used clients include WinSCP, FileZilla, CyberDuck, lftp, and OpenSSH clients.

Q: Can I use CloudFormation to automate deployment of my servers and users?

A: Yes, you can deploy CloudFormation templates to automate creation of your servers and users or for integrating an identity provider. Refer to the usage guide for using Transfer resources in CloudFormation templates.

Q: Can my users use SCP, HTTPS, or AS2 to transfer files using this service?

A: No, your users will need to use SFTP, FTPS, or FTP to transfer files. Most file transfer clients offer either of these protocols as an option that will need to be selected during authentication. Please let us know via Support or through your account team of any specific protocols you would like to see supported.

Server endpoint options

Q: Can I use my corporate domain name (sftp.mycompanyname.com) to access my endpoint?

A: Yes. If you already have a domain name, you can use Amazon Route 53 or any DNS service to route your users’ traffic from your registered domain to the server endpoint in. Refer to the documentation on how the Amazon Transfer Family uses Amazon Route 53 for custom domain names (applicable to internet facing endpoints only).

Q: Can I still use the service if I don’t have a domain name?

A: Yes, if you don’t have a domain name, your users can access your endpoint using the hostname provided by the service. Alternatively, you can register a new domain using the Amazon Route 53 console or API, and route traffic from this domain to the service supplied endpoint hostname.

Q: Can I use my domain that already has a public zone?

A: Yes, you will need to CNAME the domain to the service supplied endpoint hostname.

Q: Can I set up my server to be accessible to resources only within my VPC?

A: Yes. When you create a server or update an existing one, you have the option to specify whether you want the endpoint to be accessible over the public internet or hosted within your VPC. By using a VPC hosted endpoint for your server, you can restrict it to be accessible only to clients within the same VPC, other VPCs you specify, or in on-premises environments using networking technologies that extend your VPC such as Direct Connect, VPN, or VPC peering. You can further restrict access to resources in specific subnets within your VPC using subnet Network Access Control Lists (NACLs) or Security Groups. Refer to the documentation on creating your server endpoint inside your VPC using PrivateLink for details.

Q: Can I use FTP with an internet facing endpoint?

No, when you enable FTP, you will only be able to use VPC hosted endpoint‘s internal access option. If traffic needs to traverse the public network, secure protocols such as SFTP or FTPS should be used.

Q: What if I need to use FTP for transfers over the public internet?

The service doesn’t allow you to use FTP over public networks because, when you create a server enabled for FTP, the server endpoint is only accessible to resources within your VPC. If you need to use FTP for exchanging data over the public internet, you can front your server’s VPC endpoint with an internet-facing Network Load Balancer (NLB).

Q: Can I use FTP without a VPC?

No. VPC is required to host FTP server endpoints. Please refer to the documentation for CloudFormation templates to automate creation of VPC resources to host the endpoint during server creation.

Q: Can my end users use fixed IP addresses to allow list access to my server’s endpoint in their firewalls?

A: Yes. You can enable fixed IPs for your server endpoint by selecting the VPC hosted endpoint for your server and choosing the internet-facing option. This will allow you to attach Elastic IPs (including BYO IPs) directly to the endpoint, which is assigned as the endpoint’s IP address. Refer to the section on creating an internet facing endpoint in the documentation: Creating your server endpoint inside your VPC.

Q: Can I restrict incoming traffic by end users’ source IP addresses?

A: Yes. You can attach Security Groups to your server’s VPC endpoint which will control inbound traffic to your server. If you are using API Gateway to integrate your identity management system, you can also use WAF to allow, block, or rate limit access by your end users’ Source IP address.

Q: Can I host my server’s endpoint in a shared VPC environment?

A: Yes. You can deploy your server endpoint with shared VPC environments typically used when segmenting your environment using tools such as Landing Zone for security, cost monitoring, and scalability. 

Q: Can I select which cryptographic algorithms can be used when my end users’ clients connect to my server endpoint?

A: Yes, can select one of three security policies to control the cryptographic algorithms that will be advertised by your server endpoints: Transfer-Security-Policy-2018-11 (default), Transfer-Security-Policy-2020-06 (restrictive – No SHA-1 algorithms), and Transfer-FIPS-2020-06 (FIPS compliant algorithms). When your end users’ file transfer clients attempt to connect to your server, only the algorithms specified in the policy will be used to negotiate the connection. Refer to the documentation on pre-defined security policies.

Q: Can my end users use fixed IP addresses to access my server whose endpoint type is PUBLIC?

A: No. Fixed IP addresses that are usually used for firewall whitelisting purposes are currently not supported on the PUBLIC Endpoint type. Use VPC hosted endpoints to assign static IP addresses for your endpoint.

Q: What IP ranges would my end users need to allow list to access my SFTP server’s endpoint type that is PUBLIC?

A: If you are using the PUBLIC endpoint type, your users will need to allow list the IP address ranges. Refer to the documentation for details on staying up to date with IP Address Ranges.

Q: Will my Amazon Transfer for SFTP server's host key ever change after I create the server?

A: No. The server’s host key that is assigned when you create the server remains the same, unless you add a new host key and manually delete the original.

Q: What types of SFTP server host keys are supported?

A: RSA, ED25519, and ECDSA key types are supported for SFTP server host keys.

Q: Can I import keys from my current SFTP server so my users do not have to verify the authenticity of my server again?

A: Yes. You can import a host key when creating a server or import multiple host keys when updating a server. Refer to the documentation on managing host keys for your SFTP-enabled server.

Q: How many host keys can I associate with an SFTP server?

A: You can associate up to 10 host keys per SFTP server. However, only one host key per key type can be used by your end users’ clients to verify the authenticity of your SFTP server in a single session.

Q: How can I identify my multiple host keys?

A: Multiple host keys can be identified using descriptions and tags, which can be added or edited when creating or updating a host key. Each host key also has a unique host key ID as well as an Amazon Resource Name (ARN) that can be used to identify and track the host key.

Q: Can multiple host keys be used to verify the authenticity of my SFTP server?

A: Yes. The oldest host key of each key type can be used to verify the authenticity of an SFTP server. By adding RSA, ED25519, and ECDSA host keys, 3 separate host keys can be used to identify your SFTP server.

Q: Which host keys are used to verify authenticity of my SFTP server?

A: The oldest host key of each key type is used to verify authenticity of your SFTP server.

Q: Can I rotate my SFTP server host keys to ensure secure connections?
A: Yes. You can rotate your SFTP server host keys at any time by adding and removing host keys. Refer to the documentation on managing host keys for your SFTP-enabled server.

Q: How do my end users’ FTPS clients verify the identity of my FTPS server?

A: When you enable FTPS access, you will need to supply a certificate from Amazon Certificate Manager (ACM). This certificate is used by your end user clients to verify the identity of your FTPS server. Refer to the ACM documentation on Requesting New certificates or importing existing certificates into ACM.

Q: Do you support active and passive modes of FTPS and FTP?

A: We only support passive mode, which allows your end users’ clients to initiate connections with your server. Passive mode requires fewer port openings on the client side, making your server endpoint more compatible with end users behind protected firewalls.

Q: Do you support Explicit and Implicit FTPS modes?

A: We only support explicit FTPS mode.

Multi-protocol access

Q: Can I enable multiple protocols on the same endpoint?

A: Yes. During setup, you can select the protocol(s) you want to enable for clients to connect to your endpoint. The server hostname, IP address, and identity provider are shared across the selected protocols. Similarly, you can also enable additional protocol support to existing Amazon Transfer Family endpoints, as long as the endpoint configuration meets the requirements for all the protocols you intend to use.

Q: When should I create separate server endpoints for each protocol vs enable the same endpoint for multiple protocols?

A: When you need to use FTP (only supported for access within VPC), and also need to support over the internet for SFTP, AS2, or FTPS, you will need a separate server endpoint for FTP. You can use the same endpoint for multiple protocols, when you want to use the same endpoint hostname and IP address for clients connecting over multiple protocols. Additionally, if you want to share the same credentials for SFTP and FTPS, you can set up and use a single identity provider for authenticating clients connecting over either protocol.

Q: Can I set up the same end user to access the endpoint over multiple protocols?

Yes, you can provide the same user access over multiple protocols, as long as the credentials specific to the protocol have been set up in your identity provider. If you have enabled FTP, we recommend maintaining separate credentials for FTP. Refer to the documentation for setting up separate credentials for FTP.

Q: Why should I maintain separate credentials for FTP users?

Unlike SFTP and FTPS, FTP transmits credentials in cleartext. We recommend isolating FTP credentials from SFTP or FTPS because, if, inadvertently FTP credentials are shared or exposed, your workloads using SFTP or FTPS remain secure.

Identity Provider options

Q: How does the service authenticate users?

A: The service supports two modes of authentication: Service Managed, where you store user identities within the service, and, Custom (BYO), which enables you to integrate an identity provider of your choice. Service Managed authentication is supported for server endpoints that are enabled for SFTP only.

Q: How can I authenticate my users using Service Managed authentication?

A: You can use Service Managed authentication to authenticate your SFTP users using SSH keys.

Q: How many SSH keys can I upload per SFTP user? Which key types are supported?

A: You can upload up to 10 SSH keys per user. RSA, ED25519, and ECDSA keys are supported.

Q: Is SSH key rotation supported for service managed authentication?

A: Yes. Refer to the documentation for details on how to set up key rotation for your SFTP users.

Q: Can I use the service managed authentication for password authentication?

A: No, storing passwords within the service for authentication is currently not supported.

Q: How do I get started with using Microsoft AD?

A: When you create your server, you select a directory in Amazon Managed Microsoft AD, your on-premises environment, or self-managed AD in Amazon EC2 as your identity provider. You will then need to specify the AD Groups you want to enable for access using a Security Identifier (SID). Once you associate your AD group with access control information such as IAM Role, scope down policy (S3 only), POSIX Profile (EFS only), home directory location, and logical directory mappings, members of the group can use their AD credentials to authenticate and transfer files over the enabled protocols (SFTP, FTPS, FTP).

Q: How can I set up my AD users so they have isolated access to different parts of my S3 bucket?

A: When you set up your users, you supply a scope down policy that is evaluated in run time based on your users’ information such as their username. You can use the same scope down policy for all your users to provide access to unique prefixes in your bucket based on their username. Additionally, a username can also be used to evaluate logical directory mappings by providing a standardized template on how your S3 bucket or EFS file system contents are made visible to your user. Visit the documentation to Grant Access to AD Groups.

Q: Can I use Microsoft AD as an identity provider option for all the supported protocols?

A: Yes, you can use Microsoft AD to authenticate users for access over SFTP, FTPS, and FTP.

Q: Can I revoke access for enabled AD groups?

A: Yes, you can revoke file transfer access for individual AD Groups. Once revoked, members of the AD groups will not be able to transfer files using their AD credentials.

Q: Can I provide access to individual AD users or to all users in a directory?

A: No, we only support setting access by AD Groups.

Q: Can I use AD to authenticate users using SSH keys?

A: No, Amazon Transfer Family support for Microsoft AD can only be used for password-based authentication. To use a mix of authentication modes, use the Custom authorizer option.

Q: Why should I use the Custom authentication mode?

A: The Custom authentication mode (“BYO” authentication) enables you to leverage an existing identity provider to manage your end users for all protocol types (SFTP, FTPS, and FTP), enabling easy and seamless migration of your users. Credentials can be stored in your corporate directory or an in-house identity datastore, and you can integrate it for end user authentication purposes. Examples of identity providers include Microsoft Azure AD, or any custom identity provider that you may be using as a part of an overall provisioning portal.

Q: What options do I have to integrate my identity provider with an Amazon Transfer Family server?

A: To integrate your identity provider with an Amazon Transfer Family server, you can use an Amazon Lambda function, or an Amazon API Gateway endpoint. Use Amazon API Gateway if you need a RESTful API to connect to an identity provider or want to leverage Amazon WAF for its geo-blocking and rate limiting capabilities. Visit the documentation to learn more about integrating common identity providers such as Amazon Cognito, Okta, and Amazon Secrets Manager.

Q: How can I get started with integrating my existing identity provider for Custom authentication?

A: To get started, you can use the Amazon CloudFormation template in the usage guide and supply the necessary information for user authentication and access. Visit the website on custom identity providers to learn more.

Q: Are anonymous users supported?

A: No, anonymous users are currently not supported for any of the protocols.

Q: When setting up my users via a custom identity provider, what information is used to enable access to my users?

A: Your user will need to provide a username and password (or SSH key) which will be used to authenticate, and access to your bucket is determined by the Amazon IAM Role supplied by the API Gateway and Lambda used to query your identity provider. You will also need to provide home directory information, and it is recommended that you lock them down to the designated home folder for an additional layer of security and usability. 

AS2 trading partners

Q: How do I uniquely identify my AS2 trading partner?

A: Your trading partner is uniquely identified using their AS2 Identifier (AS2 ID), Similarly your trading partners identify your messages using your AS2 ID.

Q: Which existing features of Amazon Transfer Family are available for AS2? Which features are not available?

A: You can use Amazon Transfer Family’s existing support for Amazon S3, networking features (VPC endpoints, Security Groups, and Elastic IPs), and access controls (Amazon IAM) for AS2, as you could for SFTP, FTPS, and FTP. User authentication, logical directories, custom banners, and Amazon EFS as a storage backend are not supported for AS2.

Q: What is non-repudiation and why is it important?

A: Non-repudiation, unique to AS2, validates that message are successfully exchanged between two parties. Non-repudiation in AS2 is achieved using Message Disposition Notifications (MDN). When an MDN is requested in a transaction, it ensures that the sender sent the message, the receiver successfully received it, and the message sent by the sender was the same message received by the receiver.

Q: What are the steps involved in message transmission using the AS2 protocol?

A: There are two aspects to messages transmission – one from the sender and from the receiver. Once the sender has determined what message to send, the message is signed (using the sender’s private key), encrypted (using the receiver’s certificate), and the message integrity is calculated using a hash. This signed and encrypted message is transmitted over the wire to the receiver. Once the message is received, it is decrypted (using the receiver’s private key), validated (using the sender’s public key), processed and a signed Message Disposition Notifications (MDN), if requested, is sent back to the sender to acknowledge successful delivery of the message. Refer to the documentation on how AS2 handles message transmission.

Q: What are the options available for message transmission?

A: The combination of options possible are driven from a sender’s standpoint. The sender can choose to either only encrypt or only sign the data (or both), and choose to request an Message Disposition Notifications (MDN). If the sender chooses to request an MDN, they can request a signed or unsigned MDN. The receiver is expected to honor these options.

Q: Are requesting Message Disposition Notifications (MDN) optional?

A: Yes, the sender can choose to request an MDN, choose to request a signed or unsigned MDN, as well as select the signing algorithms that should be used to sign the MDN.

Q: Do you support synchronous (Sync) and asynchronous (Async) Message Disposition Notifications (MDN)? When should I use which option?

A: Currently we only support synchronous MDN. Since synchronous MDNs are sent over the same connection channel as the message, it is much simpler and hence the recommended option. If you need more time to process the message before sending an MDN, Async MDNs are preferred. 

Q: How do I track and search for payloads and MDNs sent and received?

A: Amazon Transfer Family extracts key AS2 information from payloads and MDNs exchanged and stores them as JSON files in your Amazon S3 bucket. You can query these JSON files using Amazon S3 Select or Amazon Athena, or index the files using Amazon OpenSearch or Amazon DocumentDB for analytics.

Q: Can I archive the received MDNs (as the sender who requested them)?

A: Yes, once you receive an MDN from your trading partner, the service validates the MDN using your certificate and stores the message in your Amazon S3 bucket. You can choose to archive the message by leveraging S3 Lifecycle policies.

Q: How do I notify Amazon Transfer Family when a message is ready for delivery to my trading partner’s endpoint?

A: Once your data is ready for delivery, you will need to invoke a service provided API, associate a connector to notify us that it is ready to be delivered, and provide us the recipient’s information. This will notify the service to send the message to your trading partner’s endpoint. Refer to the documentation on connectors to send messages to your trading partner over AS2.

Q: Can I isolate each of my trading partners to use different inbound and outbound locations for messages?

A: Yes, when you set up your trading partner’s profile you can use different folders for each of them.

Q: Can I use my trading partner's existing keys and certificates with my Amazon Transfer Family AS2 endpoint?

A: Yes, you can import your partner’s existing keys and certificates and manage renewals and rotations. Refer to the documentation on importing certificates.

Q: How do I know when my trading partner’s certificates are expiring?

A: Using the Amazon Transfer Family console, you can view a dashboard of certificates sorted by their expiry dates. Additionally, you can opt in to receive notifications ahead of certificate expiry, giving you sufficient time to rotate them to prevent discontinuity in operations.

Q: Is Amazon Transfer Family support for AS2 Drummond Certified?

A: No. Amazon Transfer Family support for AS2 is currently Drummond Pre-Certified and will become Drummond Certified in 2023. Visit this announcement to learn more.

Q: Do you support AS3 and AS4?

A: No.

Managed Workflows for Post Upload Processing

Q: What is managed workflows for post-upload processing?

A: Amazon Transfer Family managed workflows make it easier for you to create, run, and monitor post upload processing for file transfers over SFTP, FTPS, and FTP. Using this feature, you can save time with low code automation to coordinate all the necessary tasks such as copying and tagging. You can also customize to scan for PII, virus/malware, or other errors such as incorrect file format or type, enabling you to quickly detect anomalies and meet your compliance requirements.

Q: Why do I need managed workflows?

A: If you need to process files that you exchange with your business partners using Amazon Transfer Family, you need to set up an infrastructure to run custom code, continuously monitor for run time errors and anomalies, and make sure all changes and transformations to the data are audited and logged. Additionally, you need to account for error scenarios, both technical and business, while ensuring failsafe modes are properly triggered. If you have requirements for traceability, you need to track lineage of the data as it passes along different components of your system. Maintaining separate components of a file-processing workflow takes time away from focusing on differentiating work you could be doing for your business. Managed workflows remove the complexities of managing multiple tasks, and provides a standardized file-processing solution that can be replicated across your organization, with built-in exception handing and file traceability for each step to help you meet your business requirements.

Q: What are the benefits of using managed workflows?

A: Managed workflows allow you to easily preprocess data before it is consumed by your downstream applications by orchestrating file-processing tasks such as moving files to user-specific folders, encrypting files in-transit, malware scanning, and tagging. You can deploy workflows using Infrastructure as Code (IaC), enabling you to quickly replicate and standardize common post-upload file processing tasks spanning multiple business units in your organization. Managed workflows are only triggered on fully uploaded files, ensuring the data quality is maintained. Built-in exception handling allows you to quickly react to file-processing outcomes helping you maintain your business and technical SLAs, while offering you control on how to handle failures. Lastly, each workflow step produces detailed logs, which can be audited to trace the data lineage.

Q: How do I get started with workflows?

A: First, set up your workflow to contain actions such as copying, tagging, and a series of actions that can include your own custom step in a sequence of steps based on your requirements. Next, map the workflow to a server, so on file arrival, actions specified in this workflow are evaluated and triggered in real time. To learn more, visit the documentation.

Q: Can I use the same workflow setup across multiple servers?

A: Yes. The same workflow can be assigned to multiple servers so it is easier for you to maintain and standardize configurations.

Q: What actions can I take on my files using workflows?

A: The following common actions are available once a transfer server has received a file from the client:

  • Move or copy data from where it arrives to where it needs to be consumed.
  • Delete the original file post archiving or copying to a new location.
  • Tag the file based on its contents so it can be indexed and searched by downstream services (S3 only).
  • Any custom file processing logic by supplying your own Lambda function as a custom step to your workflow. For example, checking compatibility of the file type, scanning files for malware, decrypting files, detecting Personally Identifiable Information (PII), and metadata extraction before ingesting files to your data analytics.

Q: Can I use workflows to automatically decrypt files using PGP?

A: Yes. You can use a custom workflow step to decrypt PGP encrypted files upon upload. If you are looking for a fully managed solution for PGP decryption, reach out to us via Amazon Web Services China Support.

Q: Can I select which file to process at each workflow step?

A: Yes. You can configure a workflow step to process either the originally uploaded file or the output file from the previous workflow step. This allows you to easily automate moving and renaming of your files after they are uploaded to Amazon S3. For example, to move a file to a different location for file archival or retention, configure two steps in your workflow. The first step is to copy a file to a different Amazon S3 location, and the second step to delete the originally uploaded file. Read the documentation for more details on selecting a file location for workflow steps.

Q: Can I preserve the originally uploaded file for records retention?

A: Yes. Using workflows, you can create multiple copies of the original file while preserving the original file for records retention.

Q: Can I use workflows to dynamically route files to user-specific Amazon S3 folders?

A: Yes. You can utilize username as a variable in workflows copy steps, enabling you to dynamically route files to user-specific folders in Amazon S3. This removes the need to hardcode destination folder location when copying files and automates creation of user-specific folders in Amazon S3, allowing you to scale your file automation workflows. Read the documentation to learn more.

Q: How do I monitor my workflows?

A: Workflow executions can be monitored using Amazon CloudWatch metrics such as the total number of workflows executions, successful executions, and failed executions. Using the Amazon Transfer Family Console, you can also search and view real-time status of in progress Workflow executions. Use Amazon CloudWatch logs to get detailed logging of workflows executions.

Q: What types of notifications can I receive?

A: You can use the custom processing step to trigger notifications to Amazon EventBridge or Amazon Simple Notification Service (SNS) and get notified when file processing is complete. Additionally, you can also use Amazon CloudWatch logs from Amazon Lambda executions to get notifications.

Q: I am using Amazon Step Functions to orchestrate my file-processing steps. How do Amazon Transfer Family managed workflows differ from my current Amazon Step Functions set up?

A: Amazon Step Functions is a serverless orchestration service that lets you combine Amazon Lambda with other services to define the execution of business application in simple steps. To perform file-processing steps using Amazon Step Functions, you use Amazon Lambda functions with Amazon S3’s event triggers to assemble your own workflows. Managed workflows provide a framework to easily orchestrate a linear sequence of processing and differentiates from existing solutions in the following ways: 1) Only full file uploads trigger workflows to be executed, 2) workflows can be triggered automatically for Amazon S3 as well as Amazon EFS (which doesn’t offer post upload events), and 3) customers can get end to end visibility into their file transfers and processing in Amazon CloudWatch logs.

Q: Can I send a notification if a file validation check fails?

A: Yes. If a file validation check fails against preconfigured validation steps, you can use the exception handler to invoke your monitoring system or team members via Amazon SNS topic.

Q: Can I trigger workflow actions based on the exchange of messages over AS2?

A: No, you cannot currently use managed workflows with AS2.

Q: Can I trigger workflow actions on user downloads?

A: No. Processing can be invoked only on file arrival using the inbound endpoint.

Q: Can I trigger the same workflow on batches of files in a session?

A: No. Workflows currently process one file per execution.

Q: Can workflows be triggered on partial uploads?

A: No. Only completed and full file uploads will trigger processing by workflows.

Amazon S3 Access

Q: Why do I need to provide an Amazon IAM Role and how is it used?

A: Amazon IAM is used to determine the level of access you want to provide your users. This includes the operations you want to enable on their client and which Amazon S3 buckets they have access to – whether it’s the entire bucket or portions of it.

Q: Why do I need to provide home directory information and how is it used?

A: The home directory you set up for your user determines their login directory. This would be the directory path that your user’s client will place them in as soon as they are successfully authenticated into the server. You will need to ensure that the IAM Role supplied provides user access to the home directory.

Q: I have 100s of users who have similar access settings but to different portions of my bucket. Can I set them up using the same IAM Role and policy to enable their access?

A: Yes. You can assign a single IAM Role for all your users and use logical directory mappings that specify which absolute Amazon S3 bucket paths you want to make visible to your end users and how you these paths presented to them by their clients.

Q: How are files stored in my Amazon S3 bucket transferred using Amazon Transfer?

A: Files transferred over the supported protocols are stored as objects in your Amazon S3 bucket, and there is a one-to-one mapping between files and objects enabling native access to these objects using Amazon Web Services services for processing or analytics.

Q: How are Amazon S3 objects stored in my bucket presented to my users?

A: After successful authentication, based on your users’ credentials, the service presents Amazon S3 objects and folders as files and directories to your users’ transfer applications.

Q: What file operations are supported? What operations are not supported?

A: Common commands to create, read, update, and delete, files and directories are supported. Files are stored as individual objects in your Amazon S3 bucket. Directories are managed as folder objects in S3, using the same syntax as the S3 console.

Directory rename operations, append operations, changing ownerships, permissions and timestamps, and use of symbolic and hard links are currently not supported.

Q: Can I control which operations my users are allowed to perform?

A: Yes, you can enable/disable file operations using the Amazon IAM role you have mapped to their username. Refer to the documentation on 'Creating IAM Policies and Roles to control your end users’ access

Q: Can I provide my end users access to more than one Amazon S3 bucket?

A: Yes. The bucket(s) your user can access is determined by the  IAM Role, and the optional scope-down policy you assign for that user. You can only use a single bucket as the home directory for the user.

Q: Can I create a server using Amazon Web Services Account A and map my users to Amazon S3 buckets owned by Amazon Web Services Account B?

A: Yes. You can use the CLI and API to set up cross account access between your server and the buckets you want to use for storing files transferred over the supported protocols. The Console drop down will only list buckets in Account A. Additionally, you’d need to make sure the role being assigned to the user belongs to Account A.

Q: Can I automate processing of a file once it has been uploaded to Amazon S3?

A: Yes, you can use Amazon S3 events to automate post upload processing using a broad array of Amazon Web Services services for querying, analysis, machine learning and more. Visit the documentation to learn more on common examples for post upload processing using Lambda with Amazon S3.

Q: Can I customize rules for processing based on the user uploading the file?

A: Yes. When your user uploads a file, the username and the server id of the server used for the upload is stored as part of the associated S3 object’s metadata. You can use this information for post upload processing. Refer to the documentation on information you use for post upload processing.

Amazon EFS Access

Q: How do I set up my EFS file system to work with Amazon Transfer Family?

A: Prior to setting up Amazon Transfer Family to work with an Amazon EFS file system, you will need to set up ownership of files and folders using the same POSIX identities (user id/group id) you plan to assign to your Amazon Transfer Family users. Additionally, if you are accessing file systems in a different account, resource policies must also be configured on your file system to enable cross account access.

Q: How do I provide access to my users to upload/download files to/from my file systems?

A: Amazon EFS uses POSIX IDs which consist of an operating system user id, group id, and secondary group id to control access to a file system. When setting up your user in the Amazon Transfer Family console/CLI/API, you will need to specify the username, user’s POSIX configuration, and an IAM role to access the EFS file system. You will also need to specify an EFS file system id and optionally a directory within that file system as your user’s landing directory. When your Amazon Transfer Family user authenticates successfully using their file transfer client, they will be placed directly within the specified home directory, or root of the specified EFS file system. Their operating system POSIX id will be applied to all requests made through their file transfer clients. As an EFS administrator, you will need to make sure the file and directories you want your Amazon Transfer Family users to access are owned by their corresponding POSIX ids in your EFS file system. Refer to the documentation to learn more on configuring ownership of sub-directories in EFS.

Q: How are files transferred over the protocols stored in my Amazon EFS file systems?

A: Files transferred over the enabled protocols are directly stored in your Amazon EFS file Systems and will be accessible via a standard file system interface or from Amazon Web Services services that can access Amazon EFS file systems.

Q: What file operations are supported over the protocols when using Amazon S3 and Amazon EFS?

A: SFTP/FTPS/FTP commands to create, read, update, and delete files, directories, and symbolic links are supported. Refer to the table below on supported commands for EFS as well as S3.

Command Amazon S3 Amazon EFS
     cd Supported Supported
     ls/dir Supported Supported
     pwd Supported Supported
     put Supported Supported
     get Supported Supported including resolving symlinks
     rename Supported1 Supported
     chown Not supported Supported2
     chmod Not supported Supported2
     chgrp Not supported Supported3
     ln -s/symlink Not supported Not supported
     mkdir Supported Supported
     rm/delete Supported Supported
     rmdir Supported4 Supported
     chmtime Not supported Supported

1 Only file renames are supported. Directory renames and rename of files to overwrite existing files are not supported.

2 Only root i.e. users with uid=0 can change ownership and permissions of files and directories.

3 Supported either for root e.g. uid=0 or for the file’s owner who can only change a file’s group to be one of their secondary groups.

4 Supported for non-empty folders only.

Q: How can I control which files and folders my users have access to and which operations they are allowed to and not allowed to perform?

A: The IAM policy you supply for your Amazon Transfer Family user determines if they have read-only, read-write, and root access to your file system. Additionally, as a file system administrator, you can set up ownership and grant to access files and directories within your file system using their user id and group id. This applies to users whether they are stored within the service (service managed) or within your identity management system (“BYO Auth”).

Q: Can I restrict each of my users to access different directories within my file system and only access files within those directories?

A: Yes, when you set up your user, you can specify different file systems and directories for each of your users. On successful authentication, EFS will enforce a directory for every file system request made using the enabled protocols.

Q: Can I hide the name of the file system from being exposed to my user?

A: Yes, using Amazon Transfer Family’s logical directory mappings, you can restrict your end users’ view of directories in your file systems by mapping absolute paths to end user visible path names. This also includes being able to “chroot” your user to their designated home directory.

Q: Are symbolic links supported?

A: Yes, if symbolic links are present in directories accessible to your user and your user tries to access them, the links will be resolved to its target. Symbolic links are not supported when you use logical directory mappings to set up your users' access.

Q: Can I provide an individual SFTP/FTPS/FTP user access to more than one file system?

A: Yes, when you set up an Amazon Transfer Family user, you can specify one or more file systems in the IAM policy you supply as part of your user set up in order to grant access to multiple file systems.

Q: What operating systems can I use to access my EFS file systems via Amazon Transfer Family?

A: You can use clients and applications built for Microsoft Windows, Linux, macOS, or any operating system that supports SFTP/FTPS/FTP to upload and access files stored in your EFS file systems. Simply configure the server and user with the appropriate permissions to the EFS file system to access the file system across all operating systems.

Q: How do I know which user uploaded a file?

A: For new files, the POSIX user id associated with the user uploading the file will be set as the owner of the file in your EFS file system. Additionally, you can use Amazon CloudWatch to track your users’ activity for file creation, update, delete, and read operations. Visit the documentation to learn more on how to enable Amazon CloudWatch logging.

Q: Can I view how much data was uploaded and downloaded over the enabled protocols?

A: Yes, metrics for data uploaded and downloaded using your server are published to Amazon CloudWatch within the Amazon Transfer Family namespace. Visit the documentation to view the available metrics for tracking and monitoring.

Q: Can I use Amazon Transfer Family to access a file system in another account?

A: Yes. You can use the CLI and API to set up cross account access between your Amazon Transfer Family resources and EFS file systems. The Amazon Transfer Family console will only list file systems in the same account. Additionally, you’d need to make sure the IAM role assigned to the user to access the file system belongs to Account A.

Q: What happens if my EFS file system does not have the right policies enabled for cross account access?

A: If you set up an Amazon Transfer Family server to access a cross account EFS file system not enabled for cross account access, your SFTP/FTP/FTPS users will be denied access to the file system. If you have CloudWatch logging enabled on your server, cross account access errors will be logged to your CloudWatch Logs.

Q: Can I use Amazon Transfer Family to access an EFS file system in a different Amazon Web Services Region?

A: No, you can use Amazon Transfer Family to access EFS file systems in the same Amazon Web Services Region only.

Q: Can I use Amazon Transfer Family with all EFS storage classes?

A: Yes. You can use Amazon Transfer to write files into EFS and configure EFS Lifecycle Management to migrate files that have not been accessed for a set period of time to the Infrequent Access (IA) storage class.

Q: Can my applications use SFTP/FTPS/FTP to concurrently read and write data from/to the same file?

A: Yes, Amazon EFS provides a file system interface, file system access semantics (such as strong consistency and file locking), and concurrently-accessible storage for up to thousands of NFS/SFTP/FTPS/FTP clients.

Q: Will my EFS burst credits be consumed when I access my file systems using Amazon Transfer Family?

A: Yes. Accessing your EFS file systems using your Amazon Transfer Family servers will consume your EFS burst credits regardless of the throughput mode. Refer to the documentation on available performance and throughput modes and view some useful performance tips.

Security and compliance

Q: Which protocols should I use for securing data while in-transit over a public network?

Either SFTP or FTPS should be used for secure transfers over public networks. Due to the underlying security of the protocols based on SSH and TLS cryptographic algorithms, data and commands are transferred through a secure, encrypted channel.

Q: What are my options to encrypt data at rest?

A: You can choose to encrypt files stored your bucket using Amazon S3 Server-Side Encryption (SSE-S3) or Amazon KMS (SSE-KMS). For files stored in EFS, you can choose Amazon or customer managed CMK for encryption of files at rest. Refer to the documentation for more details on options for at rest encryption of file data and metadata using Amazon EFS.

Q: Which compliance programs does Amazon Transfer Family support?

A: Amazon Transfer Family is PCI-DSS compliant. The service is also SOC 1, 2, and 3 compliant. Learn more about services in scope by compliance programs.

Q: How can I monitor my end users’ activity?

A: You can use Amazon CloudWatch to monitor your end users’ activity and use Amazon CloudTrail to access a record of all S3 API operations invoked by your server to service your end users’ data requests. Visit the documentation on how to enable Amazon CloudWatch and Amazon CloudTrail logging.

Q: How can I track amount of data uploaded and downloaded over the protocols?

A: You can use Amazon CloudWatch Metrics to monitor and track data uploaded and downloaded by your users over the chosen protocols. Visit the documentation to learn more on using Amazon CloudWatch metrics.

Billing

Q: How am I billed for use of the service?

You are billed on an hourly basis for each of the protocols enabled, from the time you create and configure your server endpoint, until the time you delete it. You are also billed based on the amount of data uploaded and downloaded over SFTP, FTPS, or FTP and number of messages exchanged over AS2. Refer to the pricing page for more details

Q: Will my billing be different if I use the same server endpoint for multiple protocols or use different endpoints for each protocol?

A: No, you are billed on an hourly basis for each of the protocols you have enabled and for the amount of data transferred through each of the protocols, regardless of whether same endpoint is enabled for multiple protocols or you are using different endpoints for each of the protocols.

Q: I have stopped my server. Will I be billed while it is stopped?

A: Yes, stopping the server, by using the console, or by running the “stop-server” CLI command or the “StopServer” API command, does not impact billing. You are billed on an hourly basis from the time you create your server endpoint and configure access to it over one or more protocols until the time you delete it.

Managed Workflows

Q: What are the benefits of using managed workflows?

A: Managed workflows allow you to easily preprocess data before it is consumed by your downstream applications by orchestrating file-processing tasks such as moving files to user-specific folders, encrypting files in-transit, malware scanning, and tagging. You can deploy workflows using Infrastructure as Code (IaC), enabling you to quickly replicate and standardize common post-upload file processing tasks spanning multiple business units in your organization. You can have granular control by defining managed workflows that are triggered only on fully uploaded files, to ensure data quality is maintained, and by defining managed workflows that are triggered for partially uploaded files, to configure processing for incomplete uploads. Built-in exception handling allows you to quickly react to file-processing outcomes in case of errors or exceptions in the workflow execution, helping you maintain your business and technical SLAs, while offering you control on how to handle failures. Lastly, each workflow step produces detailed logs, which can be audited to trace the data lineage.

Q: I am using Amazon Step Functions to orchestrate my file-processing steps. How do Amazon Transfer Family managed workflows differ from my current Amazon Step Functions set up?

A: Amazon Step Functions is a serverless orchestration service that lets you combine Amazon Lambda with other services to define the execution of business application in simple steps. To perform file-processing steps using Amazon Step Functions, you use Amazon Lambda functions with Amazon S3’s event triggers to assemble your own workflows. Managed workflows provide a framework to easily orchestrate a linear sequence of processing and differentiates from existing solutions in the following ways: 1) You can granularly define workflows to be executed only on full file uploads, as well as workflows to be executed only on partial file uploads, 2) workflows can be triggered automatically for S3 as well as EFS (which doesn’t offer post upload events), and 3) customers can get end to end visibility into their file transfers and processing in CloudWatch logs.

Q: Can workflows be triggered on partial uploads?

A: Yes. You can define workflows to be triggered on both full as well as partial file uploads.