FTP

The File Transfer Protocol (FTP) is a standard network protocol used to transfer computer files between a client and server on a computer network. FTP is built on a client-server model architecture and uses separate control and data connections between the client and the server.

This connector is available in the following products and regions:

Known issues and limitations

• This article describes the operations only for the FTP managed connector, which is available for Azure Logic Apps, Power Automate, and Power Apps. The FTP built-in connector is available only for Standard logic app workflows in Azure Logic Apps. For more information about the FTP built-in connector in Azure Logic Apps, review Connect to FTP servers from workflows in Azure Logic Apps.

• FTP triggers now return only metadata or properties, not file content. However, you can follow these triggers with the action named Get file content. To make sure that a trigger returns one file at a time, rather than a list, make sure to enable the trigger's "Split On" option. For more information about this option in Azure Logic Apps, review Trigger multiple runs.

• FTP triggers work only on the specified folder, not subfolders. To also check a folder's subfolders, set up a separate flow for each subfolder.

• By default, FTP managed connector actions can read or write files that are 50 MB or smaller. To handle files larger than 50 MB, you can use the use the FTP managed connector action named Get file content, which implicitly uses message chunking. Other FTP managed connector actions also support enabling message chunking.

• FTP triggers might experience delays or incomplete results when returning newly created, added, or updated files.

  When an FTP trigger checks for a newly added or changed file, the trigger also confirms that the file is complete. For example, a file might have changes in progress when the trigger checks the FTP server. To avoid returning an incomplete file, the trigger notes the file's timestamp, but doesn't immediately return the file. Instead, the trigger returns the file only when the trigger checks the server again. Sometimes, this behavior might cause a delay that lasts up to twice the trigger's polling interval. Due to this behavior, the FTP trigger might not return all files at the same time if you disable the FTP trigger's Split On setting,

• FTP managed connector triggers might experience missing, incomplete, or delayed results when the "last modified" timestamp is preserved.

  • Missing results

    FTP triggers work by polling, or checking, the FTP file system and looking for any files that changed since the last poll. The FTP managed connector triggers compare file versions using the file's last modified timestamp.

    If you create, add, or update file with a timestamp that's earlier than the currently tracked last modified timestamp, the FTP managed connector trigger won't detect this file. On the other hand, the FTP built-in connector trigger in Standard logic app workflows doesn't have this limitation.

    So, if you use an external tool or client that creates, adds, or updates files on the FTP server, make sure that you disable any feature in the tool or client that preserves a file's last modified timestamp.

    The following table lists some commonly used tools that preserve this timestamp and the steps to disable this feature:

    FTP client	Action
    WinSCP	Go to Options > Preferences > Transfer > Edit > Preserve timestamp > Disable.
    FileZilla	Go to Transfer > Preserve timestamps of transferred files > Disable.

  • Incomplete or delayed results

    When an FTP trigger checks for a newly created, added, or updated file, the trigger also checks whether the file is complete. For example, a file might have changes in progress when the trigger checks the FTP server. To avoid returning an incomplete file, the trigger notes the file's timestamp, but doesn't immediately return the file. Instead, the trigger returns the file only when the trigger checks the server again.

    Sometimes, this behavior might cause a delay that lasts as long as almost twice the trigger's polling interval. Due to this behavior, if you disable the FTP trigger's Split On setting, the FTP trigger might not return all files at the same time.

Requirements

• The FTP connector requires your FTP host server address and account credentials.

• The FTP connector requires access to the FTP server from or through the internet. For more information about allowing traffic to your FTP server using specific IP ranges, review Managed connector IP addresses.

• The FTP connector requires the FTP server to operate or accept in passive mode.

• The FTP connector requires the FTP server to enable the following commands and to support folders that contain whitespace so the commands can work correctly. For the LIST command, make sure the command returns the year component for file timestamps older than 6 months.

  • APPE
  • DELE
  • LIST
  • MDTM
  • RENAME
  • RETR
  • SIZE
  • STOR

• For secure FTP, make sure to set up explicit File Transfer Protocol Secure (FTPS), rather than implicit FTPS. Also, some FTP servers, such as ProFTPd, require that you enable the NoSessionReuseRequired option if you use Transport Layer Security (TLS) mode, the successor to Secure Socket Layer (SSL).

  The FTP connector doesn't work with implicit FTPS and supports only explicit FTP over FTPS, which is an extension of TLS.

FTP connections

• To improve performance for both the FTP connector and FTP server, you can keep your FTP connection open and active after the connector completes a request.

  When you create a connection to an FTP server, the connection profile box that appears has a setting named Close connection after request completion. This setting specifies whether to close the FTP server connection every time after an request completes. If you keep this setting disabled, the connection won't close after a request completes and stays active for future use.

• If your workflow instances run in parallel, you might experience intermittent connectivity errors. Some operations in your workflow might forcibly close the connection even while other operations in the workflow are still using that connection.

  To avoid this scenario, try the following recommendations:

  • When you create the connection, enable the Close connection after request completion setting.

  • Turn off any parallelization or concurrency that's enabled on triggers or actions. For more information about this solution in Azure Logic Apps, review the following documentation:

    • Change trigger concurrency
    • Chanage "For each" action concurrency

  • Avoid running multiple parallel flows.

Use the "Create file" action with and without chunking

For the Create file action, the behavior depends on the action's Allow chunking setting and the size of the file to create:

• Allow chunking enabled:

  • File size is equal or less than 50 MB: The action uploads the file with a single request, uses the original file name, and locks the file during the upload.

  • File size is greater than 50 MB: The action creates the file with the name format, file-name.new-GUID.ms.partial, and uploads the file using multiple requests, or message chunking. After the action uploads the last chunk, the action renames the file with the original file name.

• Allow chunking disabled: The action uploads the file with a single request, uses the original file name, and locks the file during the upload.

Connector how-to guide

For information about how to use the FTP managed connector and built-in connector in Azure Logic Apps, review Connect to FTP servers from workflows in Azure Logic Apps.

General Limits

Creating a connection

The connector supports the following authentication types:

Default

Applicable: All regions

Parameters for creating connection.

This is not shareable connection. If the power app is shared with another user, another user will be prompted to create new connection explicitly.

Throttling Limits

Actions

Copy file

Create file

Delete file

Extract archive to folder

Get file content

Get file content using path

Get file metadata

Get file metadata using path

List files in folder

List files in root folder

Update file

Triggers

When a file is added or modified (properties only)

When a file is added or modified [DEPRECATED]

Definitions

BlobMetadata

binary