SFTP Connector

The SFTP connector transfers files to and from a remote SFTP server.

Key Capabilities

SSH-based secure file transfer with public key and password authentication
Advanced authentication including certificate-based client authentication
Resume capability for interrupted uploads and downloads
Advanced SSH encryption algorithms and server thumbprint validation
Connection pooling and temporary file handling for reliable transfers
Optional caching to ensure only new or updated files are downloaded

Overview

Each SFTP connector uploads to a specified folder and downloads from a set of folders on the remote SFTP server. Files that reach the SFTP connector in the Arc flow are uploaded to the upload target folder, and files found in the download target folder(s) are downloaded and entered into the Arc flow. The connector supports upload and download filters to only send and receive specified file names and/or file extensions.

Connector Configuration

This section contains all of the configurable connector properties.

Settings Tab

Host Configuration

Settings related to establishing the connection to the remote SFTP host.

Setting	Description
Connector Id	The static, unique identifier for the connector.
Connector Type	Displays the connector name and a description of what it does.
Connector Description	An optional field to provide a free-form description of the connector and its role in the flow.
Remote Host	The hostname or IP address of the SFTP server.
Remote Port	The port on which to connect to the SFTP server.

Client Authentication

Settings related to authenticating to the SFTP server.

Setting	Description
Authentication Mode	The type of authentication to use with the SFTP server.
User	The username for logging in to the SFTP server.
Password	The password for logging in to the SFTP server.
Client Certificate	The certificate with a private key to use during public key authentication. Only available when Authentication Mode is set to Public Key or Multi-Factor Authentication. Optionally, you can use the Create Certificate button to create a new certificate.
Client Certificate Password	The password required to access the Client Certificate.

Server Authentication

Setting related to verifying the SFTP server’s identity.

Setting	Description
Server Thumbprint	The thumbprint of the certificate that identifies the SFTP server. You can also set this to a certificate file containing the server’s public key. When you test the connection, the connector prompts you to accept/trust the thumbprint presented by the server.

Upload

Setting related to uploading files to the SFTP server.

Setting	Description
Remote Path	Files processed by the connector are uploaded to this remote folder. You can use macros to dynamically create dated folders (such as year or month folders) in your path. For more information, see Macros.

Download

Settings related to downloading from the SFTP server.

Setting	Description
Remote Path	The remote folder from which files are downloaded. Use a comma-delimited list to specify multiple paths. You can use macros to dynamically create dated folders (such as year or month folders) in your path. For more information, see Macros.
File Mask	A glob pattern that determines which files in the Remote Path should be downloaded (for example, *.txt).
Delete files (after received)	Check this to delete successfully downloaded files from the SFTP server.

Caching

Settings related to caching and comparing files between multiple downloads.

Setting	Description
File Size Comparison	Check this to keep a record of downloaded file names and sizes. Previously downloaded files are skipped unless the file size is different than the last download.
Timestamp Comparison	Check this to keep a record of downloaded file names and last-modified timestamps. Previously downloaded files are skipped unless the timestamp is different than the last download.

Arc automatically cleans up the resource cache. This process runs in the background during every receive cycle and removes stale cache entries for files that are no longer present on the remote server. This keeps the cache size manageable without requiring any manual action.

By default, files are retained for 30 days, but you can use the ResourceCacheRetentionDays setting in the Other Settings field on the Advanced tab to adjust it to fit your environment. For example, ResourceCacheRetentionDays=15 retains files for 15 days before removing them.

When you enable caching, the file names are case-insensitive. For example, the connector cannot distinguish between TEST.TXT and test.txt.

Advanced Tab

Server Commands

Advanced Settings

Settings not included in the previous categories.

Setting	Description
Connection Pooling	Check this to have the connector utilize a pool to access and store connections. This is useful in scenarios where the server places restrictions on the frequency of logon attempts.
Download Excluded Extensions	A comma-delimited list of file extensions that should not be downloaded by the connector.
Download Excluded Prefixes	A comma-delimited list of prefixes that instructs the connector not to download filenames that begin with a specified prefix.
Max Download Files	The maximum number of files to be downloaded from the SFTP server in one polling interval. Set to -1 to allow all files to be downloaded.
Minimum File Size	The minimum file size to process, in bytes. If a file being uploaded is smaller than the specified size, it is finalized as Skipped. For files being downloaded, the connector adds a transaction log entry indicating that the file was skipped because of its size.
Maximum File Size	The maximum file size to process, in bytes. If a file being uploaded is larger than the specified size, it is finalized as Skipped. For files being downloaded, the connector adds a transaction log entry indicating that the file was skipped because of its size.
Monitor File Growth	Check this to have the application store the file sizes of the remote files between polling intervals, and only download files that do not change in size. This prevents the connector from downloading files that are still in the process of being written on the server.
Recurse	Check this to download files in subfolders of the target remote path. The subdirectories are preserved for the received files.
Resume Downloads	If enabled, when an error occurs during a file download, the connector stores the portion of the file that was downloaded and attempts to download the remainder of the file on the next download attempt.
Resume Uploads	If enabled, when an error occurs during a file upload, the connector notes the number of bytes that were transferred and attempts to upload the remainder of the file on the next upload attempt.
SSH Encryption Algorithms	A comma-delimited list of algorithms to use during SSH encryption. By default, all algorithms are enabled. Arc supports the following algorithms: aes256-ctr, aes256-cbc, aes192-ctr, aes192-cbc, aes128-ctr, aes128-cbc, 3des-ctr, 3des-cbc, cast128-cbc, blowfish-cbc, arcfour, arcfour128, arcfour256, aes128-gcm@openssh.com, aes256-gcm@openssh.com, chacha20-poly1305@openssh.com
Local File Scheme	A scheme for assigning filenames to messages that are output by the connector. You can use macros in your filenames dynamically to include information such as identifiers and timestamps. For more information, see Macros.
Receive Filter	A glob pattern filter to determine which files should be downloaded from the remote storage (for example, .txt). You can use negative patterns to indicate files that should not* be downloaded (for example, -.tmp). Use this setting when you need multiple File Mask* patterns. Multiple patterns can be separated by commas, with later filters taking priority except when an exact match is found.
Temp Download Extension	A temporary file extension to append to file downloads while the transfer is in progress.
Temp Upload Extension	A temporary file extension to append to file uploads while the transfer is in progress.
Temp Upload Prefix	A temporary file prefix to prepend to file uploads while the transfer is in progress.
Temp Upload Path	A temporary path on the remote SFTP server where files are uploaded. The file is moved into the permanent upload path after the transfer is complete.
Timeout	The length of time (in seconds) the connector waits for a response from the server before throwing a timeout error (the default is 60 seconds).
Wait for Channel Close	Check this to have the connector wait for the server to close the SSH channel before disconnecting. If timeouts occur during the logoff sequence, you should disable this setting.
Use GMT File Time	Check this to have the connector read file timestamps as GMT time, and to use that time for comparisons against the local cache. If you leave this unchecked, timestamps from the server are converted to local time before being used for time comparisons.
Processing Delay	The amount of time (in seconds) by which the processing of files placed in the Transactions tab is delayed. This is a legacy setting. Best practice is to use a File connector to manage local file systems instead of this setting.

Proxy Settings

These are a collection of settings that identify and authenticate to the proxy through which the connection should be routed. By default, this section uses the global settings on the Proxy Settings portion of the Security Settings page. Clear the checkbox to supply settings specific to your connector.

Setting	Description
Proxy Type	The protocol used by a proxy-based firewall.
Proxy Host	The name or IP address of a proxy-based firewall.
Proxy Port	The TCP port for a proxy-based firewall.
Proxy User	The user name to use to authenticate with a proxy-based firewall.
Proxy Password	A password used to authenticate to a proxy-based firewall.
Authentication Scheme	Leave the default None or choose from one of the following authentication schemes: Basic, Digest, Proprietary, or NTLM.

Message

Message settings determine how the connector searches for messages and manages them after processing.

Note: The settings below are deprecated and hidden by default. They appear only on connectors where they were previously enabled or configured to a non-default value. To retain copies of successfully processed files, right-click the connector in the flow, choose Show Success Path, and connect the success path to a File connector.

Setting	Description
Save to Sent Folder (Deprecated)	Copies files processed by the connector to the Sent folder. Disabled by default. Files saved to the Sent folder are not covered by Encryption at Rest.
Sent Folder Scheme (Deprecated)	Groups files in the Sent folder by the selected time interval. Only relevant when Save to Sent Folder is enabled.

Logging

Settings that govern the creation and storage of logs.

Setting	Description
Log Level	The verbosity of logs generated by the connector. When you request support, set this to Debug.
Log Subfolder Scheme	Instructs the connector to group files in the Logs folder according to the selected interval. The Weekly option (which is the default) instructs the connector to create a new subfolder each week and store all logs for the week in that folder. Leaving this setting blank tells the connector to save all logs directly in the Logs folder. For connectors that process many transactions, using subfolders helps keep logs organized and improves performance.
Log Messages	Check this to have the log entry for a processed file include a copy of the file itself. If you disable this, you might not be able to download a copy of the file from the Transactions tab.

Miscellaneous

Miscellaneous settings are for specific use cases.

Setting	Description
Other Settings	Enables you to configure hidden connector settings in a semicolon-separated list (for example, `setting1=value1;setting2=value2`). Normal connector use cases and functionality should not require the use of these settings.

Automation Tab

Automation Settings

Settings related to the automatic processing of files by the connector.

Setting	Description
Upload	Whether files arriving at the connector should automatically be uploaded.
Retry Interval	The number of minutes before a failed upload is retried.
Max Attempts	The maximum number of times the connector processes the input file. Success is measured based on a successful server acknowledgement. If you set this to 0, the connector retries the file indefinitely.
Download	Whether the connector should automatically poll the remote download path(s) for files to download.
Interval	The interval between automatic download attempts.
Minutes Past the Hour	The minutes offset for an hourly schedule. Only applicable when the interval setting above is set to Hourly. For example, if this value is set to 5, the automation service downloads at 1:05, 2:05, 3:05, etc.
Time	The time of day that the attempt should occur. Only applicable when the interval setting above is set to Daily, Weekly, or Monthly.
Day	The day on which the attempt should occur. Only applicable when the interval setting above is set to Weekly or Monthly.
Minutes	The number of minutes to wait before attempting the download. Only applicable when the interval setting above is set to Minute.
Cron Expression	A five-position string representing a cron expression that determines when the attempt should occur. Only applicable when the interval setting above is set to Advanced.
Start Date and Time	The date and time at which the automation first runs. Every run after that follows the interval setting above. The last and next run times appear in the Automation Status section.

Automation Status

Performance

Settings related to the allocation of resources to the connector.

Setting	Description
Max Workers	The maximum number of worker threads consumed from the threadpool to process files on this connector. If set, this overrides the default setting on the Performance Settings portion of the Advanced Settings page.
Max Files	The maximum number of files sent by each thread assigned to the connector. If set, this overrides the default setting on the Performance Settings portion of the Advanced Settings page.

Alerts Tab

SLAs Tab

Establishing a Connection

The following settings are required to connect to a remote SFTP server:

Remote Host
Remote Port
Authentication Mode
User
Password or Client Certificate/Certificate Password
Server Thumbprint

When testing the connection to the server, the connector prompts you to accept/trust the thumbprint of the server’s public key.

Uploading Files

The SFTP connector uploads files from the Transactions tab. Files are automatically uploaded to the SFTP server if Upload Automation is enabled in the connector. Remote Path should be set to the folder on the remote SFTP server where files should be uploaded. You can use macros to dynamically create dated folders (such as year or month folders). The application changes directories to the specified folder after logging in to the server. If any files could not be uploaded, the connector attempts to send them again after Retry Interval minutes have elapsed. This process continues until the Max Attempts setting is reached, after which the connector raises an error and the file is no longer sent automatically.

Downloading Files

Downloaded files are displayed in the Transactions tab of the connector, or passed along to the next connector in the flow. Files are automatically downloaded from the SFTP server if Download Automation is enabled in the connector, and can be manually downloaded by clicking the Receive button on the Transactions tab. Remote Path should be set to the folder on the remote SFTP server from which files should be downloaded. You can use macros to dynamically create dated folders (such as year or month folders). The application changes directories to the specified folder after logging in to the server. The File Mask property filters files so that only filenames matching the glob pattern are downloaded from the server. You can use the Delete files (after download) setting to delete the files on the remote server after successfully downloading them. On the Transactions tab, click the Receive button to test the settings and retrieve the matching files from the server.

Subfolder Headers

If Recurse is checked on the Advanced tab, when receiving a file from the Remote Path in the SFTP connector:

The message for the file that is received contains a Subfolder header in its metadata.
This header contains the subfolder, relative to the Remote Path in the SFTP connector, that the file was received from.
This subfolder header is supported by other connectors that support a subfolder header in Send operations.

When sending files, if a Subfolder header is present on the message that is sent to the Upload Path in the SFTP connector:

The file is placed in the subfolder, relative to the Upload Path in the SFTP connector, that is specified in the subfolder header.
The subfolder is created if permissions are available.

Getting Started

Flows

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Connectors

Mapping

APIs and Automation

How-To Guides

Scripting

Software License and Third-Party Copyrights

Key Capabilities

Overview

Connector Configuration

Settings Tab

Host Configuration

Client Authentication

Server Authentication

Upload

Download

Caching

Advanced Tab

Server Commands

Advanced Settings

Proxy Settings

Message

Logging

Miscellaneous

Automation Tab

Automation Settings

Automation Status

Performance

Alerts Tab

SLAs Tab

Establishing a Connection

Uploading Files

Downloading Files

Subfolder Headers

Macros

Examples

​Key Capabilities

​Overview

​Connector Configuration

​Settings Tab

​Host Configuration

​Client Authentication

​Server Authentication

​Upload

​Download

​Caching

​Advanced Tab

​Server Commands

​Advanced Settings

​Proxy Settings

​Message

​Logging

​Miscellaneous

​Automation Tab

​Automation Settings

​Automation Status

​Performance

​Alerts Tab

​SLAs Tab

​Establishing a Connection

​Uploading Files

​Downloading Files

​Subfolder Headers

​Macros

​Examples

Key Capabilities

Overview

Connector Configuration

Settings Tab

Host Configuration

Client Authentication

Server Authentication

Upload

Download

Caching

Advanced Tab

Server Commands

Advanced Settings

Proxy Settings

Message

Logging

Miscellaneous

Automation Tab

Automation Settings

Automation Status

Performance

Alerts Tab

SLAs Tab

Establishing a Connection

Uploading Files

Downloading Files

Subfolder Headers

Macros

Examples