S3 Poller

Overview

You can use this Snap to check the list of files in a given directory (including subdirectories as an option) periodically and produce output documents if the file names match a given filter.



Prerequisites

  • A valid account with the required permissions.

Snap views

View Description Examples of upstream and downstream Snaps
Input An optional document to evaluate expressions in the Directory and/or File filter properties. Note that each input document will trigger the execution of the Snap.
Output A full path in each document as a value for a key "path". If multiple files match the filter, the same number of documents will be provided in the output view after each interval.
[
  {
    "bucket" : "yourbucket",
    "objectKey" : "tmp/test1.json",
    "path" : "s3:///yourbucket/tmp/test1.json",
    "lastModified" : "2025-02-27T03:23:00.000Z"
  },
  {
    "bucket" : "yourbucket",
    "objectKey" : "tmp/test2.json",
    "path" : "s3:///yourbucket/tmp/test2.json",
    "lastModified" : "2025-02-27T03:22:57.000Z"
  }
]
Error

Error handling is a generic way to handle errors without losing data or failing the Snap execution. You can handle the errors that the Snap might encounter when running the pipeline by choosing one of the following options from the When errors occur list under the Views tab. The available options are:

  • Stop Pipeline Execution Stops the current pipeline execution when an error occurs.
  • Discard Error Data and Continue Ignores the error, discards that record, and continues with the remaining records.
  • Route Error Data to Error View Routes the error data to an error view without stopping the Snap execution.

Learn more about Error handling in Pipelines.

Snap settings

Legend:
  • Expression icon (): Allows using pipeline parameters to set field values dynamically (if enabled). SnapLogic Expressions are not supported. If disabled, you can provide a static value.
  • SnapGPT (): Generates SnapLogic Expressions based on natural language using SnapGPT. Learn more.
  • Suggestion icon (): Populates a list of values dynamically based on your Snap configuration. You can select only one attribute at a time using the icon. Type into the field if it supports a comma-separated list of values.
  • Upload : Uploads files. Learn more.
Learn more about the icons in the Snap settings dialog.
Field / Field set Type Description
Label String

Required. Specify a unique name for the Snap. Modify this to be more appropriate, especially if more than one of the same Snaps is in the pipeline.

Default value: S3 Poller

Example: S3 Poller
Bucket String/Expression/ Suggestion

Required. Specify or select an S3 bucket.

Default value: N/A

Examples: test-bucket
Directory String/Expression/ Suggestion

Enter a directory as a prefix of an S3 object key ending with ‘/'. It should not start with '/’. Leave it empty if you are polling the bucket root.

Note:

  • The Snap generates a list of S3 objects in the current directory that match the specified filter when the Include subdirectories checkbox is deselected.

  • This field serves as the prefix substring of the S3 object key name and must end with '/'. If it does not, the Snap appends one. It should not begin with '/'; if it does, the Snap removes it."

Default value: N/A

Examples: faculty/department/
Include subdirectories Checkbox/Expression Select this checkbox to list all matching files in the specified directory and all subdirectories.

Default status: Deselected
Filter (glob) String/Expression

Specify a GLOB pattern filter to match the file names in the directory. The Snap applies this filter to file names only, without including the directory path.

Default value: N/A

Example:

  • *.txt

  • ab????xx.csv
Polling interval (seconds)* Integer/Expression

Required. Specify the time gap between each poll request (in seconds).

Default value: 30

Example: 10
Polling timeout Integer/Expression

Required. Specify the maximum time for which the Snap continues to poll. If the Polling timeout is set to:

  • Greater than 0, for example, 60 seconds, the polling stops after 60 seconds.

  • 0, the Snap processes only one poll.

Default value: 30

Example: 20
Polling-timout unit Dropdown list/Expression Specify a time unit for polling timeout.

Default value: MINUTES

Example: SECONDS
Advanced properties
Maximum retries Integer/Expression Enter the maximum number of retries the Snap performs when it fails to list a directory.

Default value: 3

Example: 5
Only output on change Checkbox/Expression Select this checkbox, to output documents for matching files only when it starts up or when the file changes. Deselect this checkbox to output documents for matching files in every interval.

Default status: Selected
Exit on first matches Checkbox/Expression Select this checkbox to enable the Snap to exit after the interval when one or more matches are found for the first time.

Default status: Deselected
Snap execution Dropdown list
Choose one of the three modes in which the Snap executes. Available options are:
  • Validate & Execute: Performs limited execution of the Snap and generates a data preview during pipeline validation. Subsequently, performs full execution of the Snap (unlimited records) during pipeline runtime.
  • Execute only: Performs full execution of the Snap during pipeline execution without generating preview data.
  • Disabled: Disables the Snap and all Snaps that are downstream from it.

Default value: Execute only

Example: Validate & Execute

Examples