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Version: 2.0.0

Source Email

Purpose​

Defines the specific source parameters for an Email connected endpoint.

This Asset can be used by:​

Asset typeLink
Input ProcessorsStream Input Message

Prerequisite​

You need:

Configuration​

Name & Description​

Name & Description (Email Source)

  • Name : Name of the Asset. Spaces are not allowed in the name.

  • Description : Enter a description.

The Asset Usage box shows how many times this Asset is used and which parts are referencing it. Click to expand and then click to follow, if any.

Required roles​

In case you are deploying to a Cluster which is running (a) Reactive Engine Nodes which have (b) specific Roles configured, then you can restrict use of this Asset to those Nodes with matching roles. If you want this restriction, then enter the names of the Required Roles here. Otherwise, leave empty to match all Nodes (no restriction).

Throttling & Failure Handling​

Throttling​

The following parameters allow to control the maximum number of new stream creations per given time period.

  • Max. new streams: Maximum number of streams this source is supposed to open resp. process within a given time period.
  • Per: Time interval unit for the provided Max. new streams number from the drop-down list.
info

Configuration values for this parameter are dependent on the use case scenario. Assuming your data arrives in low frequency cycles these values are negligible. In scenarios with many objects arriving in short time frames it is recommended to have a closer look on adapting the default values.

Backoff Failure Handling​

These parameters define the backoff timing intervals in case of failures. Based on the following parameters, the system will step by step throttle down the processing cycle based on the time boundaries of min. failure backoff and max. failure backoff. It thereby allows to slow down the processing during failure scenarios.

  • Min. failure backoff: The minimum backoff time before the next source item processing (in case of failure scenario).
  • Unit: The Unit that goes with the given minimum time value.
  • Max. failure backoff: The maximum backoff time before the next source item processing (in case of failure scenario).
  • Unit: The Unit that goes with the given maximum time value.

Based on these values the next processing will be delayed: starting with the min. failure backoff time interval the waiting time will be increased step by step up to the max. failure backoff.

  • Reset after number of successful streams: The backoff failure throttling reset.
  • Reset after time without failure streams: Time-based reset for backoff failure throttling .
  • Unit: The Unit that goes with the given time-based backoff failure throttling reset.

Whatever comes first will reset the failure scenario throttling after the system is back to successful stream processing.

Polling & Processing​

This source does not reflect a stream, but an object based storage source which does not signal the existence of new objects to observers. We therefore need to define how often we want to look-up (poll) the source for new objects to process.

You can choose between Fixed rate polling and Cron tab style polling:

Fixed rate​

Use Fixed rate if you want to poll in constant and frequent intervals.

  • Polling interval [sec]: Enter the interval in seconds in which the configured source should be queried for new objects.

Cron tab​

Use Cron tab if you want to poll at determined times. The Cron tab expression follows the cron tab style convention which may be familiar to you. In all other cases you can read more about crontab and the syntax here. You can simulate cron settings using this smart website. Or you can use the Cron expression editor provided underneath the calendar symbol on the right hand side:

Configure your expression with the help of this editor. The Next trigger times at the top helps to visualize the configured expression. Press OK towards the end of this editor window to store the given values.

Polling timeout​

The Polling timeout [sec] defines the time in seconds to wait until a polling request fails. Depending on the endpoint and its responsiveness you may want to change this number to something higher or lower. You should set it high enough, so that you are confident that the endpoint responds under normal operation.

Stable time​

The Stable time [sec] defines the number of seconds that file statistics must stay unchanged for considering it as stable. Configuring a value in here will check the appropriate file stability before processing the file.

Ordering​

When listing objects from the source for processing, you can define in what order they should be processed. Pick one of the following self-explanatory settings:

  • Alphabetically, ascending
  • Alphabetically, descending
  • Last modified, ascending
  • Last modified, descending

Reprocessing mode​

Configuring the Reprocessing mode relates to layline.io's Access Coordinator feature. You can pick between three modes:

  • Manual access coordinator reset: any source element processed and stored in layline.io's history needs manual reset within the Sources Coordinator before reprocessing of a re-ingested source is performed (default mode).
  • Automatic access coordinator reset: this mode allows the automatc reprocessig of already processed and re-ingested sources as soon as the respective input source has been moved into the configured done or error directory.
  • When input changed: this mode behaves as described in Manual access coordinator reset while it performs an additional check whether the source has potentially changed; i.e. the name of the source is identical but the content differs. In case the input in fact changed, the reprocessing will start without manual intervention.

Wait for processing clearance​

Activating this checkbox identifies new input sources as Wait for processing clearance. This means, the input source leaves unprocessed in the input directory until a) a manual intervention through Operations provides active clearance for processing the respective file or b) some Javascript executes the AccessCoordinator.giveClearance(source: string, stream: string, timeout?: number) method.

Email Settings​

Configure the parameters for your Email endpoint:

Setting (Email Source)

Connection​

Email Connection drop-down list

Use the drop-down list to select an Email Connection that should support this Email configuration. If it does not exist, you need to create it first.

info

Your Email Connection needs to have the following configured scope:

  • mail.readwrite

Stream name​

By its nature, an Email Source does not appear with a classical stream name. At this point you define the stream name for later identification during processing within a workflow:

  • Stream name : name to apply for the email workflow stream processing

You need to ensure that the name is unique. As you can see from the example above, you can use Macros here. In the above case we chose to include several constants like subject: / from: / received: etc. In addition, we included several classical email identification elements deducted from Macros to form the email stream name. Finally, the Audit trail for data processed through the configured Email source will look similar to a classical email inbox folder:

Folders​

  • Input folder : The directory to read emails from. The configured input folder must be accessible to the Reactive Engine trying to access the Email source. You can use ${...} macros to expand variables defined in environment variables.

  • Done folder : The directory to which emails are moved when fully processed. Leaving it empty, the emails will not be moved. The configured done folder must be accessible to the Reactive Engine trying to access the Email source. You can use ${...} macros to expand variables defined in environment variables.

  • Error folder : The directory to which emails are moved in case of a problem with the email during processing. Leaving it empty, the emails will not be moved. The configured error folder must be accessible to the Reactive Engine trying to access the Email source. You can use ${...} macros to expand variables defined in environment variables.

  • Ignore folder : The directory to which emails are moved in case they are configured to be ignored in the Ignore emails section (see next). Leaving it empty, the emails will not be moved. The configured ignore folder must be accessible to the Reactive Engine trying to access the Email source. You can use ${...} macros to expand variables defined in environment variables.

A final configuration could look like this:

Ignore Emails​

By default, all emails arriving in the configured Input folder will be processed. Though it is possible to define which emails are not relevant (Blacklist) resp. explicitly relevant (Whitelist) for processing by activating the Ignore Emails checkbox.

  • From filter : Blacklist resp. Whitelist definitions to apply towards email sender values
  • Subject filter : Blacklist resp. Whitelist definitions to apply towards the email subject values

Regular expression values can be configured by pushing the respective + ADD TO BLACKLIST resp. + ADD TO WHITELIST button. Logically layline.io will check any configured blacklist configuration first and evaluate any whitelist configuration afterwards.

In case any Blacklist expression is matching an incoming email, the email will be ignored. Having configured an Ignore folder, that specific email will be moved towards that folder. Otherwise, the email remains unprocessed in the Input folder.

Any incoming email matching the Whitelist expression will lead to processing that email and moving it into the Done folder or the Error folder afterwards. In case no specific folder is configured the email will remain in the Input folder.

  • If you configure only Whitelist expressions, this will implicitly mark all others to be ignored

  • If you configure only Blacklist expressions, this will implicitly define all others to be processed

  • Configuring a combination of both (i.e. whitelist AND blacklist have at least one entry each!), it is important to understand the following:

The order of expression evaluation will always be:

  1. First Step: Ignore emails matching blacklist
  2. Second Step: Process emails matching whitelist
  3. Third Step: Ignore emails not falling in any category

Attachments settings​

By default, attachments to emails are not loaded. Though it is possible to allow attachment loading by activating the Load attachments checkbox and configure the details:

  • Maximum size of all loaded attachments [kb] : limit the overall size of attachments per processed email to not overload your system capacity (value configured in kb)

  • Mime type filter : filter conditions to further restrict the loading based on type of attachment and / or size:

    • Blacklist :

      • Mime type regular expression : similar as explained above, a regular expression for type of attachments that should be ignored (e.g. 'application/.*' to exclude all attachments of ' application'-related mime types)
      • Size constraints [kb] : optional parameter that could be used to exclude only those type of attachments with a size greater than the configure size value; no configured value will ignore this parameter

    • Whitelist :

      • Mime type regular expression : similar as explained above, a regular expression for type of attachments that should be included for processing (e.g. 'application/.*' to include only attachments of 'application'-related mime types)
      • Size constraints [kb] : optional parameter that could be used to include only those type of attachments with a size less or equal than the configure size value; no configured value will ignore this parameter. Please note that the configured maximum size takes precedence in the overall setup!

  • If you configure only Whitelist expressions, this will implicitly mark all others to be ignored

  • If you configure only Blacklist expressions, this will implicitly define all others to be processed

  • Configuring a combination of both (i.e. whitelist AND blacklist have at least one entry each!), it is important to understand the following:

The order of expression evaluation will always be:

  1. First Step: Ignore emails matching blacklist
  2. Second Step: Process emails matching whitelist
  3. Third Step: Ignore emails not falling in any category
Can't find what you are looking for?

Please note, that the creation of the online documentation is Work-In-Progress. It is constantly being updated. should you have questions or suggestions, please don't hesitate to contact us at support@layline.io .