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Author's profile photo Mandy Krimmel

Cloud Integration – Use Poll-Enrich with SFTP Adapter

This blog describes how to configure the new Poll Enrich pattern in combination with the sftp adapter, elaborating on use cases and different configuration options.

Use Poll Enrich with SFTP Adapter

In general, there are three main use cases for the Poll Enrich pattern:

  • You want to enrich the message payload with additional data retrieved from a file on the sftp server.
  • You want to poll from an sftp server triggered by an external trigger, for example triggered via HTTP call.
  • You need to poll from an sftp server but want to define the configuration in the sftp adapter dynamically, for example from a partner directory.

In this blog, I will focus on the second and third use case. Yet, I will shortly also mention the configuration option for the first use case when discussing the integration flow configuration.

This is the simple integration flow we are going to build:

The flow starts with a HTTP inbound adapter that triggers the message processing. In a subsequent Content Modifier, some properties are defined that are used dynamically in the sftp adapter when polling the file from sftp server. At the very end, the message is sent out to the receiver system.

Let’s start.

In the integration flow, draw a connection from the Sender participant to the Start Message event and select the HTTP adapter; then add a Content Modifier next to it. Configure the HTTP adapter as you like.

In the Content Modifier, you define the properties that are to be used dynamically in the SFTP Adapter. For dynamically configurable settings, refer to the blog Cloud Integration – Dynamically Configure the SFTP Receiver Adapter. The same settings are allowed dynamically in the sftp adapter in the Poll-Enrich pattern. Note that with the first increment (version 1.0 of the Poll Enrich sftp adapter), Proxy Type and Authentication can’t yet be set dynamically.

For my simple scenario, I define the following properties to set them dynamically via XPath from the incoming http request:

Next to the Content Modifier, configure the Poll Enrich step. For this, in the Call section of the modeler, select External Call and then Poll Enrich.

In the Poll Enrich step, we have to configure how the payloads need to be aggregated: the one before the Poll Enrich step and the payload fetched from sftp server need. In addition you configure what to do if no message is found on the sftp server.

The aggregation is configured with the help of the Aggregation Algorithm in the Poll Enrich step:

For our use case (to simply read files via external trigger or via dynamic configuration in the sftp adapter), the Replace option is the correct choice. This algorithm simply replaces the original message (payload and headers) before the Poll Enrich step with the new one fetched from the sftp server.

If you want to enrich your original payload (use case 1), you have to select one of the other two algorithms:

  • Combine XML: This option combines the message polled from the sftp server with the original message in multimapping format. This option makes most sense if both, the original and the polled message, are XML messages.
  • Concatenate: The message polled from the sftp server is added to the existing message. This option is useful for strings.

If you want to get an exception in case no message is found on the sftp server you can select the checkbox Throw Exception if no Message Found. If not selected, the header SAP_PollEnrichMessageFound is set to false if no message can be found during processing. Based on the header you can configure alternative processing.

Having defined the Poll Enrich step, we now need to configure the SFTP adapter. To do so, add another Sender participant and draw a connection from this new Sender participant to the Poll Enrich step. Select the SFTP adapter.

The configuration of the SFTP adapter will look familiar to you because it contains almost the same configuration options as the normal SFTP sender adapter. Some configurations, like the Scheduler tab, are missing because they are not relevant in this pattern, but most settings are equal.

In the configuration we specify the properties defined in the Content Modifier:

As a final step, configure a connection to the Receiver participant to send the message out.

Deploy the flow and trigger it with a payload that provides the necessary data; in my example, I use the following simple payload:

<?xml version='1.0' encoding='UTF-8' ?>
<request>
	<sftp>
	<Directory>test/test1</Directory>
        <File>TestFile*</File>
	</sftp>
</request>

Note that in case no file can be found on the sftp server, the processing continues with the payload before the Poll Enrich step. It is planned to offer specific handling in such a case.

I hope this simple scenario helps you to understand the Poll Enrich pattern.

Planned Extensions:

  • Dynamic Configuration of Proxy Type and Authentication (available after the June 2021 update)
  • Keep File and Process Again option not available (available with July 2021 update)
  • Configure Handling if File is not found on the sftp server (available with August 2021 update)
  • Support FTP adapter in Poll Enrich step

 

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      Author's profile photo Federico Bellizia
      Federico Bellizia

      Hi Mandy,

      this is a dream feature we waited from 4 years, thank you very much, could you ask to your developer to add on Process the option None, a lot of time we just need to read files without variation of timestamp and position.

      We tried some workaround like   take file move on processing folder and at end on workflow put it bak on sftp original folder.

       

      Destination folder doesn't accept properties, headers like parameter and if you put  .  instead .archive  it doesn't work, files disappears on void :).

       

      Thank you and good job!

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Hello Federico,

      thank you for your nice feedback.

      Concerning option None you mean to simply keep the file and process it again with the next poll? This will come with the next update, it will be called 'Keep File and Process Again'. Note that you need to recreate the sftp channel to get the new version of the polling sftp sender adapter to get this feature.

      Best regards,

      Mandy

       

      Author's profile photo Federico Bellizia
      Federico Bellizia

       

      As you can see there is no way to keep file for next run....

       

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      As said, this feature will come with the next update only. This is in about 2-3 weeks. Afterwards you will find it 🙂

      Best regards

      Mandy

       

      Author's profile photo Pushkar Patel
      Pushkar Patel

      Hi Mandy Krimmel ,
      With Poll Enrich, when I am trying to use SFTP adapter and post processing as delete, its not working. Is there any limitation around deletion the file after processing with Poll Enrich ?

      Thanks,

      Pushkar

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      This should work, maybe there is a problem with permission to delete the file? Maybe check the log files in the sftp server.

      Best regards

      Mandy

      Author's profile photo monica bhosale
      monica bhosale

      Hi Mandy,

      Thank you for sharing this information, it's really efforts saving functionality in middleware. In omy current development we have FTP server ,any tentative date when we are planning to have this functionality for FTP?

       

      Thank you,

      Monica

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      It is planned for the September or October update, depending how well the testing goes.

      Best regards,

      Mandy

      Author's profile photo monica bhosale
      monica bhosale

      Thank you for quick reply and update Mandy, it's really helpful .Just check roadmap plan and it's in Q3, eagerly waiting for this feature as this will help to reduce lots of customize  efforts in development .

      Author's profile photo Jeremy Ma
      Jeremy Ma

      Hi Mandy,  In this SFTP poll enrich processing option for sorting and polling is missing, when will this be available.  Or is this by design where you have to pass the dir/filename as a variable to poll enrich > ftp?

       

      Thanks

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      This is as per design, the sorting does not work together with the poll-enrich step. Because of this this option is not available. If you need a specific file you need to pass the file name as header/property.

      BR

      Mandy

      Author's profile photo Santhosh ReddyKolanu
      Santhosh ReddyKolanu

      Hi Mandy,

       

      Very useful blog.

      I just want to know the differences between Content enricher via SFTP and Poll enricher. I understand that poll enricher has better aggregation strategies.

      Want to know the other differences reason being poll enricher works for sender and Content enricher works with a receiver. However both of these are actually polling SFTP based on the file name, directory details we configure. They poll the file data and enrich as per aggregation strategy.

      Regards,

      Santosh

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Hello Santosh,

      Content Enricher is always using the response coming back from the receiver to aggregate. It is using a receiver channel. And if you choose a receiver channel you can write files to sftp adapter but not poll files from there. The polling of files in the middle of the flow only works with the poll enricher as this is using a sftp sender channel.

      Content Enricher is usually used with HTTP based adapters that send a response and this response is to be aggregated to the payload.

      Best regards

      Mandy

      Author's profile photo Madina Mendoza
      Madina Mendoza

      Hi Mandy,

       

      Thanks for this. We wanted to check whether the Sender can also be an SFTP? We wanted to be able to process and incoming SFTP file and perform a lookup on another SFTP file using the poll enricher.

       

      Thanks.

       

      Regards,

      Madina

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Yes, this is possible.

      BR

      Mandy

      Author's profile photo Madina Mendoza
      Madina Mendoza

      Thanks, Mandy! Indeed the CPI Consultant confirmed this.

       

      Cheers,

      Madina

      Author's profile photo Erigella NaveenReddy
      Erigella NaveenReddy

      Hi Mandy,

      Poll enrich will poll all the files and combine the all files data which are available in Sftp with original message or only single file data will combine with original message?

       

      Thanks,

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      It will poll only one file at one execution.

      BR

      Mandy

      Author's profile photo Stefan Grünert
      Stefan Grünert

      Hi Mandy,

      so if it only polls one file from a directory (even if there are more files) and my requirement is, to leave all files untouched after reading, how can I achieve to read all the other files?

      Regards
      Stefan

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Hello Stefan,

      if you want to not touch the file in the sftp server you may use the post-processing option to mark the file in Idempotent Repository. With this the file is not polled anymore even if not moved or deleted on the sftp server.

      Or do I not understand the scenario correctly and you even want to poll the files again in a subsequent processing?

      Regards

      Mandy

       

      Author's profile photo Stefan Grünert
      Stefan Grünert

      Hi Mandy,

      thank you for your reply. With the post-processing option it should work for me.
      The files on the sftp server won't be deleted, but every week they will be replaced, meaning, the names of the files won't change, only their file-data. But I assume once marked and then replaced I can mark the files the following week again?

      Regards
      Stefan

      Author's profile photo Sunitha Mamidi
      Sunitha Mamidi

      Hi Mandy,

      I have to pick files from the SFTP folder in the format ABC20211207.txt

      I have tried to give regular expression as - ABC[0-9]{8}\.txt, ABC*.txt, ABC.*\.txt. But the file is not getting picked no matter what regular expression I give. Can you please let me know what can I give in the File name to pick the files in the above format.

      Appreciate your help,

      Sunitha Mamidi

       

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Hello,

      please refer to Configure the SFTP Sender Adapter Used with the Poll Enrich Step - SAP Help Portal.

      ABC*.txt should work, the others not.

      Best regards

      Mandy

      Author's profile photo Sunitha Mamidi
      Sunitha Mamidi

      Hi Mandy,

      Thank you for your quick response.

      If I give this regular expression (ABC*.txt), The file is getting picked.

      But when I select the option in processing tab, Read Lock Strategy --> Done File Expected (As per our requirement). The file is not getting picked. What is causing the issue?

      Thank you,

      Sunitha

       

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Hi Sunitha,

      how did you define the done file?

      Best regards

      Mandy

      Author's profile photo Sunitha Mamidi
      Sunitha Mamidi

      Hi Mandy,

      Thank you for your time.

      We have 2 IFlows for this scenario -

      1. Create the file in SFTP Folder - We pull the records from SucessFactor based on some filter condition and create a .txt file in SFTP folder. Since this is a huge load we have implemented pagination. Once the pagination is complete, We are writing a .done file in the same folder, to indicate the file to be processed is ready to send to Vendor.
      2. Transfer the file to the Vendor  - We have to schedule the interface to run on every 1st and 3rd Friday. So here we need to check that the .done file is available only then transfer the file to vendor. Because .done file indicates that it is the complete load.

      The .done file is available in the SFTP folder for my scenario. If I select this option and give the regular expression as above, The file is not getting picked.

      Regards,

      Sunitha

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Hello Sunitha,

      we currently have an issue with the dynamic done file setting. We are working on a fix for this.

      Could you please try the following as a workaround:

      • set the expression you have set for the done file to a property in a content modifier step before the adapter call
      • in the sftp channel specify the property via ${property.<propertyName>}

      Please let my know if this workaround solves your issue.

      Best regards

      Mandy

      Author's profile photo Sunitha Mamidi
      Sunitha Mamidi

      Hi Mandy,

      The workaround solved my issue.

      Thank you so much for your valuable time.

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      thank you for the info. Glad it solved your issue.

      Author's profile photo Gunnar Lehker
      Gunnar Lehker

      Hi Mandy,

      thanks for your useful blogpost!

      How can I get the filename from the sftp server? Neither the sftp nor the poll enrich adapter provides such a property or am I missing a detail?

      BR, Gunnar

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      CamelFileName is the header that is set be the adapter to give the filename. Please check this in trace. You may have to set the header in the Allowed Headers Configuration in the integration flow configuration.

      Best regards

      Mandy

      Author's profile photo david huber
      david huber

      Hi Mandy,

      Thanks for this blog 🙂 can you please help me on my current scenario that after reading the file i need to catch the file content for encode this to base64 ?. Is it this possible to do it ?.

      Can you please help me with an example if you have ?.

      Thanks

      Best regards.

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      I dont fully understand your requirement. If the file is polled via poll-enrich the file content is available in the exchange and can be processed for example via the base64 encoder to convert the payload to base64 format.

      Best regards

      Mandy

      Author's profile photo Ramana Reddy Reddy Moole
      Ramana Reddy Reddy Moole

      Hi Mandy,

      Great article. But I need to read all the files in the SFTP folder. I am trying to use pollEnrich with SFTP sender with CombinedXML option. It seems like not working. I am seeing only one file content in the log. Please let me know if you have any suggestions.

      Best Regards
      Ramana Reddy

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Poll-Enrich always only fetches one file. If you want to fetch multiple files you need to call the sftp in Poll-Enrich in a loop.

      Best regards

      Mandy

      Author's profile photo Ramana Reddy Reddy Moole
      Ramana Reddy Reddy Moole

      Thank you Mandy Krimmel. Is there any approach to get the count of the files from SFTP to loop those many number of times to get all the files. Sorry I am new to CPI.

      Best Regards
      Ramana Reddy

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      No, unfortunately there is no option to get the count. It would probably be best to loop as long as there are files returned and stop if no file is retrieved anymore.

      Please note, currently there is an issue with the sftp poll-enrich and the post-processing. Please use the loop in one flow and from the loop process call the poll-enrich in another flow connected via ProcessDirect adapter. This solves the issue with the not working post-processing as the flow called via Process Direct is executing the post-processing per file.

      Best regards

      Mandy

      Author's profile photo Ramana Reddy Reddy Moole
      Ramana Reddy Reddy Moole

      Thank you Mandy Krimmel . Please correct if my understanding is correct?

      Main Flow -> Process Call -> ProcessDirect Adapter -> PollEnrich with SFTP

       

      Best Regards

      Ramana Reddy

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      correct

      Author's profile photo Shameer Shaik
      Shameer Shaik

      Hi Mandy Krimmel,

      Please note, currently there is an issue with the sftp poll-enrich and the post-processing. ---Is this issue fixed in the new patch

       

      Ramana Reddy Reddy Moole

      Did the workaround solved your issue.

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      The discussions about how to solve them are still ongoing. It is unfortunately not so easy. You should still use the workaround as described above.

      Best regards

      Mandy

      Author's profile photo Stefan Grünert
      Stefan Grünert

      Hi Mandy,

      I was wondering when the Poll Enrich step will support the FTP adapter? 

      Because I am having trouble using FTP adapter currently connected to the start message as it won't let me use the date variable or properties as it is right at the start. I need to access directories depending on the current date.

      Thank you for the support in here!

      Best regards
      Stefan

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      As there were still some improvements in the Poll-Enrich step required, we had to move the support for FTP adapter to a later time. As soon as we sort out the current issues we will enhance it with the FTP Adapter. But this will be earliest in Q3 2022.

      Best regards

      Mandy

      Author's profile photo Stefan Grünert
      Stefan Grünert

      Thank you for the answer.

      So, in general, there is no way yet to dynamically get files for FTP except when using scripts?

      Best regards
      Stefan

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      This is correct, script is currently the only option. Once we have the ftp adapter in Poll-enrich this will be possible.

      Best regards,

      Mandy

      Author's profile photo Fellipe Mendes
      Fellipe Mendes

      Hello Mandy, nice blog! Congrats!
      Could you please clarify if there are several files in the directory to be read how is the behaivor of the adapter?

      I tried with two files in the same directory and only one of them was read.

       

      Thank you!

      Fellipe

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      This is correct, Poll-Enrich always only polls one file. If you need to poll multiple file you need to do this Poll-Enrich call in a loop.

      Best regards

      Mandy

      Author's profile photo Fellipe Mendes
      Fellipe Mendes

      Hello Mandy!
      Thank you for your attention and quick response.

      I tried to implement the Poll-Enrich call in a loop, the first time, a file is read (SAP_PollEnrichMessageFound = true), however, in the second time, the file is not read (SAP_PollEnrichMessageFound = false).

      Do I need to clear something (property, header, etc) after the first read?

       

      Thank you!

      Fellipe

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Hello Felipe,

      usually this should work.

      I remember that there is/was an issue with the sftp poll-enrich and the post-processing in a loop. Please try to use the loop in one integration flow and from the loop process call the second flow via processDirect adapter. The second flow then contains the poll-enrich with sftp.

      Main Flow -> Loop Process Call -> ProcessDirect Adapter -> Second Flow with PollEnrich with SFTP

      This solves the issue with the not working post-processing as the flow called via Process Direct is executing the post-processing per file.

      Please let me know if this works for you.

      Best regards

      Mandy

      Author's profile photo Fellipe Mendes
      Fellipe Mendes

      Hello Mandy.

       

      Thank you for your recomendation. It worked in this way.

       

      It's important to say that is not possible to transfer all Headers (set * in the Runtime Configuration - Allowed Header(s)) to the Second Flow. It looks like there is some problem with headers populated from the previous round. At least that's what I realized.

       

      Best regards.

       

      Fellipe

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Hello,

      some internal or adapter specific headers are not transported, this is correct.

      Best regards

      Mandy

      Author's profile photo Fellipe Mendes
      Fellipe Mendes

      Hello Mandy.

      Thanks for the answer, what I meant is that if you transfer all headers (with *), the second pooling doesn't work, because the headers are transfered with "dirt" from the previous run.

      I believe this is also what happens when you run two (or more) pools within the same iFlow (by loop).

      It might be interesting to think about creating a parameter in the Pool enrich function allowing you to configure it to clear the headers to perform the second (and nexts) pooling.

       

      Best regards

      Fellipe

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      ok, thank you for this details, will forward this information to the developers.

      Best regards

      Mandy

      Author's profile photo Yeswanth Posam
      Yeswanth Posam

      Hi Mandy,

      I am unable to fetch file using process direct and poll enrich step.

      Flow :- Main flow(JMS Sender --> Process Direct)-->2nd flow(Process Direct-->Poll Enrich(pickfile and delete))

      Log from Adapter Monitoring which shows the correct filename but file is not picked and replaced with input data using Poll Enrich step.

      sap-sftp://virtualSFTP:450/Desktop/SFTP_SRC?authMethod=user&autoCreate=false&connectTimeout=10000&connectivityServiceProvider=%23connectivityServiceProvider&credential=SFTP_USER&delete=true&disconnect=true&fileNameFilter=TestS1.xml&inProgressRepositoryFactory=%23inProgressRepositoryFactory&initialDelay=0&keyStoreAccess=%23keyStoreAccess&knownHostsAccess=%23knownHostsAccess&maxMessagesPerPoll=1&maximumReconnectAttempts=3&noop=false&passwordStorage=%23secureStore&pdUri=&proxyType=onPremise&readLock=none&reconnectDelay=1000&recursive=false&soTimeout=300000&startingDirectoryMustExist=true&stepwise=false&streamDownload=false&synchronous=true&throwExceptionOnConnectFailed=true

       

      Regards,

      Sachin Belide

       

       

       

       

       

       

      Author's profile photo Mandy Krimmel
      Mandy Krimmel
      Blog Post Author

      Hello,

      I would suggest to open a ticket on LOD-HCI-PI-CON-SOAP so that the experts can check the issue in more detail. Its hard to do troubleshooting without any details. Please attach the message processing logs and the two integration flows to the ticket.

      Best regards

      Mandy

      Author's profile photo Yeswanth Posam
      Yeswanth Posam

      Hi Mandy,

      Thankyou for the quick response.

      This scenario did not work in trial tenant. I have imported the same flows in Dev account and it worked.

       

      Regards,

      Sachin Belide