Azure Data factory, How to incrementally copy blob data to sql - azure-data-factory

I have a azure blob container where some json files with data gets put every 6 hours and I want to use Azure Data Factory to copy it to an Azure SQL DB. The file pattern for the files are like this: "customer_year_month_day_hour_min_sec.json.data.json"
The blob container also has other json data files as well so I have filter for the files in the dataset.
First question is how can I set the file path on the blob dataset to only look for the json files that I want? I tried with the wildcard *.data.json but that doesn't work. The only filename wildcard I have gotten to work is *.json
Second question is how can I copy data only from the new files (with the specific file pattern) that lands in the blob storage to Azure SQL? I have no control of the process that puts the data in the blob container and cannot move the files to another location which makes it harder.
Please help.

You could use ADF event trigger to achieve this.
Define your event trigger as 'blob created' and specify the blobPathBeginsWith and blobPathEndsWith property based on your filename pattern.
For the first question, when an event trigger fires for a specific blob, the event captures the folder path and file name of the blob into the properties #triggerBody().folderPath and #triggerBody().fileName. You need to map the properties to pipeline parameters and pass #pipeline.parameters.parameterName expression to your fileName in copy activity.
This also answers the second question, each time the trigger is fired, you'll get the fileName of the newest created files in #triggerBody().folderPath and #triggerBody().fileName.
Thanks.

I understand your situation. Seems they've used a new platform to recreate a decades old problem. :)
The patter I would setup first looks something like:
Create a Storage Account Trigger that will fire on every new file in the source container.
In the triggered Pipeline, examine the blog name to see if it fits your parameters. If no, just end, taking no action. If so, binary copy the blob to a account/container your app owns, leaving the original in place.
Create another Trigger on your container that runs the import Pipeline.
Run your import process.
Couple caveats your management has to understand. You can be very, very reliable, but cannot guarantee compliance because there is no transaction/contract between you and the source container. Also, there may be a sequence gap since a small file can usually process while a larger file is processing.
If for any reason you do miss a file, all you need to do is copy it to your container where your process will pick it up. You can load all previous blobs in the same way.

Related

Azure Data Factory - run script on parquet files and output as parquet files

In Azure Data Factory I have a pipeline, created from the built-in copy data task, that copies data from 12 entities (campaign, lead, contact etc.) from Dynamics CRM (using a linked service) and outputs the contents as parquet files in account storage. This is run every day, into a folder structure based on the date. The output structure in the container looks something like this:
Raw/CRM/2022/05/28/campaign.parquet
Raw/CRM/2022/05/28/lead.parquet
Raw/CRM/2022/05/29/campaign.parquet
Raw/CRM/2022/05/29/lead.parquet
That's just an example, but there is a folder structure for every year/month/day that the pipeline runs, and a parquet file for each of the 12 entities I'm retrieving.
This involved creating a pipeline, dataset for the source and dataset for the target. I modified the pipeline to add the pipeline's run date/time as a column in the parquet files, called RowStartDate (which I'll need in the next stage of processing)
My next step is to process the data into a staging area, which I'd like to output to a different folder in my container. My plan was to create 12 scripts (one for campaigns, one for leads, one for contact etc.) that essentially does the following:
accesses all of the correct files, using a wildcard path along the lines of: Raw/CRM/ * / * / * /campaign.parquet
selects the columns that I need
Rename column headings
in some cases, just take the most recent data (using the RowStartDate)
in some cases, create a slowly changing dimension, ensuring every row has a RowEndDate
I made some progress figuring out how to do this in SQL, by running a query using OPENROWSET with wildcards in the path as per above - but I don't think I can use my SQL script in ADF to move/process the data into a separate folder in my container.
My question is, how can I do this (preferably in ADF pipelines):
for each of my 12 entities, access each occurrence in the container with some sort of Raw/CRM///*/campaign.parquet statement
Process it as per the logic I've described above - a script of some sort
Output the contents back to a different folder in my container (each script would produce 1 output)
I've tried:
Using Azure Data Factory, but when I tell it which dataset to use, I point it to the dataset I created in my original pipeline - but this dataset has all 12 entities in the dataset and the data flow activity produces the error: "No value provided for Parameter 'cw_fileName" - but I don't see any place when configuring the data flow to specify a parameter (its not under source settings, source options, projection, optimize or inspect)
using Azure Data Factory, tried to add a script - but in trying to connect to my SQL script in Synapse - I don't know my Service Principal Key for the synapse workspace
using a notebook Databricks, I tried to mount my container but got an error along the lines that "adding secret to Databricks scope doesn't work in Standard Tier" so couldn't proceed
using Synapse, but as expected, it wants things in SQL whereas I'm trying to keep things in a container for now.
Could anybody point me in the right direction. What's the best approach that I should take? And if its one that I've described above, how do I go about getting past the issue I've described?
Pass the data flow dataset parameter values from the pipeline data flow activity settings.

How can I pass output from a filter activity directly to a copy activity in ADF?

I have 4000 files each averaging 30Kb in size landing in a folder on our on premise file system each day. I want to apply conditional logic (several and/or conditions) against details in their file names to only move files matching the conditions into another folder. I have tried linking a meta data activity which gets all files in the source folder with a filter activity which applies the conditional logic with a for each activity with an embedded copy activity. This works but it is taking hours to process the files. When running the pipeline in debug the output window appears to list each file copied as a line item. I’ve increased the batch count setting in the for each to 50 but it hasn’t improved things. Is there a way to link the filter activity directly to the copy activity without using for each activity? Ie pass the collection from the filter straight into copy’s source. Alternatively, some of our other pipelines just use the copy activity pointing to a source folder and we configure its filefilter setting with a simple regex using a combination of * and ?, which is extremely fast. However, in this particular scenario, my conditional logic is more complex and I need to compare attributes in each file’s name with values to decide if the file should be moved. The filefilter setting allows dynamic content so I could remove the filter activity completely, point the copy to the source folder and put the conditional logic in the filefilter’s dynamic content area but how would I get a reference to the file name to do the conditional checks?
Here is one solution:
Write array output as text to a .json in Blob Storage (or wherever). Here are the steps to make that work:
Copy Data Source:
Copy Data Sink:
Write the json (array output) to a text file that has the name of the files you want to copy.
Copy Activity Source (to get it from JSON to .txt):
Sink will be .txt file in your Blob.
Use that text file in your main copy activity and use the following setting:
This should copy over all the files that you identified in your Filter Activity.
I realize this is a work around, but really is the only solution for what you are asking. Otherwise there is no way to link a filter activity straight to a copy activity.

Is it possible to merge Azure Data Factory data flows

I have two separate Data flows in Azure Data Factory, and I want to combine them into a single Data flow.
There is a technique for copying elements from one Data flow to another, as described in this video: https://www.youtube.com/watch?v=3_1I4XdoBKQ
This does not work for Source or Sink stages, though. The Script elements do not contain the Dataset that the Source or Sink is connected to, and if you try to copy them, the designer window closes and the Data flow is corrupted. The details are in the JSON, but I have tried copying and pasting into the JSON and that doesn't work either - the source appears on the canvas, but is not usable.
Does anyone know if there is a technique for doing this, other than just manually recreating the objects on the canvas?
Thanks Leon for confirming that this isn't supported, here is my workaround process.
Open the Data Flow that will receive the merged code.
Open the Data Flow that contains the code to merge in.
Go through the to-be-merged flow and change the names of any transformations that clash with the names of transformations in the target flow.
Manually create, in the target flow, any Sources that did not already exist.
Copy the entire script out of the to-be-merged flow into a text editor.
Remove the Sources and Sinks.
Copy the remaining transformations into the clipboard, and paste them in to the target flow's script editor.
Manually create the Sinks, remembering to set all properties such as "Allow Update".
Be prepared that, if you make a mistake and paste in something that is not correct, then the flow editor window will close and the flow will be unusable. The only way to recover it is to refresh and discard all changes since you last published, so don't do this if you have other unpublished changes that you don't want to lose!
I have already established a practice in our team that no mappings are done in Sinks. All mappings are done in Derived Column transformations, and any column name ambiguity is resolved in a Select transformations, so the Sink is always just auto-map. That makes operations like this simpler.
It should be possible to keep the Source definitions in Step 6, remove the Source elements from the target script, and paste the new Sources in to replace them, but that's a little more complex and error-prone.

is it possible to copy only the first few bytes of a file?

I have a copy activity where the source is sftp and the sink is blob storage.
Is it possible to ONLY copy the first few hundred bytes of a file?
I see the answer for your another SO thread how to output variable to a file?, its solution is also suitable for the current scenario to return the first few hundred bytes of a file in Azure Functions to Copy Activity.
If you don't want to use this way, I think the only solution is to follow the offical document Use custom activities in an Azure Data Factory pipeline to create a custom activity in programming to realize the feature you want.

Logic App Blob Trigger for a group of blobs

I'm creating a Logic App that has to process all blobs that in a certain container. I would like to periodically check whether there are any new blobs and, if yes, start a run. I tried using the "When a blob is added or modified". However, if at the time of checking there are several new blobs, several new runs are initiated. Is there a way to only initiate one run if one or more blobs are added/modified?
I experimented with the "Number of blobs to return from the trigger" and also with the split-on setting, but I haven't found a way yet.
If you want to trigger with multiple blob files, yes you have to use When a blob is added or modified. From the connector description you could know
This operation triggers a flow when one or more blobs are added or modified in a container.
And you must set the maxFileCount also you already find the result is split into separate parts. This is because the default setting the splitOn is on, if you want the result be a whole you need to set it OFF.
The the result should be what you want.