Am I using switch/case wrong here to control? - switch-statement

I am trying to check the logs and depending the last log, run a different step in the transformation. Am I supposed to use some other steps or am I making another mistake here?
For example, if the query returns 1 I want execute SQL script to run, for 2 I want execute SQL script 2 to run and for 3 I want transformation to abort. But it keeps running all the steps even if only one value returns from the CONTROL step.
The transformation looks like this
And the switch/case step looks like this

It looks like it's correctly configured, but keep in mind that in a transformation all steps are initiated at the beginning of the transformation, waiting to receive the streaming data from the previous step. So the Abort and Execute script steps are going to be started as soon as the transformation is started, if they don't need data from the previous step to run, they are going to run at the beginning.
If you want the scripts to be executed depending on the result of the CONTROL output, you'll need to use a job, that runs the steps (actions) sequencially:
A transformation runs the CONTROL step and afterwards you put a "Copy rows to result" step to make the data produced from the CONTROL step available to the job
After the transformation, you use a "Simple evaluation" action in the job, to determine which script (or abort) to run. Jobs also have an "Execute SQL Script" action, so you can put it afterwards.
I'm supposing your CONTROL step only produces one row, if the output is more than one row, the "Simple evaluation" action won't do the job, you'll have to design one of various transformations to execute for each row of the previous transformation, running what you need.

Related

Databricks Notebook Command Status Handshake with ADF

I have an ADF pipeline which has around 30 activities that call Databricks Notebooks. The activities are arranged sequentially, that is, one gets executed only after the successful completion of the other.
However, at times, even when there is a run time error with a particular notebook, the activity that calls the notebook is not failing, and the next activity is triggered. Ideally, this should not happen.
So, I want to keep an additional check on the link condition between the activities. I plan to put a condition on the status of the commands running in the notebook (imagine a notebook has 10 python commands, I want to capture the status of 10th command).
Is there a way to configure this? Appreciate ideas. Thank you.
I did try at my end - When there was an exception in the code - I did see the output of the error in the activity output. But in my case the activity failed like #Alex mentioned.
In your case you could check the output of the activity and see whether there is any run error. If there is no runError, then proceed with the next activity.
#activity('Notebook2').output.runError

Azure data factory IF condition is taking a lot longer to complete than the activities inside it take to complete

Ok guys, this is a strange one and I can't see anything obvious that would explain it...
I've got a pipeline with an IF condition, this IF condition only has a single 'copy data' activity in it. My confusion is that when monitoring this pipeline as its been triggered by a scheduled trigger, the IF condition often takes a lot longer than the only activity, the 'copy data' activity, that it contains. See screen shot below, where the 'copy data' has only taken 7:47mins but the IF condition has a duration of 16:16mins!?!?!
Does anyone know what this means, and what might be causing it? Note... the IF condition itself is only a simple check of a variable that has previously been set before...
At first I thought it was because the 'copy data' was queueing, but as there's no input/output information on an IF condition in the monitor I've no idea what's going on. Surely the IF condition isn't taking several minutes to evaluate its expression??
When you read the "Duration" time, that it is end-to-end for the pipeline activity. That takes into account all factors like marshaling of your data flow script from ADF to the Spark cluster, cluster acquisition time, job execution, and I/O write time. So the "Duration" time will be longer than actual execution time.
Therefore, the IF conditional activity is waiting for the response from the copy activity successfully ended and close all diu resources. But there is very little official information about this explanation.:(
By the way, the "Duration" time of the IF condition activity is not chargeable. You can click this link to see run consumption.
IF condition activity is is billed according to runs at first line. The copy activity is billed according to diu. So we don't need to worry about the "Duration" time of the IF condition activity. :)

How to acces output folder from a PythonScriptStep?

I'm new to azure-ml, and have been tasked to make some integration tests for a couple of pipeline steps. I have prepared some input test data and some expected output data, which I store on a 'test_datastore'. The following example code is a simplified version of what I want to do:
ws = Workspace.from_config('blabla/config.json')
ds = Datastore.get(ws, datastore_name='test_datastore')
main_ref = DataReference(datastore=ds,
data_reference_name='main_ref'
)
data_ref = DataReference(datastore=ds,
data_reference_name='main_ref',
path_on_datastore='/data'
)
data_prep_step = PythonScriptStep(
name='data_prep',
script_name='pipeline_steps/data_prep.py',
source_directory='/.',
arguments=['--main_path', main_ref,
'--data_ref_folder', data_ref
],
inputs=[main_ref, data_ref],
outputs=[data_ref],
runconfig=arbitrary_run_config,
allow_reuse=False
)
I would like:
my data_prep_step to run,
have it store some data on the path to my data_ref), and
I would then like to access this stored data afterwards outside of the pipeline
But, I can't find a useful function in the documentation. Any guidance would be much appreciated.
two big ideas here -- let's start with the main one.
main ask
With an Azure ML Pipeline, how can I access the output data of a PythonScriptStep outside of the context of the pipeline?
short answer
Consider using OutputFileDatasetConfig (docs example), instead of DataReference.
To your example above, I would just change your last two definitions.
data_ref = OutputFileDatasetConfig(
name='data_ref',
destination=(ds, '/data')
).as_upload()
data_prep_step = PythonScriptStep(
name='data_prep',
script_name='pipeline_steps/data_prep.py',
source_directory='/.',
arguments=[
'--main_path', main_ref,
'--data_ref_folder', data_ref
],
inputs=[main_ref, data_ref],
outputs=[data_ref],
runconfig=arbitrary_run_config,
allow_reuse=False
)
some notes:
be sure to check out how DataPaths work. Can be tricky at first glance.
set overwrite=False in the `.as_upload() method if you don't want future runs to overwrite the first run's data.
more context
PipelineData used to be the defacto object to pass data ephemerally between pipeline steps. The idea was to make it easy to:
stitch steps together
get the data after the pipeline runs if need be (datastore/azureml/{run_id}/data_ref)
The downside was that you have no control over where the pipeline is saved. If you wanted to data for more than just as a baton that gets passed between steps, you could have a DataTransferStep to land the PipelineData wherever you please after the PythonScriptStep finishes.
This downside is what motivated OutputFileDatasetConfig
auxilary ask
how might I programmatically test the functionality of my Azure ML pipeline?
there are not enough people talking about data pipeline testing, IMHO.
There are three areas of data pipeline testing:
unit testing (the code in the step works?
integration testing (the code works when submitted to the Azure ML service)
data expectation testing (the data coming out of the meets my expectations)
For #1, I think it should be done outside of the pipeline perhaps as part of a package of helper functions
For #2, Why not just see if the whole pipeline completes, I think get more information that way. That's how we run our CI.
#3 is the juiciest, and we do this in our pipelines with the Great Expectations (GE) Python library. The GE community calls these "expectation tests". To me you have two options for including expectation tests in your Azure ML pipeline:
within the PythonScriptStep itself, i.e.
run whatever code you have
test the outputs with GE before writing them out; or,
for each functional PythonScriptStep, hang a downstream PythonScriptStep off of it in which you run your expectations against the output data.
Our team does #1, but either strategy should work. What's great about this approach is that you can run your expectation tests by just running your pipeline (which also makes integration testing easy).

JCL should read internal reader than completely submit outer JCL

I have a batch job that has 10 steps in STEP5. I have written an internal JCL and I want after Internal reader step are completed successfully my next step in the parent job which is STEP06 to execute. Could you please give any resolution to this problem.
For what you have described, there are 2 approaches:
Break your process into 3 jobs - steps 1-5 as one job, the second
job consisting of the JCL submitted in sep 5 and the third job
consisting of step 6 (or steps 6-10 - you do not make it clear if
the main JCL has 6 steps and the 'inner' JCL 4 steps, making the 10
steps you mention, or if the main JCL has 10 steps).
The execution of the 3 jobs will need to be serialised somehow.
Simply have the 'inner' JCL as a series of steps in the 'outer' JCL
so that you only have once job with steps that run in order.
The typical approach to this sort of issue would be to use scheduler to handle the 3 part process as 3 jobs the middle one perhaps not submitted by the scheduler but monitored/tracked by it.
With a good scheduler setup, there is a good chance that even if the jobs were run on different machines or even different types of machines that they could be tracked.
To have a single job delayed halfway through is possible but would require some sort of program to run in a loop (waiting so as not to use excessive cpu) checking for an event (a dataset being created or deleted, the job could itself could be checked or numerous other ways).
Another way could be to have part 1 submit a job to do part 2 and that job to then submit another as part 3.
Yet another way, perhaps frowned upon depedning upon it's importance, would be to have three jobs the first part submitted to run, the third part submitted but on hold. The first submits the second which releases the third.
Of course there is also the possibility that one job could do everthing as a single job.

How to re-try an ADF pipeline execution until conditions are met

An ADF pipeline needs to be executed on a daily basis, lets say at 03:00 h AM.
But prior execution we also need to check if the data sources are available.
Data is provided by an external agent, it periodically loads the corresponding data into each source table and let us know when this process is completed using a flag-table: if data source 1 is ready it set flag to 1.
I don't find a way to implement this logic with ADF.
We would need something that, for instance, at 03.00 h would trigger an 'element' that checks the flags, if the flags are not up don't launch the pipeline. Past, lets say, 10 minutes, check again the flags, and be like this for at most X times OR until the flags are up.
If the flags are up, launch the pipeline execution and stop trying to launch the pipeline any further.
How would you do it?
The logic per se is not complicated in any way, but I wouldn't know where to implement it. Should I develop an Azure Funtions that launches the Pipeline or is there a way to achieve it with an out-of-the-box AZDF activity?
There is a UNTIL iteration activity where you can check if your clause.
Example:
Your azure function (AF) checking the flag and returns 0 or 1.
Build ADF pipeline with UNTIL activity where you check the output of AF (if its 1 do something). In UNTIL activity you can have your process step. For example, you have a variable flag that will before until activity is 0. In your until you check if it's 1. if it is do your processing step, if its not, put WAIT activity on 10 min or so.
So you have the ability in ADF to iterate until something it's not satisfied.
Hope that this will help you :)

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