block until done tool problem

[BK_OPTUS]

Hi, 

I am using the block until done tool in Alteryx to output data in two different tabs in an excel file. 

It appears that data is coming into the input anchor and is not shown on any of the output anchors.

Could you please tell me how can I solve this problem?

Thanks,

Boris. 

[Biswarun]

Please be more clear and provide a minimum reproducible example.

[Emmanuel_G]

Hi @BK_OPTUS ,

This is really very strange considering that in the input anchor of the block until done tool there is data present.

Do you have an error in one of the tools downstream of tool anchor 1 block until end?

If so, you should know that if there is an error at this level, there will be no output data from the tool that is connected to anchor 2 or 3 of the block tool until done.

Tell me if in your case you have no errors, I will do other tests.

[BK_OPTUS]

Hi @Emmanuel_G , 

I found no errors after the block until done tool. 

Attached you can find two files with the input anchor output and output anchor results (empty). You can see that no errors are shown after anchors 1 or 2 after the script was run. 

Thanks,

Boris

[hberg]

I have also encountered occasional unexplained problems with the Block Until Done Tool (BUD) when it refuses to supply any data out of any connector.  l believe that there is a bug that persists until at least v2022.3.1.420. The bug is triggered by some operation that is normally allowable, but somehow interferes with the BUD code.

I have attempted to create a minimum reproducible example. However, the problem inevitably goes away after other objects are removed to simplify the workflow.

So until I can generate a test case to illustrate a bug report, here is how I approach resolution..

Try removing the BUD altogether and temporarily bypass the race condition (e.g. send results to separate files instead of two worksheets in one file). Once this works, try adding the BUD again. If the problem stays, then look for some other issue somewhere else on the workflow. The issue is likely UPSTREAM because downstream has already proven to work OK.

Here are some situations that normally work fine for any workflow without a BUD, but seem to trigger the problem. I have no proof, but removing these from a problematic workflow will often resolve the problem. Consider that these might be anywhere in the workflow, and look for:

- a Union Tool or Join (or perhaps any tool) that has an input that could be an empty data set. If one is found, either remove the logic for a test or artificially ensure the data set is *never* empty to see if this resolves the problem.

- a Container (anywhere on the workflow) that has been disabled. Try enabling any such container(s) to see if this resolves the problem. (This may be similar to the empty data set situation mentioned above)

- any Tool that is missing an input. Try removing this Tool altogether to see if this resolves the problem. (logically, this no direct influence on the data flow, but perhaps this condition interferes with the BUD code).