Alteryx Union With Dynamically Switchable Control Containers

[bmillar777]

Hi everybody, 

I've got a question that's been bothering me for a while and I haven't been able to find a solution to. I've included a screenshot with a simplified example of the issue. 

It relates to a scenario where I have a set of PDF reads to do and have to dynamically come up with a solution to determine which ones. This works well using the Filter tool to turn containers on and off and if all processing is done inside each control container, all is fine. 

However, if I need to combine the results outside the control containers, the Union tool fails with the "No incoming metadata from one or more upstream tools". I've tried various solutions to resolve this issue with no luck. Limiting the number of PDF reads is critical for my use case as one of my routines is already taking over 2 minutes to complete, unacceptably long. 

Does anybody have any ideas on how I can resolve this? 

Thanks :)

[Warcry]

Change the configuration to Ignore - Continue Processing Records

 

[bmillar777]

Unfortunately, that didn't resolve the problem.

I've also tried to set "Auto Config by Position" and even to "Manually Configure Fields" and enabled the non-blocking option, but nothing from this angle seems to resolve it.

[adighe]

I have the exact same issue. Have tried all the options for the union tool. Amp on and off did not make a difference. Any clue as to what different approach to take in such situations?

Not all streams will have data. There are only two fields coming into the union tool with same names and datatype and size. I have set it to "Auto Config by name"

Error: Union (458): No incoming metadata from one or more upstream tools. Check the input data and run the workflow again

[bmillar777]

I never found a solution in the end and maybe there isn't one. The closest I got was adding the Record ID tool to the Union inputs which removed the errors but didn't output any data :) It might be possible to use the Python tool to make it work, although I haven't had a proper go at that to see.

[GMG0241]

Hi, I think the issue COULD be that it's due to having a split stream. Please see the attached screenshot/example which I believe should solve your problem by creating a single stream, although I'm not 100% sure as I don't have access to the Computer Vision tool set 

[flying008]

Hi, @bmillar777  @adighe 

There are some issues that need to be confirmed first:
1- Do all your test*.pdf files exist?
2- Do all your PDF file paths have access permissions and are they set correctly?
3- Do all your PDF to Text tools have normal output? (The output here means at least an output header, or a standard header and data record, not nothing.)

If the answers to the above three questions are all yes, then under normal circumstances, the error in your screenshot will not appear. At the same time, the most likely problem is problem 3. For some reason, the PDF to Text tool will not output anything, so the Union tool will report an error due to the lack of metadata for one or more incoming connections.

**************
Solution:
1- You need to modify the existing workflow, add an Output tool after each of the three PDF to Text tools, and output each data to the file format you specify. Remember that the three output files should be placed in the same folder.
2- If the data structure of the three files is exactly the same, you can use the wildcard option of the Input tool or the Dynamic Input tool to Union all the data, so that the above error will not appear and affect your work.
3- If the data structures of the three files are not exactly the same, you may need to use a batch macro to complete the above Union operation. There are too many such macros in the Gallery, you can download them directly and use them.
4- You can also use 1 Control Contain to control the order of the above two steps relative to the three PDF to Text tools, which should be a very easy thing for you.

That's all, I wish you good luck!

[adighe]

@flying008,

In my case it's not files but the download tool with various DB or API calls that might not be executed. That causes errors before the flow reaches the join. The errors were hidden in control containers that collapse. But this causes the metadata to not reach the union.  I have to figure out how to pass metadata or dummy data through every path that reaches the join and then remove it.

 

[apathetichell]

can you share a screen shot of the config of your union tool? union should not require a connection is initialized - but I've seen this be sticky. I think some things to try are:

1) delete the union - re add.

2) in the containers create a text input tool with a dummy column name and no data. union this in your container. run.

the above is in standard Alteryx pre-control containers. It's possible that the control containers deploy is a bit 'special' -> if that's the case maybe throw things in a macros instead of control containers?

basically - what you are trying to do is resync the workflow cache.

[adighe]

I have used all configs for the union tool with no luck, and current config is auto config by name. Adding the dummy data is what will work. The downloads in red may or may not execute and that results in the formula/filter downstream to error due to missing variables. I added the missing dummy variables with a formula marked in green. That took care of error in that stream. Any errors upstream with or without containers will prevent metadata to flow downstream and union does not like that. 

@apathetichell  adding text input is a better idea as its very obvious what the purpose is.