Maximum Number of Categories in Category Combination?

Hello All,
We are currently running version 2.33.1, Build revision: 7ab6211, Build date: 2019-11-27 12:55

Please is there a maximum number of categories that can be combined in a category combination?

I have a complex dataset that has up to six different categories and I am trying to combine them in a category combination and it keeps giving me an error (which for some reason does not really display but shows an orange ‘ok’) but in the console, I get a 504 Gateway Timeout.

I also noticed that it still goes ahead to save but when used with a data element and added to a dataset, the form does not load (section form), the custom form designer does not load, and when I try to delete the combination, I get a 504 as well and it does not delete.


Updating category option combinations in the maintenance app under data administration gives a 504 as well:

Could someone please help us take a look at this issue?

Thank you so much

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I’m not able to - if there’s some hidden limit in the system, it’s not documented as far as I know.

But then I reported another bug during the weekend related to a feature (data element “Field Mask”) that according the manual is supported by Tracker and Capture, but which turned out to NOT be supported.

so somebody from the core dev team with a good understanding of the code need to clarify if there is some unknown “hard” limit here.



Thanks @Calle_Hedberg

Let’s hope for someone who can throw more light


Hi there @ifeanyiokoye,
Each category that is added is multiplying the amount of category combination options. Therefore, there is a soft limit to how many categories the system can handle. This soft limit depends on the number of options in your categories, and is therefore not absolute. It seems that you are now reaching this limit in your system, and adding one more category would not be possible.

Best regards,

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Dear @Markus, thank you for this insight and this makes sense. I initially thought that this was an issue with our database but I recreated all the category options and categories on the 2.33.1 demo server and when I tried to create the category combination, it failed too and gave the same errors. It however still saves the category combination (see KP Testing on demo server).
However, this seems to create some sequelae:

  1. You cannot delete the category combination - times out in the process
  2. Trying to delete the category combination also fails. Even when all the components are removed, it still fails to delete
  3. Update category option combinations under maintenance–data administration also gives an error
  4. We noticed that saving favorites also times out and we do not know if this is related to the ongoing problems or something completely different.

So it appears that after removing all the categories and saving the category combination, it does not change anything in the system. We noticed from tailing the logs that trying to delete any of the emptied category combinations leads to this continuous activity on the catalina logs even after it has timed out on the front end.
All these have been reproduced on the demo server.
Could someone help us look at this?
Thank you.

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@Markus, just asking if it is possible that these soft limits be increased?

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Hi @ifeanyiokoye ,
Im facing same problem here,
please did u find any solution for that ?

thank you

Hello @ssari, we had to reduce the number of options in one of the categories before we could get this to work. I am also not 100% sure about this, but I think the update to the category option combos takes time and may time out in the process and show an error but I think that keeping at it eventually resolves this… but this is an absolute postulation on my part.
If you can cut down the number of your categories, that helps.
I asked a question about possibly increasing the limits but have not gotten a response yet.
Sorry, If I could not be of any more help.


Hello @ifeanyiokoye, finally it worked
So as you said it just take time bec there is no error, so for that i increased on server timeout and that resolved my problem i was able to add 3 different categories and create combination of (31x7x70) which generate 17361 category combo option , it tooks about 15 min

Fantastic indeed. I did not have this many in our combination. Good luck with the rest of the implementation

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