Data source building taking too much time for data source of type : Form

On our local instance(http://echisethiopia.org/), I created a data source of type forms. I rebuilt the data source and building did not finish for days(more than 5 days).On the preview table, the total row count changes but it’s too slow relative to other data source of type: case.

Thinking there may be a problem on the data source query, I took the same data source into the cloud (commcarehq.com), building finished overnight confirming that the data source works.

On our local instance, data sources of type case, builds and finishes properly.

It sounds like maybe the rebuild failed and the slow growth could be attributed to new data coming in. Are you able to access the celery logs for the rebuild task and see if there are any errors?

yes, I do have the celery log. Its huge(45 MB) .searched for "error" and 35545 results are found.What should I look for?

You should look for anything that looks like an error in the rebuild data source task. Probably the easiest thing to do is tail the log file while you click "rebuild" and then see if there are any errors.