Is there a character limit to the event data in a Tempo post? We have a process

Question

Is there a character limit to the event data in a Tempo post? We have a process that failed with the error message: There is a problem with task “Post System Event to Feed” in the process “Submit a Request”. An error occurred while trying to post to the feed. Details: An unexpected error prevented adding a feed entry (error: [could not insert: [com.appiancorp.tempo.rdbms.EventFeedEntry]]) (APNX-1-4181-000).
The only anomaly that I can see is that the user entered 3599 characters of test that we are trying to post in event data in a feed. ...

Eduardo Fuentes · Answer

The non-configurable limit (which is set during the first application-server start-up) is 4,000 characters. However, you need to keep in mind that for the data of a feed entry part of those 4,000 characters is used by Appian to build the corresponding XML that describes the data. For a simple Label-Value structure with two rows of data the metadata will be ~ 310 characters. If you are expecting a large number of characters you may want to add logic to your model to inspect the size after submission and if it exceeds 3,700 characters take the flow back to the same form and ask the user to reduce the number of characters (this approach should be based on activity chaining rather than on JS to keep it Tempo compliant)