Hi Dan, This has been discussed in the past, as you found with those two Jira tickets. Personally, I'm still not sure whether a new failure relationship on UpdateAttribute in 2.0 is a good approach. I have heard from some dataflow managers that would not want to go through their entire graph when upgrading to 2.0 and update every UpdateAttribute configuration.
I have heard some alternatives to a 'failure' relationship that I would like to share as options. 1) Add a new property to UpdateAttribute that controls whether a flowfile that causes an expression language exception either yields and rolls back, or silently fails to update the attribute and sends the flowfile to success. I personally don't like this, because the use case for "silent failure" seems really like a rarely needed edge case. 2) Identify all expression language methods that can throw an exception and document that fact in the Expression Language Guide (some methods already mention they can throw an "exception bulletin"). Then implement new expression methods to check if an expression could fail, and use that in UpdateAttribute advanced rules. For example, if the format() and formatInstant() methods can fail on a negative number, we create a new method such as isValidMilliseconds(). This already exists for some cases, such as isJson() which can do a quick check of some value before calling jsonPathDelete() on it. I'm curious to hear more thoughts on this. -- Mike On Wed, Jan 31, 2024 at 11:02 AM Dan S <[email protected]> wrote: > My team is requesting a failure relationship for UpdateAttribute as seen in > NIFI-5448 <https://issues.apache.org/jira/browse/NIFI-5448> and NIFI-6344 > <https://issues.apache.org/jira/browse/NIFI-6344> as we are > experiencing the same problem where a NIFI Expression Language is throwing > an exception. In the PR for NIFI-5448 it was mentioned this feature would > have to wait until NIFI 2.0.0. I wanted to know if there is any active work > regarding this and whether eventually there will be a failure relationship > added to UpdateAttribute? >
