This question stems from a project I'm working on using a database. Clients pull a job from a database, run it, and commit the results back into the database. I've got a working prototype that does pretty well, except for a few issues (that may be chalked up to bad design). The first involves race conditions: when a client pulls a job from the database, it first checks the job's parameters, then updates the job status to "Running", at which point the job cannot be pulled by another client. The race condition occurs when two clients pull the same job and try to insert the same job's results into the results table (primary key error). I'm planning to add a "Pending" phase to avoid this. A second one comes when the DB goes down, for whatever reason. It's on a laptop, so downtime is expected on occasion, but these errors are harder to come up with a strategy to fix. So now that you see a little where I'm coming from, the main question. How do you guys set up error handling? I've been considering using a construct like this: The basic idea is to drop deeper and deeper into Error-No Error case structures, and handle errors by continually executing the code in a while loop until we get no errors. The issue with this approach is mostly that a lack of support for recursion makes this code very very messy. I also am not sure how to determine what error codes a set of VIs uses, in order to make proper handling cases for all of them. I understand the importance of error handling, and get the basic implementation of it, so the NI docs and Sixclear videos are mostly oversimplified. What I would like to find is an in depth resource for error handling constructs. Is there such a thing?

Have a look at the attached PDF - it shows a pretty comprehensive list of how to handle errors within a loop/application. It doesn't cover things you might want to do with the error such as notify the user, log the error etc. What you actually do will depend heavily on your application!

LabVIEW

In practice, how do you handle errors?

Solved!

Hi ijustlovemath,

"Do you have any suggestions for looking up error codes for a given VI? Sometimes I just dive into the block diagram, but it's often the case that the low low level subVIs are locked." - Sam was correct when he mentioned "No, there isn't any documentation that I know of that tells you what errors could be returned by a VI.".

I have just posted a LabVIEW Idea that asks for the detailed help of each node or native VI to list the error codes that could be generated by that node or VI: The detailed help of each node and each native VI should list all error codes that can be produced b... . I added a comment to that idea in which I used your question above as a data point that supports the idea.

Kind regards,
Petru