How to handle the exception of a node in process and define a different flow if exception occurs?

I don't think that's possible. There is no way to handle exceptions and capture alerts in Appian.

It depends what is the configuration on the node. Exception can be of many form, if it is coding error we cannot handle this apart form solving the issue, apart from this there can be null handle scenario, may be data issue with the service call. For this kind of issue we can handle it.

One approach is to wrap the node inside a subprocess and have an exception timer on the subprocess inside parent process. When the node fails inside the sub process it will wait till the timer event then can route to error flow as you call it.

Hi ravir93,
Thanks for your response, as you told coding error and data exception we are already handling but I need to know if there is a way to handle the service errors in the process and proceed further and take the exception path in the process flow.

Hi Harsha,
Thanks for your response, I think this will work but I have a question here as the process flow breaks whenever there is a exception in the node, will the subprocess returns the result after the timer event?

No, as the process breaks, there will not be any output for the variable configured to that node. In case if you want to know that this sub process execute successfully or not, you can make use of flag variable.

Hi ravir93,

I have wrapped the exception case node in a subprocess and called it in the parent process as a synchronous process and using a flag variable to update if the node is success, as the node breaks due to exception the parent process also is not moving further after the subprocess execution.

First of all set the flag at the End of the sub process, so in case your flow breaks in between your flag will be blank otherwise it will have true. You need to set the timer on the sub process setup as per your requirement (for eg., say 1 minute). Please see the attachments.

Let me know if this helps..

Hi ravir93,

Thanks for your response, ill try the same as you suggested.

Hi @rpbalaji2006 as per my understanding, if you are more. Concern about performance, then do not use timer because it runs in background which degrades the application and server performance.

Now coming to your query, first of all, end-user should never be informed about errors, because it's the responsibility of administrators to deal with these errors and because they are configured under alerts tab hence they will be reported by Appian and also they will have e access to designer to check the respective alerts.

You should never complete the process in case if node breaks, because this will cause you unexpected response / behaviour.

For example, you next task is completely depending on previous process response, and now because you have timer configured so it will trigger the next process, now to handle that, you need to define a gateway which checks for a variable if it's null then terminate the process, but process should not be configured in that way, because let's say, your task got broken, and if process didn't terminate then admin team can inspect and fix the issue by adding the patch and will restart from that node.

Timers are best for the use case when you want to configure some schedulers in your application.

Hope it will be helpful to you.