Update Item in parallel flow causes error

[Charles-v-D]

Hi all,

I'm running a flow where there is a parallel flow. In both branches of the flow there is an "update item". when the flow runs the two Update actions trigger at the same time. This causes an update error as the first Update is still working while the other is starting... 

error message:

{

"status": 400,

"message": "Save Conflict.\n\nYour changes conflict with those made concurrently by another user. If you want your changes to be applied, click Back in your Web browser, refresh the page, and resubmit your changes.\r\nclientRequestId: f477eca1-ee41-415c-a218-35c8448dca02\r\nserviceRequestId: 01e1d99e-90c7-8000-7aeb-1d8907ded7cb"

}

I have added a Delay function but this is not secure & guarnteed solution. Is there a way to check if my Item is "ready" for updating... something like  with a "wait while"....

Please help?

regards

Charles

[ScottShearer]

@Charles-v-D :

One solution to your issue is as follows:

1. Declare a variable before the parallel actions - my preference would be for a boolean variable initialized to false
2. After the update item action in one of the branches, set the variable to true
3. In the other parallel branch,  use a do until and loop until the variable is true.  Immediately after the loop (but not in the loop), insert the second update item statement.

If you use the do uuntil loop, you should probably click on "change limits" and consider changing the default settings of 60 and 1 hour.

This obviously makes diminishes the value of the parallel action.  However, unless you take this or a similar action, you are likely o run into contention issues because both action are attempting to update the same record at about the same time.

[Charles-v-D]

@ScottShearer 

Thank for the quick answer. Based on my limited knowledge on this; I would interpret your solution to "cause"  that if branch 1 has not reched the update (a approval is pending and has not been answered yet).. the second branch (where the parallel approval might already has received answer) would never be updated.. until answer from branch 1 is completed.....

I'm in need to have item updated immediatly after receiving approval request response in each of my branches... 

Any ideas on how I should approach this?

Thanks

Charles

[ScottShearer]

@Charles-v-D 

I believe that your description of my suggestion is accurate.

However, after seeing your Flow, I am having trouble understanding why there is an issue.  It is unlikely that both approvers would approve at exactly the same time.

That said, here are two additional options:

Click on the elipses for the update item action and click on settings.  Then you can experiemnt with the retry policy.  In my example below, I selected Fixed interval.  I haven't tested this as a solution, but it is worth a try.

As another alternative, you can configure a second update item action and configure the "run after" setting as follows:

If you go with this approach, there may be other changes required in your Flow as well.

[KA]

@Charles-v-D @ScottShearer I found this conversation to be very helpful.  I have a Flow with 11 parallell paths kicking off at the same time and was encountering multiple "save conflicts".  As a starting point, I have added a unique delay to each path (5 seconds, 10 seconds, 15 seconds, etc) to space them out.  We'll see how this goes.  Good to have the other options mentioned in reserve if I need something more.