Allow only 1 instance of a flow to run at the same time

[DanielAmico]

Hello all, I would like to know if there is a way to avoid the same flow to run while there is another instance of this same flow already running.

This is because I've noticed that when 2 or more instances of the same flow are running at the same time, the data manipulation that it's performing turns into a "complete mess". This does not happen if I wait for the running flow to complete before starting a new one. 

However, this limitation is very bad because I want to be able to share the flow w/ other people and they will eventually start it at the same time and the final result would be incorrect.

Basically, my flow (manually triggered) extracts some data from SQL DB (Azure), then I use an Excel template file (stored in my OneDrive for Business) w/ a table in order to be populated w/ the data from SQL. For this step, I have to first list all the rows in the table and then I loop through it and delete them all before I add the new rows that are coming from SQL.

After that, I inserted a 1-minute delay before getting the file contents /metadata and then send the excel file by email.

See the setup of my flow attached. 

I appreciate some help - as I said, what I want is to avoid this flow to be initiated at the same time because if it happens, my excel template file turns into a mess (conflicting/incorrect information is sent by email probably because one instance of the flow is inserting rows at the same time or removing rows at the same time of the other and vice versa)Setup of my flow

Thanks, Daniel

[DanielAmico]

Is anyone able to help? No replies until now.... 

[v-xida-msft]

Hi @DanielAmico,

Microsoft Flow is multi-threaded, there is no way to detect if some other instances are running at the same time in Microsoft Flow currently.

I afraid that there is no way to achieve your needs in Microsoft Flow currently, if you would like this feature to be added in Microsoft Flow, please submit an idea to Flow Ideas Forum:

https://powerusers.microsoft.com/t5/Flow-Ideas/idb-p/FlowIdeas

Best regards,

Kris

[Germinal]

Has this been solved?

I've got the exact same issue.

[Mike2500]

The main situation is unchanged, the same flow can be running at the same time if triggered. Two basic workarounds: 

1. Modify the trigger so that it won't be triggered multiple times in the same timeframe. For example. if the flow is on a schedule to run once every 15 minutes, then it won't run twice at the same time. 

2. Have something like a sharepoint list that tracks if the workflow is running. The first step of the workflow would be to retrieve a given list item and check the status field, for example. If the status empty, then set it to "running", and then proceed. If another flow instance runs at this point, it will see a status of "running" and will then simply exit. Of course, this isn't foolproof, as if the flows run at exactly the same time, they could wind up both reading the status of empty and proceed, though since this update process would happen quickly, the chances of a collision would be greatly reduced. 

[gulima]

Same problem here... is there a idea link to vote?

[Jcook · Accepted solution]

Hello @DanielAmico

On your trigger,
Click the 3 dots,
Now click settings.
Enable concurrency, and set it’s value to 1.

** Update - I have written a Blog on this concept **

Power Automate – Limit Runs to Trigger One at a Time – Flow Alt Delete – Josh Cook [Microsoft MVP]

—Josh
If you like my post please hit the "Thumbs Up" -- If my post solved your issue please "Mark as a Solution" to help others

[Anonymous]

@Jcook  thanks for this tip as it resolved an issue we were having.

[Jcook]

Awesome @Anonymous glad it had helped you!

@DanielAmico Could you please let us know if this has solved your issue. This would be even more helpful in letting others find this answer. Thanks

@v-xida-msft

[Nithin_Vanam]

I almost went ahead to implement some sort of locking mechanism to control the flow runs but your suggestion saved me a lot of time and effort. Thank you @Jcook .

[mboonie]

Hi. Can you help clarify something?

Does Concurrency=1 mean one instance at a time per item, or 1 instance at a time over the whole tenant?

My flow is triggered when a file is added or modified (including properties) in a SharePoint library. I can't figure out (for libraries, anyway) how to leverage Trigger Conditions that rely on a particular value (the column "RunWorkflow"=True is what I usually use) because someone inevitably has the file open and I'm unable to turn that condition OFF, so any subsequent changes to the file re-trigger it.

I just want to prevent the workflow from running AGAIN (in parallel) on the SAME ITEM.

[Jcook]

Hi @mboonie 

Setting the Concurrency to 1 will only affect that particular Flow. This will not affect Tenant / other Flows in any way.

Setting to 1 will only allow the Flow to run 1 at a time. So there is 0 parallel runs. A second run will not be triggered until the previous run has finished. 

[mboonie]

Actually, it still doesn't quite answer my particular question. I'll try to explain using a very stripped down version of my flow.

I have a flow called myFlow; it is triggered by adding or editing a document in the Documents library for my Team site. It takes three days to run because it allows 1 day for each of three edits that need to be made. Also, because additional edits are expected to be made to that same document as the flow is running, I need to have a way to stop the flow from being re-triggered for that item; it needs to run its course.

So, now I set the concurrency of the workflow itself to 1 and add a document to the library. The workflow myFlow is kicked off and the three-day clock starts ticking. And, since this is a busy library, someone creates and edits a second document in the same library on the same day, an hour later. 

The question I have is this: Will I have to wait three days for the workflow to finish with Document 1 before it will start on Document 2?

[Jcook]

@mboonie 

---

@mboonie wrote:

The question I have is this: Will I have to wait three days for the workflow to finish with Document 1 before it will start on Document 2?

---

Yes the Flow would wait until the first Run has finished. So for your use case/solution I would say Concurrency set to 1 would not be beneficial.

I suggest that you create a new post detailing what you have mentioned above. This will help others find your issue and try to help solve. 🙂 

[Germinal]

@Jcook, thanks a lot, I think that should work but can we clarify something; as 1 occurrence of the flow is running at a time, do the new trigger actions queue up to start a new occurrence of the flow (when occurrence is set to 1)? I mean if several actions triggering the flow are filled in more or less at the same time, does the flow run them one after one in a chronological queue? Or are the next actions ignored/forgotten?

BW

[Nithin_Vanam]

@Germinal,

I have tried concurrency set to 1 with a CDS trigger and the flow runs are queued and in waiting status from what i have observed.

@Jcook, correct me if i am wrong.

[Anonymous]

@Jcook 

Hi,

Will this "hold" the flow to run after first has finished or does it just not allow flow to start?

IE I have a flow triggered by emails, these come in from all over, I would like them to queue up.

Ta

Mark

[RameshMukka]

I have a State Machine Flow on a SharePoint list which goes with 4 different approvers. Any time an approver rejects it, the flow goes back to requestor with custom approval actions "Submit for Approval" and "Withdraw". Here the requestor can make changes to the list item and "Submit for Approval" again. I dont want any flow to be triggered again here. I am already using a flag (StartWF text column) to decide whether to run the flow or not during the flow run. During this entire process, if my List item which is under approval process is modified, my flow is triggered again causing parallel runs which is a great confusion. How should I avoid this? Does Concurrency control setting help me here? I dont want flows to be queued for a given item while a flow is already running on that item.

[Anonymous]

Hi Josh,

I tried to implement your solution but I get an error in my flow. The first instance works fine, but the subsequent flows fail. I get the below error when I am trying to create a file in SharePoint: 

{"statusCode":400,"headers":{"Vary":"Origin","X-SharePointHealthScore":"3","X-MS-SPConnector":"1","X-SP-SERVERSTATE":"ReadOnly=0","DATASERVICEVERSION":"3.0","SPClientServiceRequestDuration":"64","SPRequestGuid":"5b5735a9-cf16-4f77-8359-f2a8e819caae","request-id":"5b5735a9-cf16-4f77-8359-f2a8e819caae","MS-CV":"qTVXWxbPd0+DWfKo6BnKrg.0","Strict-Transport-Security":"max-age=31536000","X-FRAME-OPTIONS":"SAMEORIGIN","Content-Security-Policy":"frame-ancestors 'self' teams.microsoft.com *.teams.microsoft.com *.skype.com *.teams.microsoft.us local.teams.office.com *.powerapps.com *.yammer.com *.officeapps.live.com *.office.com *.stream.azure-test.net *.microsoftstream.com;","MicrosoftSharePointTeamServices":"16.0.0.21402","X-Content-Type-Options":"nosniff","X-MS-InvokeApp":"1; RequireReadOnly","Timing-Allow-Origin":"*","x-ms-apihub-cached-response":"true","Cache-Control":"max-age=0, private","Date":"Thu, 17 Jun 2021 09:27:14 GMT","P3P":"CP=\"ALL IND DSP COR ADM CONo CUR CUSo IVAo IVDo PSA PSD TAI TELo OUR SAMo CNT COM INT NAV ONL PHY PRE PUR UNI\"","X-AspNet-Version":"4.0.30319","X-Powered-By":"ASP.NET","Content-Length":"376","Content-Type":"application/json","Expires":"Wed, 02 Jun 2021 09:27:14 GMT","Last-Modified":"Thu, 17 Jun 2021 09:27:14 GMT"},"body":{"status":400,"message":"A file with the name Shared Documents/Solution Testing/CreatedDocs/New file b6706584-9279-4ab6-afff-e45885d78434 already exists. It was last modified by i:0#.f|membership|XXXXXXX on 17 Jun 2021 02:27:07 -0700.\r\nclientRequestId: 5b5735a9-cf16-4f77-8359-f2a8e819caae\r\nserviceRequestId: 5b5735a9-cf16-4f77-8359-f2a8e819caae"}}

Before I tried using the concurrent suggestion the flows used to run simulaneously and I got the below error:

{"statusCode":400,"headers":{"Vary":"Origin","X-SharePointHealthScore":"2","X-MS-SPConnector":"1","X-SP-SERVERSTATE":"ReadOnly=0","DATASERVICEVERSION":"3.0","SPClientServiceRequestDuration":"58","SPRequestGuid":"413e8b7e-25f0-4f24-81ef-1fd5e886ed4d","request-id":"413e8b7e-25f0-4f24-81ef-1fd5e886ed4d","MS-CV":"fos+QfAlJE+B7x/V6IbtTQ.0","Strict-Transport-Security":"max-age=31536000","X-FRAME-OPTIONS":"SAMEORIGIN","Content-Security-Policy":"frame-ancestors 'self' teams.microsoft.com *.teams.microsoft.com *.skype.com *.teams.microsoft.us local.teams.office.com *.powerapps.com *.yammer.com *.officeapps.live.com *.office.com *.stream.azure-test.net *.microsoftstream.com;","MicrosoftSharePointTeamServices":"16.0.0.21402","X-Content-Type-Options":"nosniff","X-MS-InvokeApp":"1; RequireReadOnly","Timing-Allow-Origin":"*","x-ms-apihub-cached-response":"true","Cache-Control":"max-age=0, private","Date":"Wed, 16 Jun 2021 09:08:41 GMT","P3P":"CP=\"ALL IND DSP COR ADM CONo CUR CUSo IVAo IVDo PSA PSD TAI TELo OUR SAMo CNT COM INT NAV ONL PHY PRE PUR UNI\"","X-AspNet-Version":"4.0.30319","X-Powered-By":"ASP.NET","Content-Length":"179","Content-Type":"application/json","Expires":"Tue, 01 Jun 2021 09:08:41 GMT","Last-Modified":"Wed, 16 Jun 2021 09:08:41 GMT"},"body":{"status":400,"message":"Error in the application.\r\nclientRequestId: 413e8b7e-25f0-4f24-81ef-1fd5e886ed4d\r\nserviceRequestId: 413e8b7e-25f0-4f24-81ef-1fd5e886ed4d"}}

 This is what my flow looks like. It is failing at the create file part of the apply to each. The flow works correctly for the first run, then fails for the other consecutive flows when the trigger is initiated at the same time/a short time apart from each other. If I leave 15 seconds between triggers it always runs correctly so I am not sure what is going wrong.

This is using the concurrent technique set to 1:

If I manually leave 15 seconds between triggering the flow it works just fine:

Any suggestions? I have asked the question here: https://powerusers.microsoft.com/t5/Building-Flows/Flow-fails-when-triggered-multiple-times-in-a-sho... but no one has come back to me.

Thanks,

Freddie

[Nata123]

Hi everyone

I  set my workflow to run only one instance at a time. And it works fine, except that not all flow instances have been executed. 

I created 130 instances in dataverse table, and for each instance on creation starts a workflow. The problem is that 2 days later I am still missing about 50 workflow instances to be executed. Any clue how I can see the status of missing workflow  instances? They are nor failed or in progress, they are just not there. Last run was 19 hours ago.

Thanks in advance!