On premises gateway: Timout saving large pictures to SQL DB

[PowerFabi]

Hi community,
I am irregulary getting an error when I try to submit pictures to my SQL database. The Flow is started by a PowerApp and does several steps including writing in connected tables in the same database.
The error message is as following (I cutted out some IDs and urls):

{ "status": 404, "message": "The gateway is either offline or could not be reached.\r\n inner exception: Gateway on endpoint 'sb://asdf.servicebus.windows.net/bbbe/' is unreachable.\r\n inner exception: The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '00:01:00'.\r\n inner exception: The write operation failed, see inner exception.\r\n inner exception: The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '00:01:00'.\r\n inner exception: An established connection was aborted by the software in your host machine\r\nclientRequestId: 472d", "source": "sqlconnectionprovider-asdf.azurewebsites.net" }

I could still find out that it only happens with pictures that are larger than around 3MB. Therefore I am very convinced that the error message is either related to the size of the Base64 sting in which the picture is naturally converted throughout flow or to a timeout in the on premises data gateway (as said in the error message).
Can anybody help me with this issue? If you need more information don't hesitate to ask.

[v-bacao-msft]

Hi @PowerFabi,

Could you please share a full screenshot of the configuration of your flow?

In addition, I noticed that the error message indicates that Gateway is offline. Please ensure that there is a good network environment during the transmission and that the gateway is connected. You could try to update the gateway to the latest version.

Please provide more details and which should be helpful for us to share a further suggestion.

Best Regards,

Barry

[PowerFabi]

Hi @v-bacao-msft,

as the flow is pretty large, I had some problems getting if fully on my screen. At the start i am initializing some variables. The trigger is PowerApps. 
As you can see I am using the SQL connection in some previous steps. The flow has never faild on theses steps. That's why I was currious that the outer exeption of the error message is saying that the gateway is offline.

Here is a more detailed screenshot of the "Add Pictures part":

I put it at the end of the flow so I only have to add these steps manually if it fails. 
The "PA_Photo2" parameter is a base64 encoded sting with a length between 3 milion and 4,5 milion figures.

I asume that this is simply to large for the on-premises data gateway and some kind of timeout or limit is hit. But I couldn't find out where I can change this timeout.

The gateway has the version number 3000.0.144.3 (October 2018). I guess it is the newest.

[rajgilbert]

PowerFabi - Did you ever figure out the solution to this issue?

[PowerFabi]

@rajgilbert  - Unfortunately not. Some days ago I dicovered by chance that one of the known limitation is a limit of 8MB/ 2MB for reponse/request size with the sql server connector through on-premises gateways (https://docs.microsoft.com/en-us/connectors/sql/#known-issues-and-limitations). But that only confuses me more because the limit I experienced is between 3MB and 3.5MB so this doesn't make so much sense, neither.