An important customer of ours has recently been experiencing 504 gateway timeout errors when using a secure print service that we host for them in ArcGIS Server (v11.5). We have raised a support case and have already posted in the community on this here:
https://community.esri.com/t5/arcgis-online-questions/504-gateway-timeout-when-printing-through-util...
To summarise, the solution was previously working (for approx 2 years) and involves:
- A standard print service published in ArcGIS Server (v11.5) - this is secured with standard ArcGIS authentication. This service is set as Synchronous as this is required for printing in Web App Builder.
- So that users do not have to enter credentials each time they use the service in apps, the the service has been added as an item in their ArcGIS Online organisation with the credentials stored. This item is shared with the organisation. This is a standard approach for accessing secured services.
- The URL for the above item (starting https://utility.arcgis.com/usrsvcs/servers...) is then used when configuring the Print Widget in Experience Builder and Web App Builder (the customer still has some older apps they are yet to migrate).
- When end users print from within apps in ArcGIS Online, the request goes via the utility.arcgis.com proxy, which handles the credentials and forwards the request on to the ArcGIS Server.
For the last few months users have been getting errors when printing larger/more complex prints and this is due to 504 gateway timeout errors that also state "Error from CloudFront". We have tested extensively and found that any print that takes more than 30 seconds to complete results in a gateway timeout. The prints are still successfully generated on the ArcGIS Server and there are no errors or timeouts in server.
My conclusions from investigations is that there is a timeout setting somewhere in CloudFront, which I assume is used as part of the utility.arcgis.com proxy, that is set to 30 seconds. This is incompatible with Synchronous tasks (geoprocessing / print etc) that may take longer than 30 seconds.
The timeout should be increased to something more reasonable and perhaps to match the default usage timeout (maximum time a client can use a service) in ArcGIS Server.
I strongly feel this is not an "enhancement" but a requirement and should be fixed as soon as possible.
