So we're migrating from On-Prem 2010 to Office 365 and I need to convert some of our simple calendar webparts to online solutions.
I've setup an External Content Type in 365 using SharePoint Designer. It maps to an internal WCF service and authenticates using domain credentials from the Secure Store. The "GetAll" method returns around 300 items total, it's a small dataset.
I also setup an External List for this content type so I can use the REST api to pull data into a kendo ui scheduler via jquery ajax.
Now, this all works, but the REST api ajax request to the external content type is painfully slow. I've seen it take upwards of 1m30s. It's intermittent. 5s, 10s, 30s, etc. Sometimes it returns immediately.
A couple things to note:
- I traced the request coming into our internal WCF service and the request doesn't actually hit the service until the end, meaning Office 365 or "the network" is holding the request for the duration; it's not the internal service causing this delay.
- REST api calls to native sharepoint lists work fine, it seems to only affect the BCS-related calls
- I've tested this with multiple users and devices and they all experience the same issue
Does anyone have insight into what might be happening here?