I currently work in a project where the solution is hosted in SharePoint Online and Azure. All communication between the web applications in Azure and SharePoint Online is done with the client object model. Before the summer vacation everything was working just fine. When we came back a couple of weeks later nothing worked. Our applications got a lot of "Ther request uses too many resources" responses from SharePoint Online. After getting past the first line support at Microsoft we eventually got to speak to someone who actually knew what they were talking about. We found out that Microsoft lowered the limit for operations in an execute query call during the summer without notifying anyone. The limit is controlled by the property ClientCallableSettings, see http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.administration.spwebapplication.clientcallablesettings.aspx. Since that kind of properties are untouchable in SharePoint Online we had to add several execute query calls on strategic places throughout our code.
Yet another day in SharePoint paradise...
