By Google's update at January 19, 2018, fetchAll method was added to the UrlFetch service. When I saw the usage, I couldn't find the detail information about the actual running state. So I investigated about it.
As the result, it was found that the fetchAll method is worked by the asynchronous processing. The returned data is reordered by the order of requests. By this, it was also found that if you want to retrieve the data from the several URL, the process cost of UrlFetchApp.fetchAll() is much lower than that of UrlFetchApp.fetch() using for loop.
The sample scripts for server side and client side are as follows.
In this report, 5 Web Apps were used as the servers. At first, 5 standalone projects were created and the following server script was put to each project. Then, Web Apps was deployed for ea
