I have a problem with a SharePoint 2013 Server where it most of the times takes 40-60 seconds to open a Word file from there.
The size of the file does not matter and also not if I do it in a big library or in a small one.
When I turn on the tracing I see a lot of requests which need exactly 21 seconds. This leads me to the point that for some reasons internally the SharePoint gets a timeout.
Here are some of the request in the traces which takes exactly 21 seconds
http://sharepoint/sites/CRMDocuments/_layouts/15/WopiFrame.aspx?sourcedoc=%2Fsites%2FCRMDocuments%2Fincident%2FDCP%20Customization%5F57037689EBC7E41180CB00155DC8D406%2FAR%2D07688A%20Bilbrough%20Co%20Ltd%2D2%2Edoc&action=interactivepreview&wdSmallView=1
http://sharepoint/sites/CRMDocuments/incident/DCP%20Customization_57037689EBC7E41180CB00155DC8D406/
http://sharepoint/sites/CRMDocuments/_vti_bin/cellstorage.svc/CellStorageService
The same url requests are sometimes quick.
I have really no idea where I should start searching for the problem. Would be great if someone has a hint .