I'm offering large downloads from my server of around 6.5gb and doing so using PHP and x-sendfile.
This has been working fine for months however recently the downloads have been ending prematurely for users at anywhere from 3gb-5.5gb.
No errors are given in the browsers (tried Chrome, Firefox and IE) they behave as if the downloads have completed but the filesize is smaller than it should be.
From my limited understanding this usually happens because no data is sent for a certain period of time and the browser mistakes this for the download having completed.
However I am struggling to find any specific information about how browsers behave in this regard.
I have contacted my host to see if they can help identify the problem at their end, perhaps the connection is being interrupted or something, however they insist it must be an issue with my servers configuration, even though nothing changed in the setup of the server around the time this began.
Now I am at a complete loss of how to investigate this. The time the download stops is completely random. Different file sizes, different amount of time taken and no errors in the server logs or in the browser.
Can anyone offer any suggestions on how to investigate this or has anyone had any similar problems before and found a fix?