Yes, it is server side. The server was not under high load at all (~10% CPU, memory well under heap limit) but I agree it sounds like the connections were dropped.
What I'm trying to figure out is if there is some glassfish config setting that I need to change to be able to accept concurrent file uploads. As I mentioned before, it works fine as long as there aren't many people trying to upload at the same time, and since there is no shared state between uploaders it seems that it must be some sort of server config issue.
Receive buffer size perhaps? I don't know, haven't found any good docs on *exactly* what that means.
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