just to add my bit of history...
  XrdClient had always sent the endsess message, not only since the last summer. It was since at least
3-4 years, if not more.

  I remember that the rationale behind this was informally discussed several times. To keep it short,
in the client it's very difficult, if not impossible, to determine what the server knows about the previous sessions,
if any, since it is mainly stateless. To add the reference that I remember, it was a simple solution to the
"file already open" problem, that may arise when recovering troubled write requests in a glitchy environment,
or when the load is high and the connections may drop without good reasons.
  The first times the need for such a thing was seen was during the BaBar reprocessings in Padova, where
the servers were constantly at full load, and the writes were sometimes failing inexplicably.
  The same issue was also seen many times in the ALICE infrastructure as well.
  I don't say that it can not be done better, just that it's a very tricky detail that can increase the number of failures
if not treated correctly.


On 05/18/2011 06:54 AM, Andrew Hanushevsky wrote:
>> Since last summer it appears that the client always sends an end
>> session request whether or not there actually was a previous session.
>> Annoying but not fatal.
> OK. I was not aware of this.
> It was a low level annoyance and it just slipped my mind. Sorry about that.
> Andy