Hampton@DOCKMASTER.arpa (David R. Hampton) (05/14/87)
The machine:
A VAX 11/785 (or VAX 11/750) running Berkeley 4.2
X.25 board in external loop mode (ACC-5250 board)
The problem:
We can run a large batch of file transfers through the loopback
connector without any problem. However, if we try to do batch ftps
simultaneously from two different terminals, one of the sets of
transfers will hang in the middle. This hanging seems to be sporadic.
It isn't always the same terminal, nor does it always happen on the
same file, or after n transfers. Ocassionally, we can even push
through the two batches without it hanging at all. (This is rare
though.) The only constant in all of this, though, is the hung
process is stuck waiting for an accept call to finish. (core dump +
dbx == accept)
The solution:
(Help?)
+---------------------------------------------------------------+
| David R. Hampton Ma Bell:(301) 859-4537 |
| Hampton @ Dockmaster.ARPA |
+---------------------------------------------------------------+rgoguen@MIKEY.BBN.COM (05/15/87)
David I had the same problem. I would sometimes have upto 50 hosts ftp'ing to a vax 11/785 running 4.2bsd. We had used the ftp librarys and created our own ftp batch program. What I did to stop the hanging was to add timeout in the MakeDataConnection() before trying to connect(2) to the host. I could easly get 8-9 hosts hung unless I added this time-out. In order to do this you have to have the ftp library source code. Bob Goguen