On 2021-05-01 23:54, Brett Lymn wrote:
On Sat, May 01, 2021 at 12:58:50PM +1200, Lloyd Parkes wrote:
Germany is pretty much the opposite of New Zealand. It's close to
everywhere, but its last mile access speeds are a bit infamous.
Just for you info... there are a few NetBSD developers in .au, my self
included. I haven't
had any issues with cvs disconnects. Not to deny you have an issue, just
letting you know
it works ok for people near you.
Not anywhere near such a location, but just adding that cvs works fine
for me too, but yes, there is a lot of disk activity on the local
machine before anything even starts downloading, and a lot of activity
at the end where it updates file metadata as well as clean out empty
directories (if you added pruning).
I'm running some tests on other local clients and against other CVS mirrors
in the hope that come up with a better characterisation of the problem than
"it doesn't work".
If you have the space, a tcpdump from both sides of your firewall may provide a
clue.
I suspect what is commonly the problem here is related to the fact that
cvs has such a phase at the beginning where it is scanning through the
file system, which can take quite a while. Some NAT devices along the
path sometimes have timeouts on existing connections that if no traffic
is happening for a while, they are dropped, even though there hasn't
been any FINs on the connection.
So a connection that just don't have any traffic for a while are hit by
this, which is exactly the pattern you have with cvs.
I've seen the same effect on a simple telnet session, where ssh survives
fine. And there it's just that when the connection is idle, telnet is
not creating any traffic at all, while ssh do generate a bit of traffic
even if there is no activity.
So one obvious solution is to use something like ssh as a carries for
the cvs traffic, if possible, or else see if some kind of keepalives can
be enabled on a connection, to defeat NAT and similar devices which
aggressively drop connections on which there is no traffic for a while.
(Or, of course, if there is a NAT you have control over, you might be
able to change how it behaves...)
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: [email protected] || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
