[LON-CAPA-admin] repcopy failed and con_lost

[Mike Budzik]

Can you help us understand these kinds of errors and what can be done to
improve the user experience?

User reports:
   My LON-CAPA account showing this status "Having technical difficulties;
please check status later" on every questions.
10 minutes later:
   I log in again after 10 minutes and its okay now.

Here is what I found that seems to correspond to the user's experience
based on the times:
from error_log:
[Wed Oct 21 13:28:00 2015] [error] access to
/res/purdue/purdue_math/math16020/Functions of Several
Variables/Differentials of Multivariable Functions/Problems/con_lost failed
for []IP-ADDRESS], reason: Replication failed for
[username]_1445446334193674160_purdue_purduel1

from lonnet.log
This message is repeated 4135 times in under 5 minutes:
Wed Oct 21 13:28:00 2015 (3829): <font color="blue">WARNING: Trying to get
resource data for [username] at purdue: con_lost</font>

There are also some like this:
Wed Oct 21 13:28:08 2015 (4932): Userfile repcopy failed for
uploaded/purdue/4o12229eff3c955c9purduel1/supplemental.sequence
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.lon-capa.org/pipermail/lon-capa-admin/attachments/20151022/78867289/attachment.html>