Re: [Libguestfs] [PATCH nbdkit 0/2] Add new retry filter.

This is a retry filter implementation as outlined here: https://www.redhat.com/archives/libguestfs/2019-September/msg00167.html It is only lightly tested. One way to test it is to try an SSH copy (see the commit message for patch 2/2), and in the middle of the copy kill the per-connection sshd on the remote machine. You will see that the copy recovers after a few seconds. Add the nbdkit -v option to see some useful messages from the filter: ... nbdkit: ssh[1]: debug: ssh: pread count=2097152 offset=216006656 nbdkit: ssh[1]: error: read failed: Socket error: Connection reset by peer (-1) nbdkit: ssh[1]: debug: retry 1: original errno = 5 nbdkit: ssh[1]: debug: waiting 2 seconds before retrying nbdkit: ssh[1]: debug: ssh: reopen nbdkit: ssh[1]: debug: close nbdkit: ssh[1]: error: cannot close file: Socket error: Connection reset by peer nbdkit: ssh[1]: debug: ssh: open readonly=0 nbdkit: ssh[1]: debug: opened libssh handle nbdkit: ssh[1]: debug: ssh: pread count=2097152 offset=216006656 ... It really needs an actual test, which is tricky to implement. My thinking currently is that a custom (sh) plugin is the way to go, but it would also be nice to test curl/ssh/vddk with this filter -- if anyone has any suggestions on how to do that ... This patch will probably conflict with Eric's series here: https://www.redhat.com/archives/libguestfs/2019-September/msg00180.html but that shouldn't be too hard to fix up. Rich.