Test suite: remote shell instability
Although very rare, the remote shell can get into a state where it stops
responding, resulting in the test suite waiting for a response forever.
The reason for this has proved hard to determine, but it seems to
basically only happen for the very first interaction with it, i.e. when
running VM.wait_until_remote_shell_is_up().
I think it has to do with the fact that its transport is TCP on the host
bridged to a serial device on the guest (see <serial type='tcp'> in
Libvirt domain XML format). Perhaps the TCP state vs the guest’s serial
port’s state gets out-of-sync if the TCP packet times out before the
serial port is up and running?
Related issues
- Related to #8941 (closed)
Original created by @tails on 5491 (Redmine)