
The actual failed one is db.2 with Unit mongodb.service not found., however web.1:abort suggests that there was an error on it: Failed installing packages on 'web.1': W: --force-yes is deprecated, use one of the options starting with --allow instead., leading to a false troubleshooting direction. But it looks like it's just the last line in the output from the installation script and it turns out to be just a warning from apt-get.