On 19/10/16 16:15, Marco Ceppi wrote: >> 2. Don't colocate units if at all possible. In separate containers on the >> same machine, sure. But there's absolutely no guarantee that colocated >> units won't conflict with each other. What you're asking about is the very >> problem colocation causes. If both units try to take over the same port, or >> a common service, or write to the same file on disk, etc... the results >> will very likely be bad. Stop hooks should clean up everything they >> started. Yes, this may break other units that are colocated, but the >> alternative is leaving machines in a bad state when they're not colocated. >> > > Colocation is a rare scenario, a more common one is manual provider.
Subordinate charms only make sense when collocated. And I would argue that subordinates are extremely common, at least in production environments. In any production deployment I expect some form of monitoring (nrpe, telegraf). Many deployments will also use logstash-forwarder, landscape-client, ntp, container-log-archive and other subordinate charms. So you are looking at 3-4 or more services on each juju machine, including LXC/LXD guests and manually provisioned systems. In this context clean up is very important because it's not unusual for operators to switch technologies. For example replace telegraf with node-exporter or collectd. Regards, Jacek
signature.asc
Description: OpenPGP digital signature
-- Juju mailing list Juju@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/juju
