Take a look at the following scenario:
There are 4 apache units with the following line
Conflicts=apache@%i.service
One machine goes down.
Fleet would try to relaunch the unit on another host but there is no possible host available. What does fleet do in this situation? Are there any differents between the handeling of different options like MachineMetadata and Conflicts
I am currently thinking about migrating some of our servers and apps to a coreOS environment. One of the problems I see here is the management of persistent data as coreOS does not handle Docker volumes when moving a container to a new machine. After some research I found glusterFS which claims to be a cluster file system that could solve all my problems.
My current idea is this: I have a glusterFS container which runs as a privileged container on each of my coreOS machines and exposes a storage, /mnt/gluster, for example. In my Dockerfiles I specify that all my volumes should be mounted on this path.
The next thing I considered was which containers should obtain their own volumes and which ones should be sharing one. For example, every mysql container would get its own volume as it is able to handle replication by itself. I don't want to mess around with that. Webservers serving the same website would properly use the same volume for stuff like "user uploaded images", etc. as they are not able to replicate those data.
Has anybody tried something like this or is there anything I have missed?