Copyright (c) 2019, Joakim Brännström. All rights reserved.
Authors
Joakim Brännström (joakim.brannstrom@gmx.com)
Updates the distssh server cache.
Design
The overall design is based around a shared, local database that is used by
both the daemon and clients to exchange statistics about the cluster. By
leveraging sqlite for the database it becomes safe for processes to read/write
to it concurrently.
The heartbeats are used by both the client and daemon:
* The client spawn a daemon if the daemon heartbeats have stopped being
updated.
* The server slow down the update of the cluster statistics if no client has
used it in a while until it finally terminates itself.