Concepts
Concepts
Databases that sleep: how a database wakes, sleeps, and why each one has a single owner.
Databases that sleep#
An FENVIX database is a set of files on object storage. It is not a process that runs all day. It has two states.
| State | Meaning |
|---|---|
| Awake | Filled dot. A server holds the database open and answers requests. |
| Asleep | Outlined dot. Only its files exist, in the bucket. It makes no requests and costs storage only. |
The state is always shown as a dot and a word, never by color.
Wake#
A sleeping database wakes on its first request. The server reads the database's files from the bucket and then answers. The first request after a sleep is therefore slower than the ones after it.
If a customer needs every millisecond, keep that database awake (see Commands). A database that is kept awake never sleeps, so its first request is never slow.
Sleep#
When nobody needs a database it goes back to sleep. A closed database makes 0 requests.
Durability#
A write is acknowledged only once it is in the bucket. In our tests, 20 forced kills of the server lost no acknowledged write.
One owner per database#
A database has one owner at a time: one server holds it open and takes its writes. When the database sleeps, the owner lets go, and the next server that wakes it becomes the owner.
Protocols#
The engine is its own database engine on object storage. A protocol is the front door. The front door speaks the MongoDB protocol, which is why MongoDB drivers connect to it.