Maintenance Mode

[cholcombe973]

Anything better we can come up with besides just disabling the cron job while maintenance is being performed on a server?

[sdandam]

Other alternatives are a) store a flag in the database b) A lock on the shared file (if read-only file system this will not work)
API need to be exposed to a) write the flag to database. b) remove the flag.
Bynar needs to re-evaluate if flag set is for too long.

[lcao0319]

We may need to following changes:

• In protobuf, add two messages: one for putting a Bynar daemon into "maintenance mode"; another for getting it out of maintenance mode.

If we go with the DB-centric way:
Use Case: Set to Maintenance

1. Upon receiving a setMaintenance message, the daemon will call the SQL DB to set the 'status' column to "maintenance" or some string.
2. Whenever the daemon accepts a request, it will then check the SQL db to see if itself is in maintenance mode, if so, log it and get out without doing anything (ignore all request).

Use Case: Unset Maintenance

1. Upon receiving a unsetMaintenance message, the daemon will call the SQL DB to set the status back to "running"(?)
2. From then on, the daemon will perform usual duties to check disks/etc as usual.