Process and agent state management about pyca HOT 5 CLOSED

While re-reading this I noticed that I should put this in writing too:

I guess if we could live with saying that it is the users responsibility to always have exactly one process of each type running, we could skip the .pid file part and go straight to the internal state database.

from pyca.

My suggestion for the processes would be anyway to have them launched separately by Systemd. That way the system can ensure that things are restarted, … If you want to use SysV-init (or whatever) instead, then let that create the pid files.

A status table, it makes sense. Though here are a few thoughts:

• The single CA state is indeed a problem. I will bring it up at the CA session at the conference. I think Opencast should support a set of states for each capture agent instead.
• Having scheduler xor capturer offline should set the state to error since it might break recordings. I'm not so sure about the ingest part (I'm thinking about the backup mode).
• Do we want a keep-alive for the state?
• All that would probably deserve another service keeping track of the ca state ;-D

from pyca.

• Single CA state: That would be the best thing, yes. With #65 That would be very easy to adapt to now.
• error: I'm not quite sure what you mean by "might break recordings." Can you elaborate?
• Keep-Alive: This would be easy to implement in #65, using timestamps and a timeout config. I think that this would indeed be a good idea: When a service fails, it might fail because of outside cirumstances, which prevent it from restarting, in which case it cannot update back to stopped.
• Agentstate service is what I did. :)

from pyca.

A keep-alive would be perfect for #48.

from pyca.

Continue keep-alive issue in #76 to keep this tidy.

from pyca.