Ceph » CephFS

Kotresh, please take a look at this.

Discussion Summary with Patrick

1. Have a thread for each module to execute module commands. Since the finisher thread infrastructure is already in place, it's better to use one finisher thread per module.
Currently with the draft PR, there is one finisher thread per module and one generic finisher thread via which all other things like config, notify is done. This is different from the
comment 4. Both has it's pros and cons. With this approach, if any command is stuck in a python module, only that module is affected (the subsequent module commands waits) and other
module commands goes through. This is comparatively easy to implement. The comment 4's approach needs change in every python module and the effect of asynchronous nature is to be tested
as all module commands is asynchronous.

2. Add a warning if the finisher thread's queue is growing or if the it takes more than 15 secs for the single command.

3. Add extensive performance counters for osdmap, mdsmap changes, command processed (op time, command count)