diff options
Diffstat (limited to 'xlators/features/marker/utils/syncdaemon/monitor.py')
| -rw-r--r-- | xlators/features/marker/utils/syncdaemon/monitor.py | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/xlators/features/marker/utils/syncdaemon/monitor.py b/xlators/features/marker/utils/syncdaemon/monitor.py index 365e91435fd..b8e9219dc47 100644 --- a/xlators/features/marker/utils/syncdaemon/monitor.py +++ b/xlators/features/marker/utils/syncdaemon/monitor.py @@ -8,11 +8,14 @@ from gconf import gconf from syncdutils import update_file class Monitor(object): + """class which spawns and manages gsyncd workers""" def __init__(self): self.state = None def set_state(self, state): + """set the state that can be used by external agents + like glusterd for status reporting""" if state == self.state: return self.state = state @@ -21,6 +24,24 @@ class Monitor(object): update_file(gconf.state_file, lambda f: f.write(state + '\n')) def monitor(self): + """the monitor loop + + Basic logic is a blantantly simple blunt heuristics: + if spawned client survives 60 secs, it's considered OK. + This servers us pretty well as it's not vulneralbe to + any kind of irregular behavior of the child... + + ... well, except for one: if children is hung up on + waiting for some event, it can survive aeons, still + will be defunct. So we tweak the above logic to + expect the worker to send us a signal within 60 secs + (in the form of closing its end of a pipe). The worker + does this when it's done with the setup stage + ready to enter the service loop (note it's the setup + stage which is vulnerable to hangs -- the full + blown worker blows up on EPIPE if the net goes down, + due to the keep-alive thread) + """ argv = sys.argv[:] for o in ('-N', '--no-daemon', '--monitor'): while o in argv: @@ -77,4 +98,5 @@ class Monitor(object): return ret def monitor(): + """oh yeah, actually Monitor is used as singleton, too""" return Monitor().monitor() |