# 02110-1301, USA.
-"""Tool to restart erronously downed virtual machines.
+"""Tool to restart erroneously downed virtual machines.
This program and set of classes implement a watchdog to restart
virtual machines in a Ganeti cluster that have crashed or been killed
from ganeti import opcodes
from ganeti import cli
from ganeti import luxi
+from ganeti import ssconf
+from ganeti import bdev
+from ganeti import hypervisor
+from ganeti.confd import client as confd_client
MAXTRIES = 5
return bool(utils.ReadWatcherPauseFile(constants.WATCHER_PAUSEFILE))
-def EnsureDaemon(name):
- """Check for and start daemon if not alive.
+def StartNodeDaemons():
+ """Start all the daemons that should be running on all nodes.
"""
- result = utils.RunCmd([constants.DAEMON_UTIL, "check-and-start", name])
- if result.failed:
- logging.error("Can't start daemon '%s', failure %s, output: %s",
- name, result.fail_reason, result.output)
- return False
+ # on master or not, try to start the node daemon
+ utils.EnsureDaemon(constants.NODED)
+ # start confd as well. On non candidates it will be in disabled mode.
+ utils.EnsureDaemon(constants.CONFD)
- return True
+
+def RunWatcherHooks():
+ """Run the watcher hooks.
+
+ """
+ hooks_dir = utils.PathJoin(constants.HOOKS_BASE_DIR,
+ constants.HOOKS_NAME_WATCHER)
+ if not os.path.isdir(hooks_dir):
+ return
+
+ try:
+ results = utils.RunParts(hooks_dir)
+ except Exception, msg: # pylint: disable-msg=W0703
+ logging.critical("RunParts %s failed: %s", hooks_dir, msg)
+
+ for (relname, status, runresult) in results:
+ if status == constants.RUNPARTS_SKIP:
+ logging.debug("Watcher hook %s: skipped", relname)
+ elif status == constants.RUNPARTS_ERR:
+ logging.warning("Watcher hook %s: error (%s)", relname, runresult)
+ elif status == constants.RUNPARTS_RUN:
+ if runresult.failed:
+ logging.warning("Watcher hook %s: failed (exit: %d) (output: %s)",
+ relname, runresult.exit_code, runresult.output)
+ else:
+ logging.debug("Watcher hook %s: success (output: %s)", relname,
+ runresult.output)
+
+
+class NodeMaintenance(object):
+ """Talks to confd daemons and possible shutdown instances/drbd devices.
+
+ """
+ def __init__(self):
+ self.store_cb = confd_client.StoreResultCallback()
+ self.filter_cb = confd_client.ConfdFilterCallback(self.store_cb)
+ self.confd_client = confd_client.GetConfdClient(self.filter_cb)
+
+ @staticmethod
+ def ShouldRun():
+ """Checks whether node maintenance should run.
+
+ """
+ try:
+ return ssconf.SimpleStore().GetMaintainNodeHealth()
+ except errors.ConfigurationError, err:
+ logging.error("Configuration error, not activating node maintenance: %s",
+ err)
+ return False
+
+ @staticmethod
+ def GetRunningInstances():
+ """Compute list of hypervisor/running instances.
+
+ """
+ hyp_list = ssconf.SimpleStore().GetHypervisorList()
+ results = []
+ for hv_name in hyp_list:
+ try:
+ hv = hypervisor.GetHypervisor(hv_name)
+ ilist = hv.ListInstances()
+ results.extend([(iname, hv_name) for iname in ilist])
+ except: # pylint: disable-msg=W0702
+ logging.error("Error while listing instances for hypervisor %s",
+ hv_name, exc_info=True)
+ return results
+
+ @staticmethod
+ def GetUsedDRBDs():
+ """Get list of used DRBD minors.
+
+ """
+ return bdev.DRBD8.GetUsedDevs().keys()
+
+ @classmethod
+ def DoMaintenance(cls, role):
+ """Maintain the instance list.
+
+ """
+ if role == constants.CONFD_NODE_ROLE_OFFLINE:
+ inst_running = cls.GetRunningInstances()
+ cls.ShutdownInstances(inst_running)
+ drbd_running = cls.GetUsedDRBDs()
+ cls.ShutdownDRBD(drbd_running)
+ else:
+ logging.debug("Not doing anything for role %s", role)
+
+ @staticmethod
+ def ShutdownInstances(inst_running):
+ """Shutdown running instances.
+
+ """
+ names_running = set([i[0] for i in inst_running])
+ if names_running:
+ logging.info("Following instances should not be running,"
+ " shutting them down: %s", utils.CommaJoin(names_running))
+ # this dictionary will collapse duplicate instance names (only
+ # xen pvm/vhm) into a single key, which is fine
+ i2h = dict(inst_running)
+ for name in names_running:
+ hv_name = i2h[name]
+ hv = hypervisor.GetHypervisor(hv_name)
+ hv.StopInstance(None, force=True, name=name)
+
+ @staticmethod
+ def ShutdownDRBD(drbd_running):
+ """Shutdown active DRBD devices.
+
+ """
+ if drbd_running:
+ logging.info("Following DRBD minors should not be active,"
+ " shutting them down: %s", utils.CommaJoin(drbd_running))
+ for minor in drbd_running:
+ # pylint: disable-msg=W0212
+ # using the private method as is, pending enhancements to the DRBD
+ # interface
+ bdev.DRBD8._ShutdownAll(minor)
+
+ def Exec(self):
+ """Check node status versus cluster desired state.
+
+ """
+ my_name = utils.HostInfo().name
+ req = confd_client.ConfdClientRequest(type=
+ constants.CONFD_REQ_NODE_ROLE_BYNAME,
+ query=my_name)
+ self.confd_client.SendRequest(req, async=False, coverage=-1)
+ timed_out, _, _ = self.confd_client.WaitForReply(req.rsalt)
+ if not timed_out:
+ # should have a valid response
+ status, result = self.store_cb.GetResponse(req.rsalt)
+ assert status, "Missing result but received replies"
+ if not self.filter_cb.consistent[req.rsalt]:
+ logging.warning("Inconsistent replies, not doing anything")
+ return
+ self.DoMaintenance(result.server_reply.answer)
+ else:
+ logging.warning("Confd query timed out, cannot do maintenance actions")
class WatcherState(object):
"""Interface to a state file recording restart attempts.
"""
- def __init__(self):
+ def __init__(self, statefile):
"""Open, lock, read and parse the file.
- Raises exception on lock contention.
+ @type statefile: file
+ @param statefile: State file object
"""
- # The two-step dance below is necessary to allow both opening existing
- # file read/write and creating if not existing. Vanilla open will truncate
- # an existing file -or- allow creating if not existing.
- fd = os.open(constants.WATCHER_STATEFILE, os.O_RDWR | os.O_CREAT)
- self.statefile = os.fdopen(fd, 'w+')
-
- utils.LockFile(self.statefile.fileno())
+ self.statefile = statefile
try:
state_data = self.statefile.read()
class Watcher(object):
- """Encapsulate the logic for restarting erronously halted virtual machines.
+ """Encapsulate the logic for restarting erroneously halted virtual machines.
The calling program should periodically instantiate me and call Run().
This will traverse the list of instances, and make up to MAXTRIES attempts
logging.exception("Error while activating disks")
+def OpenStateFile(path):
+ """Opens the state file and acquires a lock on it.
+
+ @type path: string
+ @param path: Path to state file
+
+ """
+ # The two-step dance below is necessary to allow both opening existing
+ # file read/write and creating if not existing. Vanilla open will truncate
+ # an existing file -or- allow creating if not existing.
+ statefile_fd = os.open(path, os.O_RDWR | os.O_CREAT)
+
+ # Try to acquire lock on state file. If this fails, another watcher instance
+ # might already be running or another program is temporarily blocking the
+ # watcher from running.
+ try:
+ utils.LockFile(statefile_fd)
+ except errors.LockError, err:
+ logging.error("Can't acquire lock on state file %s: %s", path, err)
+ return None
+
+ return os.fdopen(statefile_fd, "w+")
+
+
def ParseOptions():
"""Parse the command line options.
logging.debug("Pause has been set, exiting")
sys.exit(constants.EXIT_SUCCESS)
+ statefile = OpenStateFile(constants.WATCHER_STATEFILE)
+ if not statefile:
+ sys.exit(constants.EXIT_FAILURE)
+
update_file = False
try:
- # on master or not, try to start the node dameon
- EnsureDaemon(constants.NODED)
- # start confd as well. On non candidates it will be in disabled mode.
- EnsureDaemon(constants.CONFD)
-
- notepad = WatcherState()
+ StartNodeDaemons()
+ RunWatcherHooks()
+ # run node maintenance in all cases, even if master, so that old
+ # masters can be properly cleaned up too
+ if NodeMaintenance.ShouldRun():
+ NodeMaintenance().Exec()
+
+ notepad = WatcherState(statefile)
try:
try:
client = cli.GetClient()
except luxi.NoMasterError, err:
logging.warning("Master seems to be down (%s), trying to restart",
str(err))
- if not EnsureDaemon(constants.MASTERD):
+ if not utils.EnsureDaemon(constants.MASTERD):
logging.critical("Can't start the master, exiting")
sys.exit(constants.EXIT_FAILURE)
# else retry the connection
client = cli.GetClient()
# we are on master now
- EnsureDaemon(constants.RAPI)
+ utils.EnsureDaemon(constants.RAPI)
try:
watcher = Watcher(options, notepad)
except errors.JobQueueDrainError:
logging.error("Job queue is drained, can't maintain cluster state")
except Exception, err:
- logging.error(str(err), exc_info=True)
+ logging.exception(str(err))
sys.exit(constants.EXIT_FAILURE)
projects / ganeti-local / blobdiff