root / lib / watcher / __init__.py @ 8f07dc0d
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#
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# Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Google Inc.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301, USA.
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"""Tool to restart erroneously downed virtual machines.
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This program and set of classes implement a watchdog to restart
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virtual machines in a Ganeti cluster that have crashed or been killed
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by a node reboot. Run from cron or similar.
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"""
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import os |
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import os.path |
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import sys |
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import time |
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import logging |
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from optparse import OptionParser |
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from ganeti import utils |
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from ganeti import constants |
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from ganeti import compat |
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from ganeti import errors |
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from ganeti import opcodes |
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from ganeti import cli |
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from ganeti import luxi |
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from ganeti import rapi |
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from ganeti import netutils |
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import ganeti.rapi.client # pylint: disable-msg=W0611 |
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from ganeti.watcher import nodemaint |
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from ganeti.watcher import state |
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MAXTRIES = 5
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# Global LUXI client object
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client = None
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BAD_STATES = frozenset([
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constants.INSTST_ERRORDOWN, |
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]) |
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HELPLESS_STATES = frozenset([
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constants.INSTST_NODEDOWN, |
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constants.INSTST_NODEOFFLINE, |
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]) |
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NOTICE = "NOTICE"
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ERROR = "ERROR"
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class NotMasterError(errors.GenericError): |
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"""Exception raised when this host is not the master."""
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def ShouldPause(): |
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"""Check whether we should pause.
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"""
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return bool(utils.ReadWatcherPauseFile(constants.WATCHER_PAUSEFILE)) |
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def StartNodeDaemons(): |
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"""Start all the daemons that should be running on all nodes.
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"""
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# on master or not, try to start the node daemon
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utils.EnsureDaemon(constants.NODED) |
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# start confd as well. On non candidates it will be in disabled mode.
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utils.EnsureDaemon(constants.CONFD) |
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def RunWatcherHooks(): |
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"""Run the watcher hooks.
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"""
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hooks_dir = utils.PathJoin(constants.HOOKS_BASE_DIR, |
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constants.HOOKS_NAME_WATCHER) |
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if not os.path.isdir(hooks_dir): |
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return
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try:
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results = utils.RunParts(hooks_dir) |
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except Exception: # pylint: disable-msg=W0703 |
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logging.exception("RunParts %s failed: %s", hooks_dir)
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return
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for (relname, status, runresult) in results: |
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if status == constants.RUNPARTS_SKIP:
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logging.debug("Watcher hook %s: skipped", relname)
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elif status == constants.RUNPARTS_ERR:
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logging.warning("Watcher hook %s: error (%s)", relname, runresult)
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elif status == constants.RUNPARTS_RUN:
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if runresult.failed:
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logging.warning("Watcher hook %s: failed (exit: %d) (output: %s)",
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relname, runresult.exit_code, runresult.output) |
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else:
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logging.debug("Watcher hook %s: success (output: %s)", relname,
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runresult.output) |
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else:
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raise errors.ProgrammerError("Unknown status %s returned by RunParts", |
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status) |
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class Instance(object): |
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"""Abstraction for a Virtual Machine instance.
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"""
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def __init__(self, name, status, autostart, snodes): |
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self.name = name
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self.status = status
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self.autostart = autostart
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self.snodes = snodes
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def Restart(self): |
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"""Encapsulates the start of an instance.
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"""
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op = opcodes.OpInstanceStartup(instance_name=self.name, force=False) |
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cli.SubmitOpCode(op, cl=client) |
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def ActivateDisks(self): |
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"""Encapsulates the activation of all disks of an instance.
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"""
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op = opcodes.OpInstanceActivateDisks(instance_name=self.name)
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cli.SubmitOpCode(op, cl=client) |
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def GetClusterData(): |
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"""Get a list of instances on this cluster.
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"""
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op1_fields = ["name", "status", "admin_state", "snodes"] |
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op1 = opcodes.OpInstanceQuery(output_fields=op1_fields, names=[], |
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use_locking=True)
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op2_fields = ["name", "bootid", "offline"] |
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op2 = opcodes.OpNodeQuery(output_fields=op2_fields, names=[], |
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use_locking=True)
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job_id = client.SubmitJob([op1, op2]) |
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all_results = cli.PollJob(job_id, cl=client, feedback_fn=logging.debug) |
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logging.debug("Got data from cluster, writing instance status file")
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result = all_results[0]
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smap = {} |
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instances = {} |
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_UpdateInstanceStatus(client, constants.INSTANCE_STATUS_FILE) |
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for fields in result: |
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(name, status, autostart, snodes) = fields |
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# update the secondary node map
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for node in snodes: |
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if node not in smap: |
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smap[node] = [] |
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smap[node].append(name) |
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instances[name] = Instance(name, status, autostart, snodes) |
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nodes = dict([(name, (bootid, offline))
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for name, bootid, offline in all_results[1]]) |
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client.ArchiveJob(job_id) |
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return instances, nodes, smap
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class Watcher(object): |
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"""Encapsulate the logic for restarting erroneously halted virtual machines.
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The calling program should periodically instantiate me and call Run().
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This will traverse the list of instances, and make up to MAXTRIES attempts
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to restart machines that are down.
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"""
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def __init__(self, opts, notepad): |
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self.notepad = notepad
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master = client.QueryConfigValues(["master_node"])[0] |
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if master != netutils.Hostname.GetSysName():
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raise NotMasterError("This is not the master node") |
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# first archive old jobs
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self.ArchiveJobs(opts.job_age)
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# and only then submit new ones
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self.instances, self.bootids, self.smap = GetClusterData() |
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self.started_instances = set() |
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self.opts = opts
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def Run(self): |
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"""Watcher run sequence.
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"""
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notepad = self.notepad
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self.CheckInstances(notepad)
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self.CheckDisks(notepad)
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self.VerifyDisks()
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@staticmethod
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def ArchiveJobs(age): |
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"""Archive old jobs.
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"""
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arch_count, left_count = client.AutoArchiveJobs(age) |
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logging.debug("Archived %s jobs, left %s", arch_count, left_count)
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def CheckDisks(self, notepad): |
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"""Check all nodes for restarted ones.
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"""
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check_nodes = [] |
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for name, (new_id, offline) in self.bootids.iteritems(): |
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old = notepad.GetNodeBootID(name) |
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if new_id is None: |
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# Bad node, not returning a boot id
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if not offline: |
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logging.debug("Node %s missing boot id, skipping secondary checks",
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name) |
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continue
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if old != new_id:
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# Node's boot ID has changed, proably through a reboot.
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check_nodes.append(name) |
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if check_nodes:
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# Activate disks for all instances with any of the checked nodes as a
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# secondary node.
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for node in check_nodes: |
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if node not in self.smap: |
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continue
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for instance_name in self.smap[node]: |
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instance = self.instances[instance_name]
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if not instance.autostart: |
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logging.info(("Skipping disk activation for non-autostart"
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" instance %s"), instance.name)
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continue
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if instance.name in self.started_instances: |
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# we already tried to start the instance, which should have
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# activated its drives (if they can be at all)
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logging.debug("Skipping disk activation for instance %s, as"
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" it was already started", instance.name)
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continue
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try:
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logging.info("Activating disks for instance %s", instance.name)
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instance.ActivateDisks() |
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except Exception: # pylint: disable-msg=W0703 |
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logging.exception("Error while activating disks for instance %s",
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instance.name) |
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# Keep changed boot IDs
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for name in check_nodes: |
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notepad.SetNodeBootID(name, self.bootids[name][0]) |
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def CheckInstances(self, notepad): |
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"""Make a pass over the list of instances, restarting downed ones.
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"""
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notepad.MaintainInstanceList(self.instances.keys())
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for instance in self.instances.values(): |
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if instance.status in BAD_STATES: |
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n = notepad.NumberOfRestartAttempts(instance.name) |
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if n > MAXTRIES:
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logging.warning("Not restarting instance %s, retries exhausted",
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instance.name) |
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continue
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elif n < MAXTRIES:
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last = " (Attempt #%d)" % (n + 1) |
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else:
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notepad.RecordRestartAttempt(instance.name) |
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logging.error("Could not restart %s after %d attempts, giving up",
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instance.name, MAXTRIES) |
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continue
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try:
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logging.info("Restarting %s%s", instance.name, last)
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instance.Restart() |
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self.started_instances.add(instance.name)
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except Exception: # pylint: disable-msg=W0703 |
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logging.exception("Error while restarting instance %s",
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instance.name) |
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notepad.RecordRestartAttempt(instance.name) |
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elif instance.status in HELPLESS_STATES: |
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if notepad.NumberOfRestartAttempts(instance.name):
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notepad.RemoveInstance(instance.name) |
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else:
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if notepad.NumberOfRestartAttempts(instance.name):
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notepad.RemoveInstance(instance.name) |
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logging.info("Restart of %s succeeded", instance.name)
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def _CheckForOfflineNodes(self, instance): |
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"""Checks if given instances has any secondary in offline status.
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@param instance: The instance object
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@return: True if any of the secondary is offline, False otherwise
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"""
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bootids = [] |
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for node in instance.snodes: |
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bootids.append(self.bootids[node])
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return compat.any(offline for (_, offline) in bootids) |
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def VerifyDisks(self): |
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"""Run gnt-cluster verify-disks.
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"""
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job_id = client.SubmitJob([opcodes.OpClusterVerifyDisks()]) |
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result = cli.PollJob(job_id, cl=client, feedback_fn=logging.debug)[0]
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client.ArchiveJob(job_id) |
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# Keep track of submitted jobs
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jex = cli.JobExecutor(cl=client, feedback_fn=logging.debug) |
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archive_jobs = set()
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for (status, job_id) in result[constants.JOB_IDS_KEY]: |
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jex.AddJobId(None, status, job_id)
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if status:
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archive_jobs.add(job_id) |
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offline_disk_instances = set()
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for (status, result) in jex.GetResults(): |
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if not status: |
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logging.error("Verify-disks job failed: %s", result)
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continue
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((_, instances, _), ) = result |
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offline_disk_instances.update(instances) |
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for job_id in archive_jobs: |
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client.ArchiveJob(job_id) |
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if not offline_disk_instances: |
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# nothing to do
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logging.debug("verify-disks reported no offline disks, nothing to do")
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return
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logging.debug("Will activate disks for instance(s) %s",
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utils.CommaJoin(offline_disk_instances)) |
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# we submit only one job, and wait for it. not optimal, but spams
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# less the job queue
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job = [] |
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for name in offline_disk_instances: |
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instance = self.instances[name]
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if (instance.status in HELPLESS_STATES or |
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self._CheckForOfflineNodes(instance)):
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logging.info("Skip instance %s because it is in helpless state or has"
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" one offline secondary", name)
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continue
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job.append(opcodes.OpInstanceActivateDisks(instance_name=name)) |
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if job:
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job_id = cli.SendJob(job, cl=client) |
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try:
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cli.PollJob(job_id, cl=client, feedback_fn=logging.debug) |
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except Exception: # pylint: disable-msg=W0703 |
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logging.exception("Error while activating disks")
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def IsRapiResponding(hostname): |
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"""Connects to RAPI port and does a simple test.
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Connects to RAPI port of hostname and does a simple test. At this time, the
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test is GetVersion.
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@type hostname: string
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@param hostname: hostname of the node to connect to.
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@rtype: bool
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@return: Whether RAPI is working properly
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"""
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curl_config = rapi.client.GenericCurlConfig() |
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rapi_client = rapi.client.GanetiRapiClient(hostname, |
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curl_config_fn=curl_config) |
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try:
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master_version = rapi_client.GetVersion() |
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except rapi.client.CertificateError, err:
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logging.warning("RAPI certificate error: %s", err)
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return False |
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except rapi.client.GanetiApiError, err:
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logging.warning("RAPI error: %s", err)
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return False |
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else:
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logging.debug("Reported RAPI version %s", master_version)
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return master_version == constants.RAPI_VERSION
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def ParseOptions(): |
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"""Parse the command line options.
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@return: (options, args) as from OptionParser.parse_args()
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"""
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parser = OptionParser(description="Ganeti cluster watcher",
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usage="%prog [-d]",
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version="%%prog (ganeti) %s" %
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constants.RELEASE_VERSION) |
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parser.add_option(cli.DEBUG_OPT) |
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parser.add_option("-A", "--job-age", dest="job_age", default=6 * 3600, |
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help="Autoarchive jobs older than this age (default"
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" 6 hours)")
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parser.add_option("--ignore-pause", dest="ignore_pause", default=False, |
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action="store_true", help="Ignore cluster pause setting") |
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options, args = parser.parse_args() |
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options.job_age = cli.ParseTimespec(options.job_age) |
431 |
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if args:
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parser.error("No arguments expected")
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return (options, args)
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def _UpdateInstanceStatus(cl, filename): |
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"""Get a list of instances on this cluster.
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@todo: Think about doing this per nodegroup, too
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"""
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op = opcodes.OpInstanceQuery(output_fields=["name", "status"], names=[], |
445 |
use_locking=True)
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job_id = cl.SubmitJob([op]) |
447 |
(result, ) = cli.PollJob(job_id, cl=cl, feedback_fn=logging.debug) |
448 |
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cl.ArchiveJob(job_id) |
450 |
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logging.debug("Got instance data, writing status file %s", filename)
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utils.WriteFile(filename, data="".join("%s %s\n" % (name, status) |
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for (name, status) in result)) |
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@rapi.client.UsesRapiClient
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def Main(): |
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"""Main function.
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460 |
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"""
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global client # pylint: disable-msg=W0603 |
463 |
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(options, _) = ParseOptions() |
465 |
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utils.SetupLogging(constants.LOG_WATCHER, sys.argv[0],
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debug=options.debug, stderr_logging=options.debug) |
468 |
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if ShouldPause() and not options.ignore_pause: |
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logging.debug("Pause has been set, exiting")
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return constants.EXIT_SUCCESS
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statefile = \ |
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state.OpenStateFile(constants.WATCHER_STATEFILE) |
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if not statefile: |
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return constants.EXIT_FAILURE
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477 |
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update_file = False
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try:
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StartNodeDaemons() |
481 |
RunWatcherHooks() |
482 |
# run node maintenance in all cases, even if master, so that old
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# masters can be properly cleaned up too
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if nodemaint.NodeMaintenance.ShouldRun():
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nodemaint.NodeMaintenance().Exec() |
486 |
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notepad = state.WatcherState(statefile) |
488 |
try:
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try:
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client = cli.GetClient() |
491 |
except errors.OpPrereqError:
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# this is, from cli.GetClient, a not-master case
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logging.debug("Not on master, exiting")
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update_file = True
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return constants.EXIT_SUCCESS
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except luxi.NoMasterError, err:
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logging.warning("Master seems to be down (%s), trying to restart",
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str(err))
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if not utils.EnsureDaemon(constants.MASTERD): |
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logging.critical("Can't start the master, exiting")
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return constants.EXIT_FAILURE
|
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# else retry the connection
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client = cli.GetClient() |
504 |
|
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# we are on master now
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utils.EnsureDaemon(constants.RAPI) |
507 |
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# If RAPI isn't responding to queries, try one restart.
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logging.debug("Attempting to talk with RAPI.")
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if not IsRapiResponding(constants.IP4_ADDRESS_LOCALHOST): |
511 |
logging.warning("Couldn't get answer from Ganeti RAPI daemon."
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" Restarting Ganeti RAPI.")
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utils.StopDaemon(constants.RAPI) |
514 |
utils.EnsureDaemon(constants.RAPI) |
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logging.debug("Second attempt to talk with RAPI")
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if not IsRapiResponding(constants.IP4_ADDRESS_LOCALHOST): |
517 |
logging.fatal("RAPI is not responding. Please investigate.")
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logging.debug("Successfully talked to RAPI.")
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|
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try:
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watcher = Watcher(options, notepad) |
522 |
except errors.ConfigurationError:
|
523 |
# Just exit if there's no configuration
|
524 |
update_file = True
|
525 |
return constants.EXIT_SUCCESS
|
526 |
|
527 |
watcher.Run() |
528 |
update_file = True
|
529 |
|
530 |
finally:
|
531 |
if update_file:
|
532 |
notepad.Save(constants.WATCHER_STATEFILE) |
533 |
else:
|
534 |
logging.debug("Not updating status file due to failure")
|
535 |
except SystemExit: |
536 |
raise
|
537 |
except NotMasterError:
|
538 |
logging.debug("Not master, exiting")
|
539 |
return constants.EXIT_NOTMASTER
|
540 |
except errors.ResolverError, err:
|
541 |
logging.error("Cannot resolve hostname '%s', exiting", err.args[0]) |
542 |
return constants.EXIT_NODESETUP_ERROR
|
543 |
except errors.JobQueueFull:
|
544 |
logging.error("Job queue is full, can't query cluster state")
|
545 |
except errors.JobQueueDrainError:
|
546 |
logging.error("Job queue is drained, can't maintain cluster state")
|
547 |
except Exception, err: |
548 |
logging.exception(str(err))
|
549 |
return constants.EXIT_FAILURE
|
550 |
|
551 |
return constants.EXIT_SUCCESS
|