""" Thrash mds by simulating failures """ import logging import contextlib import itertools import random import time from gevent import sleep from gevent.greenlet import Greenlet from gevent.event import Event from teuthology import misc as teuthology from tasks import ceph_manager from tasks.cephfs.filesystem import MDSCluster, Filesystem from tasks.thrasher import Thrasher log = logging.getLogger(__name__) class MDSThrasher(Thrasher, Greenlet): """ MDSThrasher:: The MDSThrasher thrashes MDSs during execution of other tasks (workunits, etc). The config is optional. Many of the config parameters are a a maximum value to use when selecting a random value from a range. To always use the maximum value, set no_random to true. The config is a dict containing some or all of: max_thrash: [default: 1] the maximum number of active MDSs per FS that will be thrashed at any given time. max_thrash_delay: [default: 30] maximum number of seconds to delay before thrashing again. max_replay_thrash_delay: [default: 4] maximum number of seconds to delay while in the replay state before thrashing. max_revive_delay: [default: 10] maximum number of seconds to delay before bringing back a thrashed MDS. randomize: [default: true] enables randomization and use the max/min values seed: [no default] seed the random number generator thrash_in_replay: [default: 0.0] likelihood that the MDS will be thrashed during replay. Value should be between 0.0 and 1.0. thrash_max_mds: [default: 0.05] likelihood that the max_mds of the mds cluster will be modified to a value [1, current) or (current, starting max_mds]. Value should be between 0.0 and 1.0. thrash_while_stopping: [default: false] thrash an MDS while there are MDS in up:stopping (because max_mds was changed and some MDS were deactivated). thrash_weights: allows specific MDSs to be thrashed more/less frequently. This option overrides anything specified by max_thrash. This option is a dict containing mds.x: weight pairs. For example, [mds.a: 0.7, mds.b: 0.3, mds.c: 0.0]. Each weight is a value from 0.0 to 1.0. Any MDSs not specified will be automatically given a weight of 0.0 (not thrashed). For a given MDS, by default the trasher delays for up to max_thrash_delay, trashes, waits for the MDS to recover, and iterates. If a non-zero weight is specified for an MDS, for each iteration the thrasher chooses whether to thrash during that iteration based on a random value [0-1] not exceeding the weight of that MDS. Examples:: The following example sets the likelihood that mds.a will be thrashed to 80%, mds.b to 20%, and other MDSs will not be thrashed. It also sets the likelihood that an MDS will be thrashed in replay to 40%. Thrash weights do not have to sum to 1. tasks: - ceph: - mds_thrash: thrash_weights: - mds.a: 0.8 - mds.b: 0.2 thrash_in_replay: 0.4 - ceph-fuse: - workunit: clients: all: [suites/fsx.sh] The following example disables randomization, and uses the max delay values: tasks: - ceph: - mds_thrash: max_thrash_delay: 10 max_revive_delay: 1 max_replay_thrash_delay: 4 """ def __init__(self, ctx, manager, config, fs, max_mds): super(MDSThrasher, self).__init__() self.config = config self.ctx = ctx self.logger = log.getChild('fs.[{f}]'.format(f = fs.name)) self.fs = fs self.manager = manager self.max_mds = max_mds self.name = 'thrasher.fs.[{f}]'.format(f = fs.name) self.stopping = Event() self.randomize = bool(self.config.get('randomize', True)) self.thrash_max_mds = float(self.config.get('thrash_max_mds', 0.05)) self.max_thrash = int(self.config.get('max_thrash', 1)) self.max_thrash_delay = float(self.config.get('thrash_delay', 120.0)) self.thrash_in_replay = float(self.config.get('thrash_in_replay', False)) assert self.thrash_in_replay >= 0.0 and self.thrash_in_replay <= 1.0, 'thrash_in_replay ({v}) must be between [0.0, 1.0]'.format( v=self.thrash_in_replay) self.max_replay_thrash_delay = float(self.config.get('max_replay_thrash_delay', 4.0)) self.max_revive_delay = float(self.config.get('max_revive_delay', 10.0)) def _run(self): try: self.do_thrash() except Exception as e: # Log exceptions here so we get the full backtrace (gevent loses them). # Also allow successful completion as gevent exception handling is a broken mess: # # 2017-02-03T14:34:01.259 CRITICAL:root: File "gevent.libev.corecext.pyx", line 367, in gevent.libev.corecext.loop.handle_error (src/gevent/libev/gevent.corecext.c:5051) # File "/home/teuthworker/src/git.ceph.com_git_teuthology_master/virtualenv/local/lib/python2.7/site-packages/gevent/hub.py", line 558, in handle_error # self.print_exception(context, type, value, tb) # File "/home/teuthworker/src/git.ceph.com_git_teuthology_master/virtualenv/local/lib/python2.7/site-packages/gevent/hub.py", line 605, in print_exception # traceback.print_exception(type, value, tb, file=errstream) # File "/usr/lib/python2.7/traceback.py", line 124, in print_exception # _print(file, 'Traceback (most recent call last):') # File "/usr/lib/python2.7/traceback.py", line 13, in _print # file.write(str+terminator) # 2017-02-03T14:34:01.261 CRITICAL:root:IOError self.set_thrasher_exception(e) self.logger.exception("exception:") # allow successful completion so gevent doesn't see an exception... def log(self, x): """Write data to the logger assigned to MDSThrasher""" self.logger.info(x) def stop(self): self.stopping.set() def kill_mds(self, mds): if self.config.get('powercycle'): (remote,) = (self.ctx.cluster.only('mds.{m}'.format(m=mds)). remotes.keys()) self.log('kill_mds on mds.{m} doing powercycle of {s}'. format(m=mds, s=remote.name)) self._assert_ipmi(remote) remote.console.power_off() else: self.ctx.daemons.get_daemon('mds', mds).stop() @staticmethod def _assert_ipmi(remote): assert remote.console.has_ipmi_credentials, ( "powercycling requested but RemoteConsole is not " "initialized. Check ipmi config.") def revive_mds(self, mds): """ Revive mds -- do an ipmpi powercycle (if indicated by the config) and then restart. """ if self.config.get('powercycle'): (remote,) = (self.ctx.cluster.only('mds.{m}'.format(m=mds)). remotes.keys()) self.log('revive_mds on mds.{m} doing powercycle of {s}'. format(m=mds, s=remote.name)) self._assert_ipmi(remote) remote.console.power_on() self.manager.make_admin_daemon_dir(self.ctx, remote) args = [] self.ctx.daemons.get_daemon('mds', mds).restart(*args) def wait_for_stable(self, rank = None, gid = None): self.log('waiting for mds cluster to stabilize...') for itercount in itertools.count(): status = self.fs.status() max_mds = status.get_fsmap(self.fs.id)['mdsmap']['max_mds'] ranks = list(status.get_ranks(self.fs.id)) stopping = sum(1 for _ in ranks if "up:stopping" == _['state']) actives = sum(1 for _ in ranks if "up:active" == _['state'] and "laggy_since" not in _) if not bool(self.config.get('thrash_while_stopping', False)) and stopping > 0: if itercount % 5 == 0: self.log('cluster is considered unstable while MDS are in up:stopping (!thrash_while_stopping)') else: if rank is not None: try: info = status.get_rank(self.fs.id, rank) if info['gid'] != gid and "up:active" == info['state']: self.log('mds.{name} has gained rank={rank}, replacing gid={gid}'.format(name = info['name'], rank = rank, gid = gid)) return status except: pass # no rank present if actives >= max_mds: # no replacement can occur! self.log("cluster has {actives} actives (max_mds is {max_mds}), no MDS can replace rank {rank}".format( actives=actives, max_mds=max_mds, rank=rank)) return status else: if actives == max_mds: self.log('mds cluster has {count} alive and active, now stable!'.format(count = actives)) return status, None if itercount > 300/2: # 5 minutes raise RuntimeError('timeout waiting for cluster to stabilize') elif itercount % 5 == 0: self.log('mds map: {status}'.format(status=status)) else: self.log('no change') sleep(2) def do_thrash(self): """ Perform the random thrashing action """ self.log('starting mds_do_thrash for fs {fs}'.format(fs = self.fs.name)) stats = { "max_mds": 0, "deactivate": 0, "kill": 0, } while not self.stopping.is_set(): delay = self.max_thrash_delay if self.randomize: delay = random.randrange(0.0, self.max_thrash_delay) if delay > 0.0: self.log('waiting for {delay} secs before thrashing'.format(delay=delay)) self.stopping.wait(delay) if self.stopping.is_set(): continue status = self.fs.status() if random.random() <= self.thrash_max_mds: max_mds = status.get_fsmap(self.fs.id)['mdsmap']['max_mds'] options = [i for i in range(1, self.max_mds + 1) if i != max_mds] if len(options) > 0: new_max_mds = random.choice(options) self.log('thrashing max_mds: %d -> %d' % (max_mds, new_max_mds)) self.fs.set_max_mds(new_max_mds) stats['max_mds'] += 1 self.wait_for_stable() count = 0 for info in status.get_ranks(self.fs.id): name = info['name'] label = 'mds.' + name rank = info['rank'] gid = info['gid'] # if thrash_weights isn't specified and we've reached max_thrash, # we're done count = count + 1 if 'thrash_weights' not in self.config and count > self.max_thrash: break weight = 1.0 if 'thrash_weights' in self.config: weight = self.config['thrash_weights'].get(label, '0.0') skip = random.randrange(0.0, 1.0) if weight <= skip: self.log('skipping thrash iteration with skip ({skip}) > weight ({weight})'.format(skip=skip, weight=weight)) continue self.log('kill {label} (rank={rank})'.format(label=label, rank=rank)) self.kill_mds(name) stats['kill'] += 1 # wait for mon to report killed mds as crashed last_laggy_since = None itercount = 0 while True: status = self.fs.status() info = status.get_mds(name) if not info: break if 'laggy_since' in info: last_laggy_since = info['laggy_since'] break if any([(f == name) for f in status.get_fsmap(self.fs.id)['mdsmap']['failed']]): break self.log( 'waiting till mds map indicates {label} is laggy/crashed, in failed state, or {label} is removed from mdsmap'.format( label=label)) itercount = itercount + 1 if itercount > 10: self.log('mds map: {status}'.format(status=status)) sleep(2) if last_laggy_since: self.log( '{label} reported laggy/crashed since: {since}'.format(label=label, since=last_laggy_since)) else: self.log('{label} down, removed from mdsmap'.format(label=label)) # wait for a standby mds to takeover and become active status = self.wait_for_stable(rank, gid) # wait for a while before restarting old active to become new # standby delay = self.max_revive_delay if self.randomize: delay = random.randrange(0.0, self.max_revive_delay) self.log('waiting for {delay} secs before reviving {label}'.format( delay=delay, label=label)) sleep(delay) self.log('reviving {label}'.format(label=label)) self.revive_mds(name) for itercount in itertools.count(): if itercount > 300/2: # 5 minutes raise RuntimeError('timeout waiting for MDS to revive') status = self.fs.status() info = status.get_mds(name) if info and info['state'] in ('up:standby', 'up:standby-replay', 'up:active'): self.log('{label} reported in {state} state'.format(label=label, state=info['state'])) break self.log( 'waiting till mds map indicates {label} is in active, standby or standby-replay'.format(label=label)) sleep(2) for stat in stats: self.log("stat['{key}'] = {value}".format(key = stat, value = stats[stat])) # don't do replay thrashing right now # for info in status.get_replays(self.fs.id): # # this might race with replay -> active transition... # if status['state'] == 'up:replay' and random.randrange(0.0, 1.0) < self.thrash_in_replay: # delay = self.max_replay_thrash_delay # if self.randomize: # delay = random.randrange(0.0, self.max_replay_thrash_delay) # sleep(delay) # self.log('kill replaying mds.{id}'.format(id=self.to_kill)) # self.kill_mds(self.to_kill) # # delay = self.max_revive_delay # if self.randomize: # delay = random.randrange(0.0, self.max_revive_delay) # # self.log('waiting for {delay} secs before reviving mds.{id}'.format( # delay=delay, id=self.to_kill)) # sleep(delay) # # self.log('revive mds.{id}'.format(id=self.to_kill)) # self.revive_mds(self.to_kill) @contextlib.contextmanager def task(ctx, config): """ Stress test the mds by thrashing while another task/workunit is running. Please refer to MDSThrasher class for further information on the available options. """ mds_cluster = MDSCluster(ctx) if config is None: config = {} assert isinstance(config, dict), \ 'mds_thrash task only accepts a dict for configuration' mdslist = list(teuthology.all_roles_of_type(ctx.cluster, 'mds')) assert len(mdslist) > 1, \ 'mds_thrash task requires at least 2 metadata servers' # choose random seed if 'seed' in config: seed = int(config['seed']) else: seed = int(time.time()) log.info('mds thrasher using random seed: {seed}'.format(seed=seed)) random.seed(seed) (first,) = ctx.cluster.only('mds.{_id}'.format(_id=mdslist[0])).remotes.keys() manager = ceph_manager.CephManager( first, ctx=ctx, logger=log.getChild('ceph_manager'), ) # make sure everyone is in active, standby, or standby-replay log.info('Wait for all MDSs to reach steady state...') status = mds_cluster.status() while True: steady = True for info in status.get_all(): state = info['state'] if state not in ('up:active', 'up:standby', 'up:standby-replay'): steady = False break if steady: break sleep(2) status = mds_cluster.status() log.info('Ready to start thrashing') manager.wait_for_clean() assert manager.is_clean() if 'cluster' not in config: config['cluster'] = 'ceph' for fs in status.get_filesystems(): thrasher = MDSThrasher(ctx, manager, config, Filesystem(ctx, fs['id']), fs['mdsmap']['max_mds']) thrasher.start() ctx.ceph[config['cluster']].thrashers.append(thrasher) try: log.debug('Yielding') yield finally: log.info('joining mds_thrasher') thrasher.stop() if thrasher.exception is not None: raise RuntimeError('error during thrashing') thrasher.join() log.info('done joining')