ceph/tasks/mon_thrash.py

344 lines
12 KiB
Python

"""
Monitor thrash
"""
import logging
import contextlib
import ceph_manager
import random
import time
import gevent
import json
import math
from teuthology import misc as teuthology
log = logging.getLogger(__name__)
def _get_mons(ctx):
"""
Get monitor names from the context value.
"""
mons = [f[len('mon.'):] for f in teuthology.get_mon_names(ctx)]
return mons
class MonitorThrasher:
"""
How it works::
- pick a monitor
- kill it
- wait for quorum to be formed
- sleep for 'revive_delay' seconds
- revive monitor
- wait for quorum to be formed
- sleep for 'thrash_delay' seconds
Options::
seed Seed to use on the RNG to reproduce a previous
behaviour (default: None; i.e., not set)
revive_delay Number of seconds to wait before reviving
the monitor (default: 10)
thrash_delay Number of seconds to wait in-between
test iterations (default: 0)
thrash_store Thrash monitor store before killing the monitor being thrashed (default: False)
thrash_store_probability Probability of thrashing a monitor's store
(default: 50)
thrash_many Thrash multiple monitors instead of just one. If
'maintain-quorum' is set to False, then we will
thrash up to as many monitors as there are
available. (default: False)
maintain_quorum Always maintain quorum, taking care on how many
monitors we kill during the thrashing. If we
happen to only have one or two monitors configured,
if this option is set to True, then we won't run
this task as we cannot guarantee maintenance of
quorum. Setting it to false however would allow the
task to run with as many as just one single monitor.
(default: True)
freeze_mon_probability: how often to freeze the mon instead of killing it,
in % (default: 0)
freeze_mon_duration: how many seconds to freeze the mon (default: 15)
scrub Scrub after each iteration (default: True)
Note: if 'store-thrash' is set to True, then 'maintain-quorum' must also
be set to True.
For example::
tasks:
- ceph:
- mon_thrash:
revive_delay: 20
thrash_delay: 1
thrash_store: true
thrash_store_probability: 40
seed: 31337
maintain_quorum: true
thrash_many: true
- ceph-fuse:
- workunit:
clients:
all:
- mon/workloadgen.sh
"""
def __init__(self, ctx, manager, config, logger):
self.ctx = ctx
self.manager = manager
self.manager.wait_for_clean()
self.stopping = False
self.logger = logger
self.config = config
if self.config is None:
self.config = dict()
""" Test reproducibility """
self.random_seed = self.config.get('seed', None)
if self.random_seed is None:
self.random_seed = int(time.time())
self.rng = random.Random()
self.rng.seed(int(self.random_seed))
""" Monitor thrashing """
self.revive_delay = float(self.config.get('revive_delay', 10.0))
self.thrash_delay = float(self.config.get('thrash_delay', 0.0))
self.thrash_many = self.config.get('thrash_many', False)
self.maintain_quorum = self.config.get('maintain_quorum', True)
self.scrub = self.config.get('scrub', True)
self.freeze_mon_probability = float(self.config.get('freeze_mon_probability', 10))
self.freeze_mon_duration = float(self.config.get('freeze_mon_duration', 15.0))
assert self.max_killable() > 0, \
'Unable to kill at least one monitor with the current config.'
""" Store thrashing """
self.store_thrash = self.config.get('store_thrash', False)
self.store_thrash_probability = int(
self.config.get('store_thrash_probability', 50))
if self.store_thrash:
assert self.store_thrash_probability > 0, \
'store_thrash is set, probability must be > 0'
assert self.maintain_quorum, \
'store_thrash = true must imply maintain_quorum = true'
self.thread = gevent.spawn(self.do_thrash)
def log(self, x):
"""
locally log info messages
"""
self.logger.info(x)
def do_join(self):
"""
Break out of this processes thrashing loop.
"""
self.stopping = True
self.thread.get()
def should_thrash_store(self):
"""
If allowed, indicate that we should thrash a certain percentage of
the time as determined by the store_thrash_probability value.
"""
if not self.store_thrash:
return False
return self.rng.randrange(0, 101) < self.store_thrash_probability
def thrash_store(self, mon):
"""
Thrash the monitor specified.
:param mon: monitor to thrash
"""
addr = self.ctx.ceph.conf['mon.%s' % mon]['mon addr']
self.log('thrashing mon.{id}@{addr} store'.format(id=mon, addr=addr))
out = self.manager.raw_cluster_cmd('-m', addr, 'sync', 'force')
j = json.loads(out)
assert j['ret'] == 0, \
'error forcing store sync on mon.{id}:\n{ret}'.format(
id=mon,ret=out)
def should_freeze_mon(self):
"""
Indicate that we should freeze a certain percentago of the time
as determined by the freeze_mon_probability value.
"""
return self.rng.randrange(0, 101) < self.freeze_mon_probability
def freeze_mon(self, mon):
"""
Send STOP signal to freeze the monitor.
"""
log.info('Sending STOP to mon %s', mon)
self.manager.signal_mon(mon, 19) # STOP
def unfreeze_mon(self, mon):
"""
Send CONT signal to unfreeze the monitor.
"""
log.info('Sending CONT to mon %s', mon)
self.manager.signal_mon(mon, 18) # CONT
def kill_mon(self, mon):
"""
Kill the monitor specified
"""
self.log('killing mon.{id}'.format(id=mon))
self.manager.kill_mon(mon)
def revive_mon(self, mon):
"""
Revive the monitor specified
"""
self.log('killing mon.{id}'.format(id=mon))
self.log('reviving mon.{id}'.format(id=mon))
self.manager.revive_mon(mon)
def max_killable(self):
"""
Return the maximum number of monitors we can kill.
"""
m = len(_get_mons(self.ctx))
if self.maintain_quorum:
return max(math.ceil(m/2.0)-1, 0)
else:
return m
def do_thrash(self):
"""
Cotinuously loop and thrash the monitors.
"""
self.log('start thrashing')
self.log('seed: {s}, revive delay: {r}, thrash delay: {t} '\
'thrash many: {tm}, maintain quorum: {mq} '\
'store thrash: {st}, probability: {stp} '\
'freeze mon: prob {fp} duration {fd}'.format(
s=self.random_seed,r=self.revive_delay,t=self.thrash_delay,
tm=self.thrash_many, mq=self.maintain_quorum,
st=self.store_thrash,stp=self.store_thrash_probability,
fp=self.freeze_mon_probability,fd=self.freeze_mon_duration,
))
while not self.stopping:
mons = _get_mons(self.ctx)
self.manager.wait_for_mon_quorum_size(len(mons))
self.log('making sure all monitors are in the quorum')
for m in mons:
s = self.manager.get_mon_status(m)
assert s['state'] == 'leader' or s['state'] == 'peon'
assert len(s['quorum']) == len(mons)
kill_up_to = self.rng.randrange(1, self.max_killable()+1)
mons_to_kill = self.rng.sample(mons, kill_up_to)
self.log('monitors to thrash: {m}'.format(m=mons_to_kill))
mons_to_freeze = []
for mon in mons:
if mon in mons_to_kill:
continue
if self.should_freeze_mon():
mons_to_freeze.append(mon)
self.log('monitors to freeze: {m}'.format(m=mons_to_freeze))
for mon in mons_to_kill:
self.log('thrashing mon.{m}'.format(m=mon))
""" we only thrash stores if we are maintaining quorum """
if self.should_thrash_store() and self.maintain_quorum:
self.thrash_store(mon)
self.kill_mon(mon)
if mons_to_freeze:
for mon in mons_to_freeze:
self.freeze_mon(mon)
self.log('waiting for {delay} secs to unfreeze mons'.format(
delay=self.freeze_mon_duration))
time.sleep(self.freeze_mon_duration)
for mon in mons_to_freeze:
self.unfreeze_mon(mon)
if self.maintain_quorum:
self.manager.wait_for_mon_quorum_size(len(mons)-len(mons_to_kill))
for m in mons:
if m in mons_to_kill:
continue
s = self.manager.get_mon_status(m)
assert s['state'] == 'leader' or s['state'] == 'peon'
assert len(s['quorum']) == len(mons)-len(mons_to_kill)
self.log('waiting for {delay} secs before reviving monitors'.format(
delay=self.revive_delay))
time.sleep(self.revive_delay)
for mon in mons_to_kill:
self.revive_mon(mon)
# do more freezes
if mons_to_freeze:
for mon in mons_to_freeze:
self.freeze_mon(mon)
self.log('waiting for {delay} secs to unfreeze mons'.format(
delay=self.freeze_mon_duration))
time.sleep(self.freeze_mon_duration)
for mon in mons_to_freeze:
self.unfreeze_mon(mon)
self.manager.wait_for_mon_quorum_size(len(mons))
for m in mons:
s = self.manager.get_mon_status(m)
assert s['state'] == 'leader' or s['state'] == 'peon'
assert len(s['quorum']) == len(mons)
if self.scrub:
self.log('triggering scrub')
try:
self.manager.raw_cluster_cmd('scrub')
except Exception:
log.exception("Saw exception while triggering scrub")
if self.thrash_delay > 0.0:
self.log('waiting for {delay} secs before continuing thrashing'.format(
delay=self.thrash_delay))
time.sleep(self.thrash_delay)
@contextlib.contextmanager
def task(ctx, config):
"""
Stress test the monitor by thrashing them while another task/workunit
is running.
Please refer to MonitorThrasher class for further information on the
available options.
"""
if config is None:
config = {}
assert isinstance(config, dict), \
'mon_thrash task only accepts a dict for configuration'
assert len(_get_mons(ctx)) > 2, \
'mon_thrash task requires at least 3 monitors'
log.info('Beginning mon_thrash...')
first_mon = teuthology.get_first_mon(ctx, config)
(mon,) = ctx.cluster.only(first_mon).remotes.iterkeys()
manager = ceph_manager.CephManager(
mon,
ctx=ctx,
logger=log.getChild('ceph_manager'),
)
thrash_proc = MonitorThrasher(ctx,
manager, config,
logger=log.getChild('mon_thrasher'))
try:
log.debug('Yielding')
yield
finally:
log.info('joining mon_thrasher')
thrash_proc.do_join()
mons = _get_mons(ctx)
manager.wait_for_mon_quorum_size(len(mons))