""" Teuthology task for exercising CephFS client recovery """ import logging from textwrap import dedent import time import distutils.version as version import re import os from teuthology.orchestra.run import CommandFailedError, ConnectionLostError from tasks.cephfs.cephfs_test_case import CephFSTestCase from teuthology.packaging import get_package_version log = logging.getLogger(__name__) # Arbitrary timeouts for operations involving restarting # an MDS or waiting for it to come up MDS_RESTART_GRACE = 60 class TestClientRecovery(CephFSTestCase): REQUIRE_KCLIENT_REMOTE = True REQUIRE_ONE_CLIENT_REMOTE = True CLIENTS_REQUIRED = 2 LOAD_SETTINGS = ["mds_session_timeout", "mds_reconnect_timeout", "ms_max_backoff"] # Environment references mds_session_timeout = None mds_reconnect_timeout = None ms_max_backoff = None def test_basic(self): # Check that two clients come up healthy and see each others' files # ===================================================== self.mount_a.create_files() self.mount_a.check_files() self.mount_a.umount_wait() self.mount_b.check_files() self.mount_a.mount() self.mount_a.wait_until_mounted() # Check that the admin socket interface is correctly reporting # two sessions # ===================================================== ls_data = self._session_list() self.assert_session_count(2, ls_data) self.assertSetEqual( set([l['id'] for l in ls_data]), {self.mount_a.get_global_id(), self.mount_b.get_global_id()} ) def test_restart(self): # Check that after an MDS restart both clients reconnect and continue # to handle I/O # ===================================================== self.fs.mds_fail_restart() self.fs.wait_for_state('up:active', timeout=MDS_RESTART_GRACE) self.mount_a.create_destroy() self.mount_b.create_destroy() def _session_num_caps(self, client_id): ls_data = self.fs.mds_asok(['session', 'ls']) return int(self._session_by_id(ls_data).get(client_id, {'num_caps': None})['num_caps']) def test_reconnect_timeout(self): # Reconnect timeout # ================= # Check that if I stop an MDS and a client goes away, the MDS waits # for the reconnect period self.fs.mds_stop() self.fs.mds_fail() mount_a_client_id = self.mount_a.get_global_id() self.mount_a.umount_wait(force=True) self.fs.mds_restart() self.fs.wait_for_state('up:reconnect', reject='up:active', timeout=MDS_RESTART_GRACE) ls_data = self._session_list() self.assert_session_count(2, ls_data) # The session for the dead client should have the 'reconnect' flag set self.assertTrue(self.get_session(mount_a_client_id)['reconnecting']) # Wait for the reconnect state to clear, this should take the # reconnect timeout period. in_reconnect_for = self.fs.wait_for_state('up:active', timeout=self.mds_reconnect_timeout * 2) # Check that the period we waited to enter active is within a factor # of two of the reconnect timeout. self.assertGreater(in_reconnect_for, self.mds_reconnect_timeout / 2, "Should have been in reconnect phase for {0} but only took {1}".format( self.mds_reconnect_timeout, in_reconnect_for )) self.assert_session_count(1) # Check that the client that timed out during reconnect can # mount again and do I/O self.mount_a.mount() self.mount_a.wait_until_mounted() self.mount_a.create_destroy() self.assert_session_count(2) def test_reconnect_eviction(self): # Eviction during reconnect # ========================= self.fs.mds_stop() self.fs.mds_fail() mount_a_client_id = self.mount_a.get_global_id() self.mount_a.umount_wait(force=True) self.fs.mds_restart() # Enter reconnect phase self.fs.wait_for_state('up:reconnect', reject='up:active', timeout=MDS_RESTART_GRACE) self.assert_session_count(2) # Evict the stuck client self.fs.mds_asok(['session', 'evict', "%s" % mount_a_client_id]) self.assert_session_count(1) # Observe that we proceed to active phase without waiting full reconnect timeout evict_til_active = self.fs.wait_for_state('up:active', timeout=MDS_RESTART_GRACE) # Once we evict the troublemaker, the reconnect phase should complete # in well under the reconnect timeout. self.assertLess(evict_til_active, self.mds_reconnect_timeout * 0.5, "reconnect did not complete soon enough after eviction, took {0}".format( evict_til_active )) # Bring the client back self.mount_a.mount() self.mount_a.wait_until_mounted() self.mount_a.create_destroy() def test_stale_caps(self): # Capability release from stale session # ===================================== cap_holder = self.mount_a.open_background() # Wait for the file to be visible from another client, indicating # that mount_a has completed its network ops self.mount_b.wait_for_visible() # Simulate client death self.mount_a.kill() try: # Now, after mds_session_timeout seconds, the waiter should # complete their operation when the MDS marks the holder's # session stale. cap_waiter = self.mount_b.write_background() a = time.time() cap_waiter.wait() b = time.time() # Should have succeeded self.assertEqual(cap_waiter.exitstatus, 0) cap_waited = b - a log.info("cap_waiter waited {0}s".format(cap_waited)) self.assertTrue(self.mds_session_timeout / 2.0 <= cap_waited <= self.mds_session_timeout * 2.0, "Capability handover took {0}, expected approx {1}".format( cap_waited, self.mds_session_timeout )) cap_holder.stdin.close() try: cap_holder.wait() except (CommandFailedError, ConnectionLostError): # We killed it (and possibly its node), so it raises an error pass finally: # teardown() doesn't quite handle this case cleanly, so help it out self.mount_a.kill_cleanup() self.mount_a.mount() self.mount_a.wait_until_mounted() def test_evicted_caps(self): # Eviction while holding a capability # =================================== # Take out a write capability on a file on client A, # and then immediately kill it. cap_holder = self.mount_a.open_background() mount_a_client_id = self.mount_a.get_global_id() # Wait for the file to be visible from another client, indicating # that mount_a has completed its network ops self.mount_b.wait_for_visible() # Simulate client death self.mount_a.kill() try: # The waiter should get stuck waiting for the capability # held on the MDS by the now-dead client A cap_waiter = self.mount_b.write_background() time.sleep(5) self.assertFalse(cap_waiter.finished) self.fs.mds_asok(['session', 'evict', "%s" % mount_a_client_id]) # Now, because I evicted the old holder of the capability, it should # immediately get handed over to the waiter a = time.time() cap_waiter.wait() b = time.time() cap_waited = b - a log.info("cap_waiter waited {0}s".format(cap_waited)) # This is the check that it happened 'now' rather than waiting # for the session timeout self.assertLess(cap_waited, self.mds_session_timeout / 2.0, "Capability handover took {0}, expected less than {1}".format( cap_waited, self.mds_session_timeout / 2.0 )) cap_holder.stdin.close() try: cap_holder.wait() except (CommandFailedError, ConnectionLostError): # We killed it (and possibly its node), so it raises an error pass finally: self.mount_a.kill_cleanup() self.mount_a.mount() self.mount_a.wait_until_mounted() def test_trim_caps(self): # Trim capability when reconnecting MDS # =================================== count = 500 # Create lots of files for i in range(count): self.mount_a.run_shell(["sudo", "touch", "f{0}".format(i)]) # Populate mount_b's cache self.mount_b.run_shell(["sudo", "ls"]) client_id = self.mount_b.get_global_id() num_caps = self._session_num_caps(client_id) self.assertGreaterEqual(num_caps, count) # Restart MDS. client should trim its cache when reconnecting to the MDS self.fs.mds_fail_restart() self.fs.wait_for_state('up:active', timeout=MDS_RESTART_GRACE) num_caps = self._session_num_caps(client_id) self.assertLess(num_caps, count, "should have less than {0} capabilities, have {1}".format( count, num_caps )) def test_network_death(self): """ Simulate software freeze or temporary network failure. Check that the client blocks I/O during failure, and completes I/O after failure. """ # We only need one client self.mount_b.umount_wait() # Initially our one client session should be visible client_id = self.mount_a.get_global_id() ls_data = self._session_list() self.assert_session_count(1, ls_data) self.assertEqual(ls_data[0]['id'], client_id) self.assert_session_state(client_id, "open") # ...and capable of doing I/O without blocking self.mount_a.create_files() # ...but if we turn off the network self.fs.set_clients_block(True) # ...and try and start an I/O write_blocked = self.mount_a.write_background() # ...then it should block self.assertFalse(write_blocked.finished) self.assert_session_state(client_id, "open") time.sleep(self.mds_session_timeout * 1.5) # Long enough for MDS to consider session stale self.assertFalse(write_blocked.finished) self.assert_session_state(client_id, "stale") # ...until we re-enable I/O self.fs.set_clients_block(False) # ...when it should complete promptly a = time.time() write_blocked.wait() b = time.time() recovery_time = b - a log.info("recovery time: {0}".format(recovery_time)) self.assertLess(recovery_time, self.ms_max_backoff * 2) self.assert_session_state(client_id, "open") def test_filelock(self): """ Check that file lock doesn't get lost after an MDS restart """ a_version_str = get_package_version(self.mount_a.client_remote, "fuse") b_version_str = get_package_version(self.mount_b.client_remote, "fuse") flock_version_str = "2.9" version_regex = re.compile(r"[0-9\.]+") a_result = version_regex.match(a_version_str) self.assertTrue(a_result) b_result = version_regex.match(b_version_str) self.assertTrue(b_result) a_version = version.StrictVersion(a_result.group()) b_version = version.StrictVersion(b_result.group()) flock_version=version.StrictVersion(flock_version_str) flockable = False if (a_version >= flock_version and b_version >= flock_version): log.info("testing flock locks") flockable = True else: log.info("not testing flock locks, machines have versions {av} and {bv}".format( av=a_version_str,bv=b_version_str)) lock_holder = self.mount_a.lock_background(do_flock=flockable) self.mount_b.wait_for_visible("background_file-2") self.mount_b.check_filelock(do_flock=flockable) self.fs.mds_fail_restart() self.fs.wait_for_state('up:active', timeout=MDS_RESTART_GRACE) self.mount_b.check_filelock(do_flock=flockable) # Tear down the background process lock_holder.stdin.close() try: lock_holder.wait() except (CommandFailedError, ConnectionLostError): # We killed it, so it raises an error pass def test_fsync(self): """ That calls to fsync guarantee visibility of metadata to another client immediately after the fsyncing client dies. """ # Leave this guy out until he's needed self.mount_b.umount_wait() # Create dir + child dentry on client A, and fsync the dir path = os.path.join(self.mount_a.mountpoint, "subdir") self.mount_a.run_python( dedent(""" import os import time path = "{0}" print "Starting creation..." start = time.time() os.mkdir(path) f = open(os.path.join(path, "childfile"), "w") f.close() print "Finished creation in {0}s".format(time.time() - start) fd = os.open(path, os.O_DIRECTORY) print "Starting fsync..." start = time.time() os.fsync(fd) print "Finished fsync in {0}s".format(time.time() - start) """.format(path)) ) # Immediately kill the MDS and then client A self.fs.mds_stop() self.fs.mds_fail() self.mount_a.kill() self.mount_a.kill_cleanup() # Restart the MDS. Wait for it to come up, it'll have to time out in clientreplay self.fs.mds_restart() log.info("Waiting for reconnect...") self.fs.wait_for_state("up:reconnect") log.info("Waiting for active...") self.fs.wait_for_state("up:active", timeout=MDS_RESTART_GRACE + self.mds_reconnect_timeout) log.info("Reached active...") # Is the child dentry visible from mount B? self.mount_b.mount() self.mount_b.wait_until_mounted() self.mount_b.run_shell(["ls", "subdir/childfile"])