ceph/qa/tasks/cephfs/test_client_recovery.py

   1
   2 """
   3 Teuthology task for exercising CephFS client recovery
   4 """
   5
   6 import logging
   7 from textwrap import dedent
   8 import time
   9 import distutils.version as version
  10 import re
  11 import os
  12
  13 from teuthology.orchestra.run import CommandFailedError, ConnectionLostError
  14 from tasks.cephfs.fuse_mount import FuseMount
  15 from tasks.cephfs.cephfs_test_case import CephFSTestCase
  16 from teuthology.packaging import get_package_version
  17 from unittest import SkipTest
  18
  19
  20 log = logging.getLogger(__name__)
  21
  22
  23 # Arbitrary timeouts for operations involving restarting
  24 # an MDS or waiting for it to come up
  25 MDS_RESTART_GRACE = 60
  26
  27
  28 class TestClientNetworkRecovery(CephFSTestCase):
  29     REQUIRE_KCLIENT_REMOTE = True
  30     REQUIRE_ONE_CLIENT_REMOTE = True
  31     CLIENTS_REQUIRED = 2
  32
  33     LOAD_SETTINGS = ["mds_reconnect_timeout", "ms_max_backoff"]
  34
  35     # Environment references
  36     mds_reconnect_timeout = None
  37     ms_max_backoff = None
  38
  39     def test_network_death(self):
  40         """
  41         Simulate software freeze or temporary network failure.
  42
  43         Check that the client blocks I/O during failure, and completes
  44         I/O after failure.
  45         """
  46
  47         session_timeout = self.fs.get_var("session_timeout")
  48         self.fs.mds_asok(['config', 'set', 'mds_defer_session_stale', 'false'])
  49
  50         # We only need one client
  51         self.mount_b.umount_wait()
  52
  53         # Initially our one client session should be visible
  54         client_id = self.mount_a.get_global_id()
  55         ls_data = self._session_list()
  56         self.assert_session_count(1, ls_data)
  57         self.assertEqual(ls_data[0]['id'], client_id)
  58         self.assert_session_state(client_id, "open")
  59
  60         # ...and capable of doing I/O without blocking
  61         self.mount_a.create_files()
  62
  63         # ...but if we turn off the network
  64         self.fs.set_clients_block(True)
  65
  66         # ...and try and start an I/O
  67         write_blocked = self.mount_a.write_background()
  68
  69         # ...then it should block
  70         self.assertFalse(write_blocked.finished)
  71         self.assert_session_state(client_id, "open")
  72         time.sleep(session_timeout * 1.5)  # Long enough for MDS to consider session stale
  73         self.assertFalse(write_blocked.finished)
  74         self.assert_session_state(client_id, "stale")
  75
  76         # ...until we re-enable I/O
  77         self.fs.set_clients_block(False)
  78
  79         # ...when it should complete promptly
  80         a = time.time()
  81         self.wait_until_true(lambda: write_blocked.finished, self.ms_max_backoff * 2)
  82         write_blocked.wait()  # Already know we're finished, wait() to raise exception on errors
  83         recovery_time = time.time() - a
  84         log.info("recovery time: {0}".format(recovery_time))
  85         self.assert_session_state(client_id, "open")
  86
  87
  88 class TestClientRecovery(CephFSTestCase):
  89     REQUIRE_KCLIENT_REMOTE = True
  90     CLIENTS_REQUIRED = 2
  91
  92     LOAD_SETTINGS = ["mds_reconnect_timeout", "ms_max_backoff"]
  93
  94     # Environment references
  95     mds_reconnect_timeout = None
  96     ms_max_backoff = None
  97
  98     def test_basic(self):
  99         # Check that two clients come up healthy and see each others' files
 100         # =====================================================
 101         self.mount_a.create_files()
 102         self.mount_a.check_files()
 103         self.mount_a.umount_wait()
 104
 105         self.mount_b.check_files()
 106
 107         self.mount_a.mount()
 108         self.mount_a.wait_until_mounted()
 109
 110         # Check that the admin socket interface is correctly reporting
 111         # two sessions
 112         # =====================================================
 113         ls_data = self._session_list()
 114         self.assert_session_count(2, ls_data)
 115
 116         self.assertSetEqual(
 117             set([l['id'] for l in ls_data]),
 118             {self.mount_a.get_global_id(), self.mount_b.get_global_id()}
 119         )
 120
 121     def test_restart(self):
 122         # Check that after an MDS restart both clients reconnect and continue
 123         # to handle I/O
 124         # =====================================================
 125         self.fs.mds_fail_restart()
 126         self.fs.wait_for_state('up:active', timeout=MDS_RESTART_GRACE)
 127
 128         self.mount_a.create_destroy()
 129         self.mount_b.create_destroy()
 130
 131     def _session_num_caps(self, client_id):
 132         ls_data = self.fs.mds_asok(['session', 'ls'])
 133         return int(self._session_by_id(ls_data).get(client_id, {'num_caps': None})['num_caps'])
 134
 135     def test_reconnect_timeout(self):
 136         # Reconnect timeout
 137         # =================
 138         # Check that if I stop an MDS and a client goes away, the MDS waits
 139         # for the reconnect period
 140         self.fs.mds_stop()
 141         self.fs.mds_fail()
 142
 143         mount_a_client_id = self.mount_a.get_global_id()
 144         self.mount_a.umount_wait(force=True)
 145
 146         self.fs.mds_restart()
 147
 148         self.fs.wait_for_state('up:reconnect', reject='up:active', timeout=MDS_RESTART_GRACE)
 149         # Check that the MDS locally reports its state correctly
 150         status = self.fs.mds_asok(['status'])
 151         self.assertIn("reconnect_status", status)
 152
 153         ls_data = self._session_list()
 154         self.assert_session_count(2, ls_data)
 155
 156         # The session for the dead client should have the 'reconnect' flag set
 157         self.assertTrue(self.get_session(mount_a_client_id)['reconnecting'])
 158
 159         # Wait for the reconnect state to clear, this should take the
 160         # reconnect timeout period.
 161         in_reconnect_for = self.fs.wait_for_state('up:active', timeout=self.mds_reconnect_timeout * 2)
 162         # Check that the period we waited to enter active is within a factor
 163         # of two of the reconnect timeout.
 164         self.assertGreater(in_reconnect_for, self.mds_reconnect_timeout / 2,
 165                            "Should have been in reconnect phase for {0} but only took {1}".format(
 166                                self.mds_reconnect_timeout, in_reconnect_for
 167                            ))
 168
 169         self.assert_session_count(1)
 170
 171         # Check that the client that timed out during reconnect can
 172         # mount again and do I/O
 173         self.mount_a.mount()
 174         self.mount_a.wait_until_mounted()
 175         self.mount_a.create_destroy()
 176
 177         self.assert_session_count(2)
 178
 179     def test_reconnect_eviction(self):
 180         # Eviction during reconnect
 181         # =========================
 182         mount_a_client_id = self.mount_a.get_global_id()
 183
 184         self.fs.mds_stop()
 185         self.fs.mds_fail()
 186
 187         # The mount goes away while the MDS is offline
 188         self.mount_a.kill()
 189
 190         self.fs.mds_restart()
 191
 192         # Enter reconnect phase
 193         self.fs.wait_for_state('up:reconnect', reject='up:active', timeout=MDS_RESTART_GRACE)
 194         self.assert_session_count(2)
 195
 196         # Evict the stuck client
 197         self.fs.mds_asok(['session', 'evict', "%s" % mount_a_client_id])
 198         self.assert_session_count(1)
 199
 200         # Observe that we proceed to active phase without waiting full reconnect timeout
 201         evict_til_active = self.fs.wait_for_state('up:active', timeout=MDS_RESTART_GRACE)
 202         # Once we evict the troublemaker, the reconnect phase should complete
 203         # in well under the reconnect timeout.
 204         self.assertLess(evict_til_active, self.mds_reconnect_timeout * 0.5,
 205                         "reconnect did not complete soon enough after eviction, took {0}".format(
 206                             evict_til_active
 207                         ))
 208
 209         # We killed earlier so must clean up before trying to use again
 210         self.mount_a.kill_cleanup()
 211
 212         # Bring the client back
 213         self.mount_a.mount()
 214         self.mount_a.wait_until_mounted()
 215         self.mount_a.create_destroy()
 216
 217     def _test_stale_caps(self, write):
 218         session_timeout = self.fs.get_var("session_timeout")
 219
 220         # Capability release from stale session
 221         # =====================================
 222         if write:
 223             cap_holder = self.mount_a.open_background()
 224         else:
 225             self.mount_a.run_shell(["touch", "background_file"])
 226             self.mount_a.umount_wait()
 227             self.mount_a.mount()
 228             self.mount_a.wait_until_mounted()
 229             cap_holder = self.mount_a.open_background(write=False)
 230
 231         self.assert_session_count(2)
 232         mount_a_gid = self.mount_a.get_global_id()
 233
 234         # Wait for the file to be visible from another client, indicating
 235         # that mount_a has completed its network ops
 236         self.mount_b.wait_for_visible()
 237
 238         # Simulate client death
 239         self.mount_a.kill()
 240
 241         # wait for it to die so it doesn't voluntarily release buffer cap
 242         time.sleep(5)
 243
 244         try:
 245             # Now, after session_timeout seconds, the waiter should
 246             # complete their operation when the MDS marks the holder's
 247             # session stale.
 248             cap_waiter = self.mount_b.write_background()
 249             a = time.time()
 250             cap_waiter.wait()
 251             b = time.time()
 252
 253             # Should have succeeded
 254             self.assertEqual(cap_waiter.exitstatus, 0)
 255
 256             if write:
 257                 self.assert_session_count(1)
 258             else:
 259                 self.assert_session_state(mount_a_gid, "stale")
 260
 261             cap_waited = b - a
 262             log.info("cap_waiter waited {0}s".format(cap_waited))
 263             self.assertTrue(session_timeout / 2.0 <= cap_waited <= session_timeout * 2.0,
 264                             "Capability handover took {0}, expected approx {1}".format(
 265                                 cap_waited, session_timeout
 266                             ))
 267
 268             cap_holder.stdin.close()
 269             try:
 270                 cap_holder.wait()
 271             except (CommandFailedError, ConnectionLostError):
 272                 # We killed it (and possibly its node), so it raises an error
 273                 pass
 274         finally:
 275             # teardown() doesn't quite handle this case cleanly, so help it out
 276             self.mount_a.kill_cleanup()
 277
 278         self.mount_a.mount()
 279         self.mount_a.wait_until_mounted()
 280
 281     def test_stale_read_caps(self):
 282         self._test_stale_caps(False)
 283
 284     def test_stale_write_caps(self):
 285         self._test_stale_caps(True)
 286
 287     def test_evicted_caps(self):
 288         # Eviction while holding a capability
 289         # ===================================
 290
 291         session_timeout = self.fs.get_var("session_timeout")
 292
 293         # Take out a write capability on a file on client A,
 294         # and then immediately kill it.
 295         cap_holder = self.mount_a.open_background()
 296         mount_a_client_id = self.mount_a.get_global_id()
 297
 298         # Wait for the file to be visible from another client, indicating
 299         # that mount_a has completed its network ops
 300         self.mount_b.wait_for_visible()
 301
 302         # Simulate client death
 303         self.mount_a.kill()
 304
 305         # wait for it to die so it doesn't voluntarily release buffer cap
 306         time.sleep(5)
 307
 308         try:
 309             # The waiter should get stuck waiting for the capability
 310             # held on the MDS by the now-dead client A
 311             cap_waiter = self.mount_b.write_background()
 312             time.sleep(5)
 313             self.assertFalse(cap_waiter.finished)
 314
 315             self.fs.mds_asok(['session', 'evict', "%s" % mount_a_client_id])
 316             # Now, because I evicted the old holder of the capability, it should
 317             # immediately get handed over to the waiter
 318             a = time.time()
 319             cap_waiter.wait()
 320             b = time.time()
 321             cap_waited = b - a
 322             log.info("cap_waiter waited {0}s".format(cap_waited))
 323             # This is the check that it happened 'now' rather than waiting
 324             # for the session timeout
 325             self.assertLess(cap_waited, session_timeout / 2.0,
 326                             "Capability handover took {0}, expected less than {1}".format(
 327                                 cap_waited, session_timeout / 2.0
 328                             ))
 329
 330             cap_holder.stdin.close()
 331             try:
 332                 cap_holder.wait()
 333             except (CommandFailedError, ConnectionLostError):
 334                 # We killed it (and possibly its node), so it raises an error
 335                 pass
 336         finally:
 337             self.mount_a.kill_cleanup()
 338
 339         self.mount_a.mount()
 340         self.mount_a.wait_until_mounted()
 341
 342     def test_trim_caps(self):
 343         # Trim capability when reconnecting MDS
 344         # ===================================
 345
 346         count = 500
 347         # Create lots of files
 348         for i in range(count):
 349             self.mount_a.run_shell(["touch", "f{0}".format(i)])
 350
 351         # Populate mount_b's cache
 352         self.mount_b.run_shell(["ls", "-l"])
 353
 354         client_id = self.mount_b.get_global_id()
 355         num_caps = self._session_num_caps(client_id)
 356         self.assertGreaterEqual(num_caps, count)
 357
 358         # Restart MDS. client should trim its cache when reconnecting to the MDS
 359         self.fs.mds_fail_restart()
 360         self.fs.wait_for_state('up:active', timeout=MDS_RESTART_GRACE)
 361
 362         num_caps = self._session_num_caps(client_id)
 363         self.assertLess(num_caps, count,
 364                         "should have less than {0} capabilities, have {1}".format(
 365                             count, num_caps
 366                         ))
 367
 368     def _is_flockable(self):
 369         a_version_str = get_package_version(self.mount_a.client_remote, "fuse")
 370         b_version_str = get_package_version(self.mount_b.client_remote, "fuse")
 371         flock_version_str = "2.9"
 372
 373         version_regex = re.compile(r"[0-9\.]+")
 374         a_result = version_regex.match(a_version_str)
 375         self.assertTrue(a_result)
 376         b_result = version_regex.match(b_version_str)
 377         self.assertTrue(b_result)
 378         a_version = version.StrictVersion(a_result.group())
 379         b_version = version.StrictVersion(b_result.group())
 380         flock_version=version.StrictVersion(flock_version_str)
 381
 382         if (a_version >= flock_version and b_version >= flock_version):
 383             log.info("flock locks are available")
 384             return True
 385         else:
 386             log.info("not testing flock locks, machines have versions {av} and {bv}".format(
 387                 av=a_version_str,bv=b_version_str))
 388             return False
 389
 390     def test_filelock(self):
 391         """
 392         Check that file lock doesn't get lost after an MDS restart
 393         """
 394
 395         flockable = self._is_flockable()
 396         lock_holder = self.mount_a.lock_background(do_flock=flockable)
 397
 398         self.mount_b.wait_for_visible("background_file-2")
 399         self.mount_b.check_filelock(do_flock=flockable)
 400
 401         self.fs.mds_fail_restart()
 402         self.fs.wait_for_state('up:active', timeout=MDS_RESTART_GRACE)
 403
 404         self.mount_b.check_filelock(do_flock=flockable)
 405
 406         # Tear down the background process
 407         lock_holder.stdin.close()
 408         try:
 409             lock_holder.wait()
 410         except (CommandFailedError, ConnectionLostError):
 411             # We killed it, so it raises an error
 412             pass
 413
 414     def test_filelock_eviction(self):
 415         """
 416         Check that file lock held by evicted client is given to
 417         waiting client.
 418         """
 419         if not self._is_flockable():
 420             self.skipTest("flock is not available")
 421
 422         lock_holder = self.mount_a.lock_background()
 423         self.mount_b.wait_for_visible("background_file-2")
 424         self.mount_b.check_filelock()
 425
 426         lock_taker = self.mount_b.lock_and_release()
 427         # Check the taker is waiting (doesn't get it immediately)
 428         time.sleep(2)
 429         self.assertFalse(lock_holder.finished)
 430         self.assertFalse(lock_taker.finished)
 431
 432         try:
 433             mount_a_client_id = self.mount_a.get_global_id()
 434             self.fs.mds_asok(['session', 'evict', "%s" % mount_a_client_id])
 435
 436             # Evicting mount_a should let mount_b's attempt to take the lock
 437             # succeed
 438             self.wait_until_true(lambda: lock_taker.finished, timeout=10)
 439         finally:
 440             # teardown() doesn't quite handle this case cleanly, so help it out
 441             self.mount_a.kill()
 442             self.mount_a.kill_cleanup()
 443
 444         # Bring the client back
 445         self.mount_a.mount()
 446         self.mount_a.wait_until_mounted()
 447
 448     def test_dir_fsync(self):
 449         self._test_fsync(True);
 450
 451     def test_create_fsync(self):
 452         self._test_fsync(False);
 453
 454     def _test_fsync(self, dirfsync):
 455         """
 456         That calls to fsync guarantee visibility of metadata to another
 457         client immediately after the fsyncing client dies.
 458         """
 459
 460         # Leave this guy out until he's needed
 461         self.mount_b.umount_wait()
 462
 463         # Create dir + child dentry on client A, and fsync the dir
 464         path = os.path.join(self.mount_a.mountpoint, "subdir")
 465         self.mount_a.run_python(
 466             dedent("""
 467                 import os
 468                 import time
 469
 470                 path = "{path}"
 471
 472                 print "Starting creation..."
 473                 start = time.time()
 474
 475                 os.mkdir(path)
 476                 dfd = os.open(path, os.O_DIRECTORY)
 477
 478                 fd = open(os.path.join(path, "childfile"), "w")
 479                 print "Finished creation in {{0}}s".format(time.time() - start)
 480
 481                 print "Starting fsync..."
 482                 start = time.time()
 483                 if {dirfsync}:
 484                     os.fsync(dfd)
 485                 else:
 486                     os.fsync(fd)
 487                 print "Finished fsync in {{0}}s".format(time.time() - start)
 488             """.format(path=path,dirfsync=str(dirfsync)))
 489         )
 490
 491         # Immediately kill the MDS and then client A
 492         self.fs.mds_stop()
 493         self.fs.mds_fail()
 494         self.mount_a.kill()
 495         self.mount_a.kill_cleanup()
 496
 497         # Restart the MDS.  Wait for it to come up, it'll have to time out in clientreplay
 498         self.fs.mds_restart()
 499         log.info("Waiting for reconnect...")
 500         self.fs.wait_for_state("up:reconnect")
 501         log.info("Waiting for active...")
 502         self.fs.wait_for_state("up:active", timeout=MDS_RESTART_GRACE + self.mds_reconnect_timeout)
 503         log.info("Reached active...")
 504
 505         # Is the child dentry visible from mount B?
 506         self.mount_b.mount()
 507         self.mount_b.wait_until_mounted()
 508         self.mount_b.run_shell(["ls", "subdir/childfile"])
 509
 510     def test_unmount_for_evicted_client(self):
 511         """Test if client hangs on unmount after evicting the client."""
 512         mount_a_client_id = self.mount_a.get_global_id()
 513         self.fs.mds_asok(['session', 'evict', "%s" % mount_a_client_id])
 514
 515         self.mount_a.umount_wait(require_clean=True, timeout=30)
 516
 517     def test_stale_renew(self):
 518         if not isinstance(self.mount_a, FuseMount):
 519             raise SkipTest("Require FUSE client to handle signal STOP/CONT")
 520
 521         session_timeout = self.fs.get_var("session_timeout")
 522
 523         self.mount_a.run_shell(["mkdir", "testdir"])
 524         self.mount_a.run_shell(["touch", "testdir/file1"])
 525         # populate readdir cache
 526         self.mount_a.run_shell(["ls", "testdir"])
 527         self.mount_b.run_shell(["ls", "testdir"])
 528
 529         # check if readdir cache is effective
 530         initial_readdirs = self.fs.mds_asok(['perf', 'dump', 'mds_server', 'req_readdir_latency'])
 531         self.mount_b.run_shell(["ls", "testdir"])
 532         current_readdirs = self.fs.mds_asok(['perf', 'dump', 'mds_server', 'req_readdir_latency'])
 533         self.assertEqual(current_readdirs, initial_readdirs);
 534
 535         mount_b_gid = self.mount_b.get_global_id()
 536         mount_b_pid = self.mount_b.get_client_pid()
 537         # stop ceph-fuse process of mount_b
 538         self.mount_b.client_remote.run(args=["sudo", "kill", "-STOP", mount_b_pid])
 539
 540         self.assert_session_state(mount_b_gid, "open")
 541         time.sleep(session_timeout * 1.5)  # Long enough for MDS to consider session stale
 542
 543         self.mount_a.run_shell(["touch", "testdir/file2"])
 544         self.assert_session_state(mount_b_gid, "stale")
 545
 546         # resume ceph-fuse process of mount_b
 547         self.mount_b.client_remote.run(args=["sudo", "kill", "-CONT", mount_b_pid])
 548         # Is the new file visible from mount_b? (caps become invalid after session stale)
 549         self.mount_b.run_shell(["ls", "testdir/file2"])
 550
 551     def test_abort_conn(self):
 552         """
 553         Check that abort_conn() skips closing mds sessions.
 554         """
 555         if not isinstance(self.mount_a, FuseMount):
 556             raise SkipTest("Testing libcephfs function")
 557
 558         self.fs.mds_asok(['config', 'set', 'mds_defer_session_stale', 'false'])
 559         session_timeout = self.fs.get_var("session_timeout")
 560
 561         self.mount_a.umount_wait()
 562         self.mount_b.umount_wait()
 563
 564         gid_str = self.mount_a.run_python(dedent("""
 565             import cephfs as libcephfs
 566             cephfs = libcephfs.LibCephFS(conffile='')
 567             cephfs.mount()
 568             client_id = cephfs.get_instance_id()
 569             cephfs.abort_conn()
 570             print client_id
 571             """)
 572         )
 573         gid = int(gid_str);
 574
 575         self.assert_session_state(gid, "open")
 576         time.sleep(session_timeout * 1.5)  # Long enough for MDS to consider session stale
 577         self.assert_session_state(gid, "stale")
 578
 579     def test_dont_mark_unresponsive_client_stale(self):
 580         """
 581         Test that an unresponsive client holding caps is not marked stale or
 582         evicted unless another clients wants its caps.
 583         """
 584         if not isinstance(self.mount_a, FuseMount):
 585             self.skipTest("Require FUSE client to handle signal STOP/CONT")
 586
 587         # XXX: To conduct this test we need at least two clients since a
 588         # single client is never evcited by MDS.
 589         SESSION_TIMEOUT = 30
 590         SESSION_AUTOCLOSE = 50
 591         time_at_beg = time.time()
 592         mount_a_gid = self.mount_a.get_global_id()
 593         mount_a_pid = self.mount_a.client_pid
 594         self.fs.set_var('session_timeout', SESSION_TIMEOUT)
 595         self.fs.set_var('session_autoclose', SESSION_AUTOCLOSE)
 596         self.assert_session_count(2, self.fs.mds_asok(['session', 'ls']))
 597
 598         # test that client holding cap not required by any other client is not
 599         # marked stale when it becomes unresponsive.
 600         self.mount_a.run_shell(['mkdir', 'dir'])
 601         self.mount_a.send_signal('sigstop')
 602         time.sleep(SESSION_TIMEOUT + 2)
 603         self.assert_session_state(mount_a_gid, "open")
 604
 605         # test that other clients have to wait to get the caps from
 606         # unresponsive client until session_autoclose.
 607         self.mount_b.run_shell(['stat', 'dir'])
 608         self.assert_session_count(1, self.fs.mds_asok(['session', 'ls']))
 609         self.assertLess(time.time(), time_at_beg + SESSION_AUTOCLOSE)
 610
 611         self.mount_a.send_signal('sigcont')