ceph/qa/tasks/cephfs/test_fragment.py

   1
   2
   3 from tasks.cephfs.cephfs_test_case import CephFSTestCase
   4 from teuthology.orchestra import run
   5
   6 import logging
   7 log = logging.getLogger(__name__)
   8
   9
  10 class TestFragmentation(CephFSTestCase):
  11     CLIENTS_REQUIRED = 1
  12     MDSS_REQUIRED = 1
  13
  14     def get_splits(self):
  15         return self.fs.mds_asok(['perf', 'dump', 'mds'])['mds']['dir_split']
  16
  17     def get_merges(self):
  18         return self.fs.mds_asok(['perf', 'dump', 'mds'])['mds']['dir_merge']
  19
  20     def get_dir_ino(self, path):
  21         dir_cache = self.fs.read_cache(path, 0)
  22         dir_ino = None
  23         dir_inono = self.mount_a.path_to_ino(path.strip("/"))
  24         for ino in dir_cache:
  25             if ino['ino'] == dir_inono:
  26                 dir_ino = ino
  27                 break
  28         self.assertIsNotNone(dir_ino)
  29         return dir_ino
  30
  31     def _configure(self, **kwargs):
  32         """
  33         Apply kwargs as MDS configuration settings, enable dirfrags
  34         and restart the MDSs.
  35         """
  36
  37         for k, v in kwargs.items():
  38             self.ceph_cluster.set_ceph_conf("mds", k, v.__str__())
  39
  40         self.fs.set_allow_dirfrags(True)
  41
  42         self.mds_cluster.mds_fail_restart()
  43         self.fs.wait_for_daemons()
  44
  45     def test_oversize(self):
  46         """
  47         That a directory is split when it becomes too large.
  48         """
  49
  50         split_size = 20
  51         merge_size = 5
  52
  53         self._configure(
  54             mds_bal_split_size=split_size,
  55             mds_bal_merge_size=merge_size,
  56             mds_bal_split_bits=1
  57         )
  58
  59         self.assertEqual(self.get_splits(), 0)
  60
  61         self.mount_a.create_n_files("splitdir/file", split_size + 1)
  62
  63         self.wait_until_true(
  64             lambda: self.get_splits() == 1,
  65             timeout=30
  66         )
  67
  68         frags = self.get_dir_ino("/splitdir")['dirfrags']
  69         self.assertEqual(len(frags), 2)
  70         self.assertEqual(frags[0]['dirfrag'], "0x10000000000.0*")
  71         self.assertEqual(frags[1]['dirfrag'], "0x10000000000.1*")
  72         self.assertEqual(
  73             sum([len(f['dentries']) for f in frags]),
  74             split_size + 1
  75         )
  76
  77         self.assertEqual(self.get_merges(), 0)
  78
  79         self.mount_a.run_shell(["rm", "-f", run.Raw("splitdir/file*")])
  80
  81         self.wait_until_true(
  82             lambda: self.get_merges() == 1,
  83             timeout=30
  84         )
  85
  86         self.assertEqual(len(self.get_dir_ino("/splitdir")["dirfrags"]), 1)
  87
  88     def test_rapid_creation(self):
  89         """
  90         That the fast-splitting limit of 1.5x normal limit is
  91         applied when creating dentries quickly.
  92         """
  93
  94         split_size = 100
  95         merge_size = 1
  96
  97         self._configure(
  98             mds_bal_split_size=split_size,
  99             mds_bal_merge_size=merge_size,
 100             mds_bal_split_bits=3,
 101             mds_bal_fragment_size_max=int(split_size * 1.5 + 2)
 102         )
 103
 104         # We test this only at a single split level.  If a client was sending
 105         # IO so fast that it hit a second split before the first split
 106         # was complete, it could violate mds_bal_fragment_size_max -- there
 107         # is a window where the child dirfrags of a split are unfrozen
 108         # (so they can grow), but still have STATE_FRAGMENTING (so they
 109         # can't be split).
 110
 111         # By writing 4x the split size when the split bits are set
 112         # to 3 (i.e. 4-ways), I am reasonably sure to see precisely
 113         # one split.  The test is to check whether that split
 114         # happens soon enough that the client doesn't exceed
 115         # 2x the split_size (the "immediate" split mode should
 116         # kick in at 1.5x the split size).
 117
 118         self.assertEqual(self.get_splits(), 0)
 119         self.mount_a.create_n_files("splitdir/file", split_size * 4)
 120         self.wait_until_equal(
 121             self.get_splits,
 122             1,
 123             reject_fn=lambda s: s > 1,
 124             timeout=30
 125         )
 126
 127     def test_deep_split(self):
 128         """
 129         That when the directory grows many times larger than split size,
 130         the fragments get split again.
 131         """
 132
 133         split_size = 100
 134         merge_size = 1  # i.e. don't merge frag unless its empty
 135         split_bits = 1
 136
 137         branch_factor = 2**split_bits
 138
 139         # Arbitrary: how many levels shall we try fragmenting before
 140         # ending the test?
 141         max_depth = 5
 142
 143         self._configure(
 144             mds_bal_split_size=split_size,
 145             mds_bal_merge_size=merge_size,
 146             mds_bal_split_bits=split_bits
 147         )
 148
 149         # Each iteration we will create another level of fragments.  The
 150         # placement of dentries into fragments is by hashes (i.e. pseudo
 151         # random), so we rely on statistics to get the behaviour that
 152         # by writing about 1.5x as many dentries as the split_size times
 153         # the number of frags, we will get them all to exceed their
 154         # split size and trigger a split.
 155         depth = 0
 156         files_written = 0
 157         splits_expected = 0
 158         while depth < max_depth:
 159             log.info("Writing files for depth {0}".format(depth))
 160             target_files = branch_factor**depth * int(split_size * 1.5)
 161             create_files = target_files - files_written
 162
 163             self.ceph_cluster.mon_manager.raw_cluster_cmd("log",
 164                 "{0} Writing {1} files (depth={2})".format(
 165                     self.__class__.__name__, create_files, depth
 166                 ))
 167             self.mount_a.create_n_files("splitdir/file_{0}".format(depth),
 168                                         create_files)
 169             self.ceph_cluster.mon_manager.raw_cluster_cmd("log",
 170                 "{0} Done".format(self.__class__.__name__))
 171
 172             files_written += create_files
 173             log.info("Now have {0} files".format(files_written))
 174
 175             splits_expected += branch_factor**depth
 176             log.info("Waiting to see {0} splits".format(splits_expected))
 177             try:
 178                 self.wait_until_equal(
 179                     self.get_splits,
 180                     splits_expected,
 181                     timeout=30,
 182                     reject_fn=lambda x: x > splits_expected
 183                 )
 184
 185                 frags = self.get_dir_ino("/splitdir")['dirfrags']
 186                 self.assertEqual(len(frags), branch_factor**(depth+1))
 187                 self.assertEqual(
 188                     sum([len(f['dentries']) for f in frags]),
 189                     target_files
 190                 )
 191             except:
 192                 # On failures, log what fragmentation we actually ended
 193                 # up with.  This block is just for logging, at the end
 194                 # we raise the exception again.
 195                 frags = self.get_dir_ino("/splitdir")['dirfrags']
 196                 log.info("depth={0} splits_expected={1} files_written={2}".format(
 197                     depth, splits_expected, files_written
 198                 ))
 199                 log.info("Dirfrags:")
 200                 for f in frags:
 201                     log.info("{0}: {1}".format(
 202                         f['dirfrag'], len(f['dentries'])
 203                     ))
 204                 raise
 205
 206             depth += 1
 207
 208         # Remember the inode number because we will be checking for
 209         # objects later.
 210         dir_inode_no = self.mount_a.path_to_ino("splitdir")
 211
 212         self.mount_a.run_shell(["rm", "-rf", "splitdir/"])
 213         self.mount_a.umount_wait()
 214
 215         self.fs.mds_asok(['flush', 'journal'])
 216
 217         # Wait for all strays to purge
 218         self.wait_until_equal(
 219             lambda: self.fs.mds_asok(['perf', 'dump', 'mds_cache']
 220                                      )['mds_cache']['num_strays'],
 221             0,
 222             timeout=1200
 223         )
 224         # Check that the metadata pool objects for all the myriad
 225         # child fragments are gone
 226         metadata_objs = self.fs.rados(["ls"])
 227         frag_objs = []
 228         for o in metadata_objs:
 229             if o.startswith("{0:x}.".format(dir_inode_no)):
 230                 frag_objs.append(o)
 231         self.assertListEqual(frag_objs, [])