tests/qemu-iotests/093

   1 #!/usr/bin/env python3
   2 # group: throttle
   3 #
   4 # Tests for IO throttling
   5 #
   6 # Copyright (C) 2015 Red Hat, Inc.
   7 # Copyright (C) 2015-2016 Igalia, S.L.
   8 #
   9 # This program is free software; you can redistribute it and/or modify
  10 # it under the terms of the GNU General Public License as published by
  11 # the Free Software Foundation; either version 2 of the License, or
  12 # (at your option) any later version.
  13 #
  14 # This program is distributed in the hope that it will be useful,
  15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 # GNU General Public License for more details.
  18 #
  19 # You should have received a copy of the GNU General Public License
  20 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 #
  22
  23 import iotests
  24
  25 nsec_per_sec = 1000000000
  26
  27 class ThrottleTestCase(iotests.QMPTestCase):
  28     test_driver = "null-aio"
  29     max_drives = 3
  30
  31     def blockstats(self, device):
  32         result = self.vm.qmp("query-blockstats")
  33         for r in result['return']:
  34             if r['device'] == device:
  35                 stat = r['stats']
  36                 return stat['rd_bytes'], stat['rd_operations'], stat['wr_bytes'], stat['wr_operations']
  37         raise Exception("Device not found for blockstats: %s" % device)
  38
  39     def required_drivers(self):
  40         return [self.test_driver]
  41
  42     @iotests.skip_if_unsupported(required_drivers)
  43     def setUp(self):
  44         self.vm = iotests.VM()
  45         for i in range(0, self.max_drives):
  46             self.vm.add_drive(self.test_driver + "://", "file.read-zeroes=on")
  47         self.vm.launch()
  48
  49     def tearDown(self):
  50         self.vm.shutdown()
  51
  52     def configure_throttle(self, ndrives, params):
  53         params['group'] = 'test'
  54
  55         # Set the I/O throttling parameters to all drives
  56         for i in range(0, ndrives):
  57             params['device'] = 'drive%d' % i
  58             self.vm.cmd("block_set_io_throttle", conv_keys=False, **params)
  59
  60     def do_test_throttle(self, ndrives, seconds, params, first_drive = 0):
  61         def check_limit(limit, num):
  62             # IO throttling algorithm is discrete, allow 10% error so the test
  63             # is more robust
  64             return limit == 0 or \
  65                    (num < seconds * limit * 1.1 / ndrives
  66                    and num > seconds * limit * 0.9 / ndrives)
  67
  68         # Set vm clock to a known value
  69         ns = seconds * nsec_per_sec
  70         self.vm.qtest("clock_step %d" % ns)
  71
  72         # Submit enough requests so the throttling mechanism kicks
  73         # in. The throttled requests won't be executed until we
  74         # advance the virtual clock.
  75         rq_size = 512
  76         rd_nr = max(params['bps'] // rq_size // 2,
  77                     params['bps_rd'] // rq_size,
  78                     params['iops'] // 2,
  79                     params['iops_rd'])
  80         rd_nr *= seconds * 2
  81         rd_nr //= ndrives
  82         wr_nr = max(params['bps'] // rq_size // 2,
  83                     params['bps_wr'] // rq_size,
  84                     params['iops'] // 2,
  85                     params['iops_wr'])
  86         wr_nr *= seconds * 2
  87         wr_nr //= ndrives
  88
  89         # Send I/O requests to all drives
  90         for i in range(rd_nr):
  91             for drive in range(0, ndrives):
  92                 idx = first_drive + drive
  93                 self.vm.hmp_qemu_io("drive%d" % idx, "aio_read %d %d" %
  94                                     (i * rq_size, rq_size))
  95
  96         for i in range(wr_nr):
  97             for drive in range(0, ndrives):
  98                 idx = first_drive + drive
  99                 self.vm.hmp_qemu_io("drive%d" % idx, "aio_write %d %d" %
 100                                     (i * rq_size, rq_size))
 101
 102         # We'll store the I/O stats for each drive in these arrays
 103         start_rd_bytes = [0] * ndrives
 104         start_rd_iops  = [0] * ndrives
 105         start_wr_bytes = [0] * ndrives
 106         start_wr_iops  = [0] * ndrives
 107         end_rd_bytes   = [0] * ndrives
 108         end_rd_iops    = [0] * ndrives
 109         end_wr_bytes   = [0] * ndrives
 110         end_wr_iops    = [0] * ndrives
 111
 112         # Read the stats before advancing the clock
 113         for i in range(0, ndrives):
 114             idx = first_drive + i
 115             start_rd_bytes[i], start_rd_iops[i], start_wr_bytes[i], \
 116                 start_wr_iops[i] = self.blockstats('drive%d' % idx)
 117
 118         self.vm.qtest("clock_step %d" % ns)
 119
 120         # Read the stats after advancing the clock
 121         for i in range(0, ndrives):
 122             idx = first_drive + i
 123             end_rd_bytes[i], end_rd_iops[i], end_wr_bytes[i], \
 124                 end_wr_iops[i] = self.blockstats('drive%d' % idx)
 125
 126         # Check that the I/O is within the limits and evenly distributed
 127         for i in range(0, ndrives):
 128             rd_bytes = end_rd_bytes[i] - start_rd_bytes[i]
 129             rd_iops = end_rd_iops[i] - start_rd_iops[i]
 130             wr_bytes = end_wr_bytes[i] - start_wr_bytes[i]
 131             wr_iops = end_wr_iops[i] - start_wr_iops[i]
 132
 133             self.assertTrue(check_limit(params['bps'], rd_bytes + wr_bytes))
 134             self.assertTrue(check_limit(params['bps_rd'], rd_bytes))
 135             self.assertTrue(check_limit(params['bps_wr'], wr_bytes))
 136             self.assertTrue(check_limit(params['iops'], rd_iops + wr_iops))
 137             self.assertTrue(check_limit(params['iops_rd'], rd_iops))
 138             self.assertTrue(check_limit(params['iops_wr'], wr_iops))
 139
 140         # Allow remaining requests to finish.  We submitted twice as many to
 141         # ensure the throttle limit is reached.
 142         self.vm.qtest("clock_step %d" % ns)
 143
 144     # Connect N drives to a VM and test I/O in all of them
 145     def test_all(self):
 146         params = {"bps": 4096,
 147                   "bps_rd": 4096,
 148                   "bps_wr": 4096,
 149                   "iops": 10,
 150                   "iops_rd": 10,
 151                   "iops_wr": 10,
 152                  }
 153         # Repeat the test with different numbers of drives
 154         for ndrives in range(1, self.max_drives + 1):
 155             # Pick each out of all possible params and test
 156             for tk in params:
 157                 limits = dict([(k, 0) for k in params])
 158                 limits[tk] = params[tk] * ndrives
 159                 self.configure_throttle(ndrives, limits)
 160                 self.do_test_throttle(ndrives, 5, limits)
 161
 162     # Connect N drives to a VM and test I/O in just one of them a time
 163     def test_one(self):
 164         params = {"bps": 4096,
 165                   "bps_rd": 4096,
 166                   "bps_wr": 4096,
 167                   "iops": 10,
 168                   "iops_rd": 10,
 169                   "iops_wr": 10,
 170                  }
 171         # Repeat the test for each one of the drives
 172         for drive in range(0, self.max_drives):
 173             # Pick each out of all possible params and test
 174             for tk in params:
 175                 limits = dict([(k, 0) for k in params])
 176                 limits[tk] = params[tk] * self.max_drives
 177                 self.configure_throttle(self.max_drives, limits)
 178                 self.do_test_throttle(1, 5, limits, drive)
 179
 180     def test_burst(self):
 181         params = {"bps": 4096,
 182                   "bps_rd": 4096,
 183                   "bps_wr": 4096,
 184                   "iops": 10,
 185                   "iops_rd": 10,
 186                   "iops_wr": 10,
 187                  }
 188         ndrives = 1
 189         # Pick each out of all possible params and test
 190         for tk in params:
 191             rate = params[tk] * ndrives
 192             burst_rate = rate * 7
 193             burst_length = 4
 194
 195             # Configure the throttling settings
 196             settings = dict([(k, 0) for k in params])
 197             settings[tk] = rate
 198             settings['%s_max' % tk] = burst_rate
 199             settings['%s_max_length' % tk] = burst_length
 200             self.configure_throttle(ndrives, settings)
 201
 202             # Wait for the bucket to empty so we can do bursts
 203             wait_ns = nsec_per_sec * burst_length * burst_rate // rate
 204             self.vm.qtest("clock_step %d" % wait_ns)
 205
 206             # Test I/O at the max burst rate
 207             limits = dict([(k, 0) for k in params])
 208             limits[tk] = burst_rate
 209             self.do_test_throttle(ndrives, burst_length, limits)
 210
 211             # Now test I/O at the normal rate
 212             limits[tk] = rate
 213             self.do_test_throttle(ndrives, 5, limits)
 214
 215     # Test that removing a drive from a throttle group should not
 216     # affect the remaining members of the group.
 217     # https://bugzilla.redhat.com/show_bug.cgi?id=1535914
 218     def test_remove_group_member(self):
 219         # Create a throttle group with two drives
 220         # and set a 4 KB/s read limit.
 221         params = {"bps": 0,
 222                   "bps_rd": 4096,
 223                   "bps_wr": 0,
 224                   "iops": 0,
 225                   "iops_rd": 0,
 226                   "iops_wr": 0 }
 227         self.configure_throttle(2, params)
 228
 229         # Read 4KB from drive0. This is performed immediately.
 230         self.vm.hmp_qemu_io("drive0", "aio_read 0 4096")
 231
 232         # Read 2KB. The I/O limit has been exceeded so this
 233         # request is throttled and a timer is set to wake it up.
 234         self.vm.hmp_qemu_io("drive0", "aio_read 0 2048")
 235
 236         # Read 2KB again. We're still over the I/O limit so this is
 237         # request is also throttled, but no new timer is set since
 238         # there's already one.
 239         self.vm.hmp_qemu_io("drive0", "aio_read 0 2048")
 240
 241         # Read from drive1. This request is also throttled, and no
 242         # timer is set in drive1 because there's already one in
 243         # drive0.
 244         self.vm.hmp_qemu_io("drive1", "aio_read 0 4096")
 245
 246         # At this point only the first 4KB have been read from drive0.
 247         # The other requests are throttled.
 248         self.assertEqual(self.blockstats('drive0')[0], 4096)
 249         self.assertEqual(self.blockstats('drive1')[0], 0)
 250
 251         # Remove drive0 from the throttle group and disable its I/O limits.
 252         # drive1 remains in the group with a throttled request.
 253         params['bps_rd'] = 0
 254         params['device'] = 'drive0'
 255         self.vm.cmd("block_set_io_throttle", conv_keys=False, **params)
 256
 257         # Removing the I/O limits from drive0 drains its two pending requests.
 258         # The read request in drive1 is still throttled.
 259         self.assertEqual(self.blockstats('drive0')[0], 8192)
 260         self.assertEqual(self.blockstats('drive1')[0], 0)
 261
 262         # Advance the clock 5 seconds. This completes the request in drive1
 263         self.vm.qtest("clock_step %d" % (5 * nsec_per_sec))
 264
 265         # Now all requests have been processed.
 266         self.assertEqual(self.blockstats('drive0')[0], 8192)
 267         self.assertEqual(self.blockstats('drive1')[0], 4096)
 268
 269 class ThrottleTestCoroutine(ThrottleTestCase):
 270     test_driver = "null-co"
 271
 272 class ThrottleTestGroupNames(iotests.QMPTestCase):
 273     max_drives = 3
 274
 275     def setUp(self):
 276         self.vm = iotests.VM()
 277         for i in range(0, self.max_drives):
 278             self.vm.add_drive("null-co://",
 279                               "throttling.iops-total=100,file.read-zeroes=on")
 280         self.vm.launch()
 281
 282     def tearDown(self):
 283         self.vm.shutdown()
 284
 285     def set_io_throttle(self, device, params):
 286         params["device"] = device
 287         self.vm.cmd("block_set_io_throttle", conv_keys=False, **params)
 288
 289     def verify_name(self, device, name):
 290         result = self.vm.qmp("query-block")
 291         for r in result["return"]:
 292             if r["device"] == device:
 293                 info = r["inserted"]
 294                 if name:
 295                     self.assertEqual(info["group"], name)
 296                 else:
 297                     self.assertFalse('group' in info)
 298                 return
 299
 300         raise Exception("No group information found for '%s'" % device)
 301
 302     def test_group_naming(self):
 303         params = {"bps": 0,
 304                   "bps_rd": 0,
 305                   "bps_wr": 0,
 306                   "iops": 0,
 307                   "iops_rd": 0,
 308                   "iops_wr": 0}
 309
 310         # Check the drives added using the command line.
 311         # The default throttling group name is the device name.
 312         for i in range(self.max_drives):
 313             devname = "drive%d" % i
 314             self.verify_name(devname, devname)
 315
 316         # Clear throttling settings => the group name is gone.
 317         for i in range(self.max_drives):
 318             devname = "drive%d" % i
 319             self.set_io_throttle(devname, params)
 320             self.verify_name(devname, None)
 321
 322         # Set throttling settings using block_set_io_throttle and
 323         # check the default group names.
 324         params["iops"] = 10
 325         for i in range(self.max_drives):
 326             devname = "drive%d" % i
 327             self.set_io_throttle(devname, params)
 328             self.verify_name(devname, devname)
 329
 330         # Set a custom group name for each device
 331         for i in range(3):
 332             devname = "drive%d" % i
 333             groupname = "group%d" % i
 334             params['group'] = groupname
 335             self.set_io_throttle(devname, params)
 336             self.verify_name(devname, groupname)
 337
 338         # Put drive0 in group1 and check that all other devices remain
 339         # unchanged
 340         params['group'] = 'group1'
 341         self.set_io_throttle('drive0', params)
 342         self.verify_name('drive0', 'group1')
 343         for i in range(1, self.max_drives):
 344             devname = "drive%d" % i
 345             groupname = "group%d" % i
 346             self.verify_name(devname, groupname)
 347
 348         # Put drive0 in group2 and check that all other devices remain
 349         # unchanged
 350         params['group'] = 'group2'
 351         self.set_io_throttle('drive0', params)
 352         self.verify_name('drive0', 'group2')
 353         for i in range(1, self.max_drives):
 354             devname = "drive%d" % i
 355             groupname = "group%d" % i
 356             self.verify_name(devname, groupname)
 357
 358         # Clear throttling settings from drive0 check that all other
 359         # devices remain unchanged
 360         params["iops"] = 0
 361         self.set_io_throttle('drive0', params)
 362         self.verify_name('drive0', None)
 363         for i in range(1, self.max_drives):
 364             devname = "drive%d" % i
 365             groupname = "group%d" % i
 366             self.verify_name(devname, groupname)
 367
 368 class ThrottleTestRemovableMedia(iotests.QMPTestCase):
 369     def setUp(self):
 370         self.vm = iotests.VM()
 371         self.vm.add_device("{},id=virtio-scsi".format('virtio-scsi'))
 372         self.vm.launch()
 373
 374     def tearDown(self):
 375         self.vm.shutdown()
 376
 377     def test_removable_media(self):
 378         # Add a couple of dummy nodes named cd0 and cd1
 379         self.vm.cmd("blockdev-add", driver="null-co",
 380                     read_zeroes=True, node_name="cd0")
 381         self.vm.cmd("blockdev-add", driver="null-co",
 382                     read_zeroes=True, node_name="cd1")
 383
 384         # Attach a CD drive with cd0 inserted
 385         self.vm.cmd("device_add", driver="scsi-cd",
 386                     id="dev0", drive="cd0")
 387
 388         # Set I/O limits
 389         args = { "id": "dev0", "iops": 100, "iops_rd": 0, "iops_wr": 0,
 390                                 "bps":  50,  "bps_rd": 0,  "bps_wr": 0 }
 391         self.vm.cmd("block_set_io_throttle", conv_keys=False, **args)
 392
 393         # Check that the I/O limits have been set
 394         result = self.vm.qmp("query-block")
 395         self.assert_qmp(result, 'return[0]/inserted/iops', 100)
 396         self.assert_qmp(result, 'return[0]/inserted/bps',   50)
 397
 398         # Now eject cd0 and insert cd1
 399         self.vm.cmd("blockdev-open-tray", id='dev0')
 400         self.vm.cmd("blockdev-remove-medium", id='dev0')
 401         self.vm.cmd("blockdev-insert-medium", id='dev0', node_name='cd1')
 402
 403         # Check that the I/O limits are still the same
 404         result = self.vm.qmp("query-block")
 405         self.assert_qmp(result, 'return[0]/inserted/iops', 100)
 406         self.assert_qmp(result, 'return[0]/inserted/bps',   50)
 407
 408         # Eject cd1
 409         self.vm.cmd("blockdev-remove-medium", id='dev0')
 410
 411         # Check that we can't set limits if the device has no medium
 412         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **args)
 413         self.assert_qmp(result, 'error/class', 'GenericError')
 414
 415         # Remove the CD drive
 416         self.vm.cmd("device_del", id='dev0')
 417
 418
 419 if __name__ == '__main__':
 420     if 'null-co' not in iotests.supported_formats():
 421         iotests.notrun('null-co driver support missing')
 422     iotests.main(supported_fmts=["raw"])