tests/qemu-iotests/093

   1 #!/usr/bin/env python
   2 #
   3 # Tests for IO throttling
   4 #
   5 # Copyright (C) 2015 Red Hat, Inc.
   6 # Copyright (C) 2015-2016 Igalia, S.L.
   7 #
   8 # This program is free software; you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation; either version 2 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # This program is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 #
  21
  22 import iotests
  23
  24 nsec_per_sec = 1000000000
  25
  26 class ThrottleTestCase(iotests.QMPTestCase):
  27     test_driver = "null-aio"
  28     max_drives = 3
  29
  30     def blockstats(self, device):
  31         result = self.vm.qmp("query-blockstats")
  32         for r in result['return']:
  33             if r['device'] == device:
  34                 stat = r['stats']
  35                 return stat['rd_bytes'], stat['rd_operations'], stat['wr_bytes'], stat['wr_operations']
  36         raise Exception("Device not found for blockstats: %s" % device)
  37
  38     def required_drivers(self):
  39         return [self.test_driver]
  40
  41     @iotests.skip_if_unsupported(required_drivers)
  42     def setUp(self):
  43         self.vm = iotests.VM()
  44         for i in range(0, self.max_drives):
  45             self.vm.add_drive(self.test_driver + "://", "file.read-zeroes=on")
  46         self.vm.launch()
  47
  48     def tearDown(self):
  49         self.vm.shutdown()
  50
  51     def configure_throttle(self, ndrives, params):
  52         params['group'] = 'test'
  53
  54         # Set the I/O throttling parameters to all drives
  55         for i in range(0, ndrives):
  56             params['device'] = 'drive%d' % i
  57             result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
  58             self.assert_qmp(result, 'return', {})
  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         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
 256         self.assert_qmp(result, 'return', {})
 257
 258         # Removing the I/O limits from drive0 drains its two pending requests.
 259         # The read request in drive1 is still throttled.
 260         self.assertEqual(self.blockstats('drive0')[0], 8192)
 261         self.assertEqual(self.blockstats('drive1')[0], 0)
 262
 263         # Advance the clock 5 seconds. This completes the request in drive1
 264         self.vm.qtest("clock_step %d" % (5 * nsec_per_sec))
 265
 266         # Now all requests have been processed.
 267         self.assertEqual(self.blockstats('drive0')[0], 8192)
 268         self.assertEqual(self.blockstats('drive1')[0], 4096)
 269
 270 class ThrottleTestCoroutine(ThrottleTestCase):
 271     test_driver = "null-co"
 272
 273 class ThrottleTestGroupNames(iotests.QMPTestCase):
 274     max_drives = 3
 275
 276     def setUp(self):
 277         self.vm = iotests.VM()
 278         for i in range(0, self.max_drives):
 279             self.vm.add_drive("null-co://",
 280                               "throttling.iops-total=100,file.read-zeroes=on")
 281         self.vm.launch()
 282
 283     def tearDown(self):
 284         self.vm.shutdown()
 285
 286     def set_io_throttle(self, device, params):
 287         params["device"] = device
 288         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
 289         self.assert_qmp(result, 'return', {})
 290
 291     def verify_name(self, device, name):
 292         result = self.vm.qmp("query-block")
 293         for r in result["return"]:
 294             if r["device"] == device:
 295                 info = r["inserted"]
 296                 if name:
 297                     self.assertEqual(info["group"], name)
 298                 else:
 299                     self.assertFalse('group' in info)
 300                 return
 301
 302         raise Exception("No group information found for '%s'" % device)
 303
 304     def test_group_naming(self):
 305         params = {"bps": 0,
 306                   "bps_rd": 0,
 307                   "bps_wr": 0,
 308                   "iops": 0,
 309                   "iops_rd": 0,
 310                   "iops_wr": 0}
 311
 312         # Check the drives added using the command line.
 313         # The default throttling group name is the device name.
 314         for i in range(self.max_drives):
 315             devname = "drive%d" % i
 316             self.verify_name(devname, devname)
 317
 318         # Clear throttling settings => the group name is gone.
 319         for i in range(self.max_drives):
 320             devname = "drive%d" % i
 321             self.set_io_throttle(devname, params)
 322             self.verify_name(devname, None)
 323
 324         # Set throttling settings using block_set_io_throttle and
 325         # check the default group names.
 326         params["iops"] = 10
 327         for i in range(self.max_drives):
 328             devname = "drive%d" % i
 329             self.set_io_throttle(devname, params)
 330             self.verify_name(devname, devname)
 331
 332         # Set a custom group name for each device
 333         for i in range(3):
 334             devname = "drive%d" % i
 335             groupname = "group%d" % i
 336             params['group'] = groupname
 337             self.set_io_throttle(devname, params)
 338             self.verify_name(devname, groupname)
 339
 340         # Put drive0 in group1 and check that all other devices remain
 341         # unchanged
 342         params['group'] = 'group1'
 343         self.set_io_throttle('drive0', params)
 344         self.verify_name('drive0', 'group1')
 345         for i in range(1, self.max_drives):
 346             devname = "drive%d" % i
 347             groupname = "group%d" % i
 348             self.verify_name(devname, groupname)
 349
 350         # Put drive0 in group2 and check that all other devices remain
 351         # unchanged
 352         params['group'] = 'group2'
 353         self.set_io_throttle('drive0', params)
 354         self.verify_name('drive0', 'group2')
 355         for i in range(1, self.max_drives):
 356             devname = "drive%d" % i
 357             groupname = "group%d" % i
 358             self.verify_name(devname, groupname)
 359
 360         # Clear throttling settings from drive0 check that all other
 361         # devices remain unchanged
 362         params["iops"] = 0
 363         self.set_io_throttle('drive0', params)
 364         self.verify_name('drive0', None)
 365         for i in range(1, self.max_drives):
 366             devname = "drive%d" % i
 367             groupname = "group%d" % i
 368             self.verify_name(devname, groupname)
 369
 370 class ThrottleTestRemovableMedia(iotests.QMPTestCase):
 371     def setUp(self):
 372         self.vm = iotests.VM()
 373         self.vm.add_device("{},id=virtio-scsi".format(
 374             iotests.get_virtio_scsi_device()))
 375         self.vm.launch()
 376
 377     def tearDown(self):
 378         self.vm.shutdown()
 379
 380     def test_removable_media(self):
 381         # Add a couple of dummy nodes named cd0 and cd1
 382         result = self.vm.qmp("blockdev-add", driver="null-co",
 383                              read_zeroes=True, node_name="cd0")
 384         self.assert_qmp(result, 'return', {})
 385         result = self.vm.qmp("blockdev-add", driver="null-co",
 386                              read_zeroes=True, node_name="cd1")
 387         self.assert_qmp(result, 'return', {})
 388
 389         # Attach a CD drive with cd0 inserted
 390         result = self.vm.qmp("device_add", driver="scsi-cd",
 391                              id="dev0", drive="cd0")
 392         self.assert_qmp(result, 'return', {})
 393
 394         # Set I/O limits
 395         args = { "id": "dev0", "iops": 100, "iops_rd": 0, "iops_wr": 0,
 396                                 "bps":  50,  "bps_rd": 0,  "bps_wr": 0 }
 397         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **args)
 398         self.assert_qmp(result, 'return', {})
 399
 400         # Check that the I/O limits have been set
 401         result = self.vm.qmp("query-block")
 402         self.assert_qmp(result, 'return[0]/inserted/iops', 100)
 403         self.assert_qmp(result, 'return[0]/inserted/bps',   50)
 404
 405         # Now eject cd0 and insert cd1
 406         result = self.vm.qmp("blockdev-open-tray", id='dev0')
 407         self.assert_qmp(result, 'return', {})
 408         result = self.vm.qmp("blockdev-remove-medium", id='dev0')
 409         self.assert_qmp(result, 'return', {})
 410         result = self.vm.qmp("blockdev-insert-medium", id='dev0', node_name='cd1')
 411         self.assert_qmp(result, 'return', {})
 412
 413         # Check that the I/O limits are still the same
 414         result = self.vm.qmp("query-block")
 415         self.assert_qmp(result, 'return[0]/inserted/iops', 100)
 416         self.assert_qmp(result, 'return[0]/inserted/bps',   50)
 417
 418         # Eject cd1
 419         result = self.vm.qmp("blockdev-remove-medium", id='dev0')
 420         self.assert_qmp(result, 'return', {})
 421
 422         # Check that we can't set limits if the device has no medium
 423         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **args)
 424         self.assert_qmp(result, 'error/class', 'GenericError')
 425
 426         # Remove the CD drive
 427         result = self.vm.qmp("device_del", id='dev0')
 428         self.assert_qmp(result, 'return', {})
 429
 430
 431 if __name__ == '__main__':
 432     if 'null-co' not in iotests.supported_formats():
 433         iotests.notrun('null-co driver support missing')
 434     iotests.main(supported_fmts=["raw"])