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             result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
  59             self.assert_qmp(result, 'return', {})
  60
  61     def do_test_throttle(self, ndrives, seconds, params, first_drive = 0):
  62         def check_limit(limit, num):
  63             # IO throttling algorithm is discrete, allow 10% error so the test
  64             # is more robust
  65             return limit == 0 or \
  66                    (num < seconds * limit * 1.1 / ndrives
  67                    and num > seconds * limit * 0.9 / ndrives)
  68
  69         # Set vm clock to a known value
  70         ns = seconds * nsec_per_sec
  71         self.vm.qtest("clock_step %d" % ns)
  72
  73         # Submit enough requests so the throttling mechanism kicks
  74         # in. The throttled requests won't be executed until we
  75         # advance the virtual clock.
  76         rq_size = 512
  77         rd_nr = max(params['bps'] // rq_size // 2,
  78                     params['bps_rd'] // rq_size,
  79                     params['iops'] // 2,
  80                     params['iops_rd'])
  81         rd_nr *= seconds * 2
  82         rd_nr //= ndrives
  83         wr_nr = max(params['bps'] // rq_size // 2,
  84                     params['bps_wr'] // rq_size,
  85                     params['iops'] // 2,
  86                     params['iops_wr'])
  87         wr_nr *= seconds * 2
  88         wr_nr //= ndrives
  89
  90         # Send I/O requests to all drives
  91         for i in range(rd_nr):
  92             for drive in range(0, ndrives):
  93                 idx = first_drive + drive
  94                 self.vm.hmp_qemu_io("drive%d" % idx, "aio_read %d %d" %
  95                                     (i * rq_size, rq_size))
  96
  97         for i in range(wr_nr):
  98             for drive in range(0, ndrives):
  99                 idx = first_drive + drive
 100                 self.vm.hmp_qemu_io("drive%d" % idx, "aio_write %d %d" %
 101                                     (i * rq_size, rq_size))
 102
 103         # We'll store the I/O stats for each drive in these arrays
 104         start_rd_bytes = [0] * ndrives
 105         start_rd_iops  = [0] * ndrives
 106         start_wr_bytes = [0] * ndrives
 107         start_wr_iops  = [0] * ndrives
 108         end_rd_bytes   = [0] * ndrives
 109         end_rd_iops    = [0] * ndrives
 110         end_wr_bytes   = [0] * ndrives
 111         end_wr_iops    = [0] * ndrives
 112
 113         # Read the stats before advancing the clock
 114         for i in range(0, ndrives):
 115             idx = first_drive + i
 116             start_rd_bytes[i], start_rd_iops[i], start_wr_bytes[i], \
 117                 start_wr_iops[i] = self.blockstats('drive%d' % idx)
 118
 119         self.vm.qtest("clock_step %d" % ns)
 120
 121         # Read the stats after advancing the clock
 122         for i in range(0, ndrives):
 123             idx = first_drive + i
 124             end_rd_bytes[i], end_rd_iops[i], end_wr_bytes[i], \
 125                 end_wr_iops[i] = self.blockstats('drive%d' % idx)
 126
 127         # Check that the I/O is within the limits and evenly distributed
 128         for i in range(0, ndrives):
 129             rd_bytes = end_rd_bytes[i] - start_rd_bytes[i]
 130             rd_iops = end_rd_iops[i] - start_rd_iops[i]
 131             wr_bytes = end_wr_bytes[i] - start_wr_bytes[i]
 132             wr_iops = end_wr_iops[i] - start_wr_iops[i]
 133
 134             self.assertTrue(check_limit(params['bps'], rd_bytes + wr_bytes))
 135             self.assertTrue(check_limit(params['bps_rd'], rd_bytes))
 136             self.assertTrue(check_limit(params['bps_wr'], wr_bytes))
 137             self.assertTrue(check_limit(params['iops'], rd_iops + wr_iops))
 138             self.assertTrue(check_limit(params['iops_rd'], rd_iops))
 139             self.assertTrue(check_limit(params['iops_wr'], wr_iops))
 140
 141         # Allow remaining requests to finish.  We submitted twice as many to
 142         # ensure the throttle limit is reached.
 143         self.vm.qtest("clock_step %d" % ns)
 144
 145     # Connect N drives to a VM and test I/O in all of them
 146     def test_all(self):
 147         params = {"bps": 4096,
 148                   "bps_rd": 4096,
 149                   "bps_wr": 4096,
 150                   "iops": 10,
 151                   "iops_rd": 10,
 152                   "iops_wr": 10,
 153                  }
 154         # Repeat the test with different numbers of drives
 155         for ndrives in range(1, self.max_drives + 1):
 156             # Pick each out of all possible params and test
 157             for tk in params:
 158                 limits = dict([(k, 0) for k in params])
 159                 limits[tk] = params[tk] * ndrives
 160                 self.configure_throttle(ndrives, limits)
 161                 self.do_test_throttle(ndrives, 5, limits)
 162
 163     # Connect N drives to a VM and test I/O in just one of them a time
 164     def test_one(self):
 165         params = {"bps": 4096,
 166                   "bps_rd": 4096,
 167                   "bps_wr": 4096,
 168                   "iops": 10,
 169                   "iops_rd": 10,
 170                   "iops_wr": 10,
 171                  }
 172         # Repeat the test for each one of the drives
 173         for drive in range(0, self.max_drives):
 174             # Pick each out of all possible params and test
 175             for tk in params:
 176                 limits = dict([(k, 0) for k in params])
 177                 limits[tk] = params[tk] * self.max_drives
 178                 self.configure_throttle(self.max_drives, limits)
 179                 self.do_test_throttle(1, 5, limits, drive)
 180
 181     def test_burst(self):
 182         params = {"bps": 4096,
 183                   "bps_rd": 4096,
 184                   "bps_wr": 4096,
 185                   "iops": 10,
 186                   "iops_rd": 10,
 187                   "iops_wr": 10,
 188                  }
 189         ndrives = 1
 190         # Pick each out of all possible params and test
 191         for tk in params:
 192             rate = params[tk] * ndrives
 193             burst_rate = rate * 7
 194             burst_length = 4
 195
 196             # Configure the throttling settings
 197             settings = dict([(k, 0) for k in params])
 198             settings[tk] = rate
 199             settings['%s_max' % tk] = burst_rate
 200             settings['%s_max_length' % tk] = burst_length
 201             self.configure_throttle(ndrives, settings)
 202
 203             # Wait for the bucket to empty so we can do bursts
 204             wait_ns = nsec_per_sec * burst_length * burst_rate // rate
 205             self.vm.qtest("clock_step %d" % wait_ns)
 206
 207             # Test I/O at the max burst rate
 208             limits = dict([(k, 0) for k in params])
 209             limits[tk] = burst_rate
 210             self.do_test_throttle(ndrives, burst_length, limits)
 211
 212             # Now test I/O at the normal rate
 213             limits[tk] = rate
 214             self.do_test_throttle(ndrives, 5, limits)
 215
 216     # Test that removing a drive from a throttle group should not
 217     # affect the remaining members of the group.
 218     # https://bugzilla.redhat.com/show_bug.cgi?id=1535914
 219     def test_remove_group_member(self):
 220         # Create a throttle group with two drives
 221         # and set a 4 KB/s read limit.
 222         params = {"bps": 0,
 223                   "bps_rd": 4096,
 224                   "bps_wr": 0,
 225                   "iops": 0,
 226                   "iops_rd": 0,
 227                   "iops_wr": 0 }
 228         self.configure_throttle(2, params)
 229
 230         # Read 4KB from drive0. This is performed immediately.
 231         self.vm.hmp_qemu_io("drive0", "aio_read 0 4096")
 232
 233         # Read 2KB. The I/O limit has been exceeded so this
 234         # request is throttled and a timer is set to wake it up.
 235         self.vm.hmp_qemu_io("drive0", "aio_read 0 2048")
 236
 237         # Read 2KB again. We're still over the I/O limit so this is
 238         # request is also throttled, but no new timer is set since
 239         # there's already one.
 240         self.vm.hmp_qemu_io("drive0", "aio_read 0 2048")
 241
 242         # Read from drive1. This request is also throttled, and no
 243         # timer is set in drive1 because there's already one in
 244         # drive0.
 245         self.vm.hmp_qemu_io("drive1", "aio_read 0 4096")
 246
 247         # At this point only the first 4KB have been read from drive0.
 248         # The other requests are throttled.
 249         self.assertEqual(self.blockstats('drive0')[0], 4096)
 250         self.assertEqual(self.blockstats('drive1')[0], 0)
 251
 252         # Remove drive0 from the throttle group and disable its I/O limits.
 253         # drive1 remains in the group with a throttled request.
 254         params['bps_rd'] = 0
 255         params['device'] = 'drive0'
 256         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
 257         self.assert_qmp(result, 'return', {})
 258
 259         # Removing the I/O limits from drive0 drains its two pending requests.
 260         # The read request in drive1 is still throttled.
 261         self.assertEqual(self.blockstats('drive0')[0], 8192)
 262         self.assertEqual(self.blockstats('drive1')[0], 0)
 263
 264         # Advance the clock 5 seconds. This completes the request in drive1
 265         self.vm.qtest("clock_step %d" % (5 * nsec_per_sec))
 266
 267         # Now all requests have been processed.
 268         self.assertEqual(self.blockstats('drive0')[0], 8192)
 269         self.assertEqual(self.blockstats('drive1')[0], 4096)
 270
 271 class ThrottleTestCoroutine(ThrottleTestCase):
 272     test_driver = "null-co"
 273
 274 class ThrottleTestGroupNames(iotests.QMPTestCase):
 275     max_drives = 3
 276
 277     def setUp(self):
 278         self.vm = iotests.VM()
 279         for i in range(0, self.max_drives):
 280             self.vm.add_drive("null-co://",
 281                               "throttling.iops-total=100,file.read-zeroes=on")
 282         self.vm.launch()
 283
 284     def tearDown(self):
 285         self.vm.shutdown()
 286
 287     def set_io_throttle(self, device, params):
 288         params["device"] = device
 289         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
 290         self.assert_qmp(result, 'return', {})
 291
 292     def verify_name(self, device, name):
 293         result = self.vm.qmp("query-block")
 294         for r in result["return"]:
 295             if r["device"] == device:
 296                 info = r["inserted"]
 297                 if name:
 298                     self.assertEqual(info["group"], name)
 299                 else:
 300                     self.assertFalse('group' in info)
 301                 return
 302
 303         raise Exception("No group information found for '%s'" % device)
 304
 305     def test_group_naming(self):
 306         params = {"bps": 0,
 307                   "bps_rd": 0,
 308                   "bps_wr": 0,
 309                   "iops": 0,
 310                   "iops_rd": 0,
 311                   "iops_wr": 0}
 312
 313         # Check the drives added using the command line.
 314         # The default throttling group name is the device name.
 315         for i in range(self.max_drives):
 316             devname = "drive%d" % i
 317             self.verify_name(devname, devname)
 318
 319         # Clear throttling settings => the group name is gone.
 320         for i in range(self.max_drives):
 321             devname = "drive%d" % i
 322             self.set_io_throttle(devname, params)
 323             self.verify_name(devname, None)
 324
 325         # Set throttling settings using block_set_io_throttle and
 326         # check the default group names.
 327         params["iops"] = 10
 328         for i in range(self.max_drives):
 329             devname = "drive%d" % i
 330             self.set_io_throttle(devname, params)
 331             self.verify_name(devname, devname)
 332
 333         # Set a custom group name for each device
 334         for i in range(3):
 335             devname = "drive%d" % i
 336             groupname = "group%d" % i
 337             params['group'] = groupname
 338             self.set_io_throttle(devname, params)
 339             self.verify_name(devname, groupname)
 340
 341         # Put drive0 in group1 and check that all other devices remain
 342         # unchanged
 343         params['group'] = 'group1'
 344         self.set_io_throttle('drive0', params)
 345         self.verify_name('drive0', 'group1')
 346         for i in range(1, self.max_drives):
 347             devname = "drive%d" % i
 348             groupname = "group%d" % i
 349             self.verify_name(devname, groupname)
 350
 351         # Put drive0 in group2 and check that all other devices remain
 352         # unchanged
 353         params['group'] = 'group2'
 354         self.set_io_throttle('drive0', params)
 355         self.verify_name('drive0', 'group2')
 356         for i in range(1, self.max_drives):
 357             devname = "drive%d" % i
 358             groupname = "group%d" % i
 359             self.verify_name(devname, groupname)
 360
 361         # Clear throttling settings from drive0 check that all other
 362         # devices remain unchanged
 363         params["iops"] = 0
 364         self.set_io_throttle('drive0', params)
 365         self.verify_name('drive0', None)
 366         for i in range(1, self.max_drives):
 367             devname = "drive%d" % i
 368             groupname = "group%d" % i
 369             self.verify_name(devname, groupname)
 370
 371 class ThrottleTestRemovableMedia(iotests.QMPTestCase):
 372     def setUp(self):
 373         self.vm = iotests.VM()
 374         self.vm.add_device("{},id=virtio-scsi".format('virtio-scsi'))
 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"])