openstack/swift
Code Issues Proposed changes
15faa1e672
swift/bin/swift-ring-builder
Mark Gius 2f50a0798e Add more specific error messages to swift-ring-builder 
Replace existing Exceptions in ring builder with more specific exceptions.
Abstracted out some behavior in ring-builder that is likely to cause an
exception. Add try/except blocks to swift-ring-builder to catch specific
exceptions and provide the user with some information about how to deal
with the error.

This change begins to address blueprint friendly-error-messages

Change-Id: I8fc9cfa4899421fe04bba23ac52523778e902321
2011-09-27 10:20:51 -07:00

691 lines
27 KiB
Python
Executable File
Raw Blame History

#! /usr/bin/env python
# Copyright (c) 2010-2011 OpenStack, LLC.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import cPickle as pickle
from array import array
from errno import EEXIST
from gzip import GzipFile
from os import mkdir
from os.path import basename, dirname, exists, join as pathjoin
from sys import argv, exit, modules
from textwrap import wrap
from time import time
from swift.common import exceptions
from swift.common.ring import RingBuilder
MAJOR_VERSION = 1
MINOR_VERSION = 3
EXIT_SUCCESS = 0
EXIT_WARNING = 1
EXIT_ERROR = 2
def search_devs(builder, search_value):
"""
The <search-value> can be of the form:
d<device_id>z<zone>-<ip>:<port>/<device_name>_<meta>
Any part is optional, but you must include at least one part.
Examples:
d74 Matches the device id 74
z1 Matches devices in zone 1
z1-1.2.3.4 Matches devices in zone 1 with the ip 1.2.3.4
1.2.3.4 Matches devices in any zone with the ip 1.2.3.4
z1:5678 Matches devices in zone 1 using port 5678
:5678 Matches devices that use port 5678
/sdb1 Matches devices with the device name sdb1
_shiny Matches devices with shiny in the meta data
_"snet: 5.6.7.8" Matches devices with snet: 5.6.7.8 in the meta data
[::1] Matches devices in any zone with the ip ::1
z1-[::1]:5678 Matches devices in zone 1 with ip ::1 and port 5678
Most specific example:
d74z1-1.2.3.4:5678/sdb1_"snet: 5.6.7.8"
Nerd explanation:
All items require their single character prefix except the ip, in which
case the - is optional unless the device id or zone is also included.
"""
orig_search_value = search_value
match = []
if search_value.startswith('d'):
i = 1
while i < len(search_value) and search_value[i].isdigit():
i += 1
match.append(('id', int(search_value[1:i])))
search_value = search_value[i:]
if search_value.startswith('z'):
i = 1
while i < len(search_value) and search_value[i].isdigit():
i += 1
match.append(('zone', int(search_value[1:i])))
search_value = search_value[i:]
if search_value.startswith('-'):
search_value = search_value[1:]
if len(search_value) and search_value[0].isdigit():
i = 1
while i < len(search_value) and search_value[i] in '0123456789.':
i += 1
match.append(('ip', search_value[:i]))
search_value = search_value[i:]
elif len(search_value) and search_value[0] == '[':
i = 1
while i < len(search_value) and search_value[i] != ']':
i += 1
i += 1
match.append(('ip', search_value[:i].lstrip('[').rstrip(']')))
search_value = search_value[i:]
if search_value.startswith(':'):
i = 1
while i < len(search_value) and search_value[i].isdigit():
i += 1
match.append(('port', int(search_value[1:i])))
search_value = search_value[i:]
if search_value.startswith('/'):
i = 1
while i < len(search_value) and search_value[i] != '_':
i += 1
match.append(('device', search_value[1:i]))
search_value = search_value[i:]
if search_value.startswith('_'):
match.append(('meta', search_value[1:]))
search_value = ''
if search_value:
raise ValueError('Invalid <search-value>: %s' %
repr(orig_search_value))
devs = []
for dev in builder.devs:
if not dev:
continue
matched = True
for key, value in match:
if key == 'meta':
if value not in dev.get(key):
matched = False
elif dev.get(key) != value:
matched = False
if matched:
devs.append(dev)
return devs
def format_device(dev):
"""
Format a device for display.
"""
if ':' in dev['ip']:
return 'd%(id)sz%(zone)s-[%(ip)s]:%(port)s/%(device)s_"%(meta)s"' % dev
else:
return 'd%(id)sz%(zone)s-%(ip)s:%(port)s/%(device)s_"%(meta)s"' % dev
class Commands:
def unknown():
print 'Unknown command: %s' % argv[2]
exit(EXIT_ERROR)
def create():
"""
swift-ring-builder <builder_file> create <part_power> <replicas>
<min_part_hours>
Creates <builder_file> with 2^<part_power> partitions and <replicas>.
<min_part_hours> is number of hours to restrict moving a partition more
than once.
"""
if len(argv) < 6:
print Commands.create.__doc__.strip()
exit(EXIT_ERROR)
builder = RingBuilder(int(argv[3]), int(argv[4]), int(argv[5]))
backup_dir = pathjoin(dirname(argv[1]), 'backups')
try:
mkdir(backup_dir)
except OSError, err:
if err.errno != EEXIST:
raise
pickle.dump(builder.to_dict(), open(pathjoin(backup_dir,
'%d.' % time() + basename(argv[1])), 'wb'), protocol=2)
pickle.dump(builder.to_dict(), open(argv[1], 'wb'), protocol=2)
exit(EXIT_SUCCESS)
def default():
"""
swift-ring-builder <builder_file>
Shows information about the ring and the devices within.
"""
print '%s, build version %d' % (argv[1], builder.version)
zones = 0
balance = 0
if builder.devs:
zones = len(set(d['zone'] for d in builder.devs if d is not None))
balance = builder.get_balance()
print '%d partitions, %d replicas, %d zones, %d devices, %.02f ' \
'balance' % (builder.parts, builder.replicas, zones,
len([d for d in builder.devs if d]), balance)
print 'The minimum number of hours before a partition can be ' \
'reassigned is %s' % builder.min_part_hours
if builder.devs:
print 'Devices: id zone ip address port name ' \
'weight partitions balance meta'
weighted_parts = builder.parts * builder.replicas / \
sum(d['weight'] for d in builder.devs if d is not None)
for dev in builder.devs:
if dev is None:
continue
if not dev['weight']:
if dev['parts']:
balance = 999.99
else:
balance = 0
else:
balance = 100.0 * dev['parts'] / \
(dev['weight'] * weighted_parts) - 100.0
print ' %5d %5d %15s %5d %9s %6.02f %10s %7.02f %s' % \
(dev['id'], dev['zone'], dev['ip'], dev['port'],
dev['device'], dev['weight'], dev['parts'], balance,
dev['meta'])
exit(EXIT_SUCCESS)
def search():
"""
swift-ring-builder <builder_file> search <search-value>
Shows information about matching devices.
"""
if len(argv) < 4:
print Commands.search.__doc__.strip()
print
print search_devs.__doc__.strip()
exit(EXIT_ERROR)
devs = search_devs(builder, argv[3])
if not devs:
print 'No matching devices found'
exit(EXIT_ERROR)
print 'Devices: id zone ip address port name ' \
'weight partitions balance meta'
weighted_parts = builder.parts * builder.replicas / \
sum(d['weight'] for d in builder.devs if d is not None)
for dev in devs:
if not dev['weight']:
if dev['parts']:
balance = 999.99
else:
balance = 0
else:
balance = 100.0 * dev['parts'] / \
(dev['weight'] * weighted_parts) - 100.0
print ' %5d %5d %15s %5d %9s %6.02f %10s %7.02f %s' % \
(dev['id'], dev['zone'], dev['ip'], dev['port'],
dev['device'], dev['weight'], dev['parts'], balance,
dev['meta'])
exit(EXIT_SUCCESS)
def list_parts():
"""
swift-ring-builder <builder_file> list_parts <search-value> [<search-value>] ..
Returns a 2 column list of all the partitions that are assigned to any of
the devices matching the search values given. The first column is the
assigned partition number and the second column is the number of device
matches for that partition. The list is ordered from most number of matches
to least. If there are a lot of devices to match against, this command
could take a while to run.
"""
if len(argv) < 4:
print Commands.list_parts.__doc__.strip()
print
print search_devs.__doc__.strip()
exit(EXIT_ERROR)
devs = []
for arg in argv[3:]:
devs.extend(search_devs(builder, arg) or [])
if not devs:
print 'No matching devices found'
exit(EXIT_ERROR)
devs = [d['id'] for d in devs]
matches = [array('i') for x in xrange(builder.replicas)]
for part in xrange(builder.parts):
count = len([d for d in builder.get_part_devices(part)
if d['id'] in devs])
if count:
matches[builder.replicas - count].append(part)
print 'Partition Matches'
for index, parts in enumerate(matches):
for part in parts:
print '%9d %7d' % (part, builder.replicas - index)
exit(EXIT_SUCCESS)
def add():
"""
swift-ring-builder <builder_file> add z<zone>-<ip>:<port>/<device_name>_<meta>
<wght>
Adds a device to the ring with the given information. No partitions will be
assigned to the new device until after running 'rebalance'. This is so you
can make multiple device changes and rebalance them all just once.
"""
if len(argv) < 5:
print Commands.add.__doc__.strip()
exit(EXIT_ERROR)
if not argv[3].startswith('z'):
print 'Invalid add value: %s' % argv[3]
exit(EXIT_ERROR)
i = 1
while i < len(argv[3]) and argv[3][i].isdigit():
i += 1
zone = int(argv[3][1:i])
rest = argv[3][i:]
if not rest.startswith('-'):
print 'Invalid add value: %s' % argv[3]
exit(EXIT_ERROR)
i = 1
if rest[i] == '[':
i += 1
while i < len(rest) and rest[i] != ']':
i += 1
i += 1
ip = rest[1:i].lstrip('[').rstrip(']')
rest = rest[i:]
else:
while i < len(rest) and rest[i] in '0123456789.':
i += 1
ip = rest[1:i]
rest = rest[i:]
if not rest.startswith(':'):
print 'Invalid add value: %s' % argv[3]
exit(EXIT_ERROR)
i = 1
while i < len(rest) and rest[i].isdigit():
i += 1
port = int(rest[1:i])
rest = rest[i:]
if not rest.startswith('/'):
print 'Invalid add value: %s' % argv[3]
exit(EXIT_ERROR)
i = 1
while i < len(rest) and rest[i] != '_':
i += 1
device_name = rest[1:i]
rest = rest[i:]
meta = ''
if rest.startswith('_'):
meta = rest[1:]
weight = float(argv[4])
for dev in builder.devs:
if dev is None:
continue
if dev['ip'] == ip and dev['port'] == port and \
dev['device'] == device_name:
print 'Device %d already uses %s:%d/%s.' % \
(dev['id'], dev['ip'], dev['port'], dev['device'])
exit(EXIT_ERROR)
next_dev_id = 0
if builder.devs:
next_dev_id = max(d['id'] for d in builder.devs if d) + 1
builder.add_dev({'id': next_dev_id, 'zone': zone, 'ip': ip,
'port': port, 'device': device_name, 'weight': weight,
'meta': meta})
if ':' in ip:
print 'Device z%s-[%s]:%s/%s_"%s" with %s weight got id %s' % \
(zone, ip, port, device_name, meta, weight, next_dev_id)
else:
print 'Device z%s-%s:%s/%s_"%s" with %s weight got id %s' % \
(zone, ip, port, device_name, meta, weight, next_dev_id)
pickle.dump(builder.to_dict(), open(argv[1], 'wb'), protocol=2)
exit(EXIT_SUCCESS)
def set_weight():
"""
swift-ring-builder <builder_file> set_weight <search-value> <weight>
Resets the device's weight. No partitions will be reassigned to or from the
device until after running 'rebalance'. This is so you can make multiple
device changes and rebalance them all just once.
"""
if len(argv) != 5:
print Commands.set_weight.__doc__.strip()
print
print search_devs.__doc__.strip()
exit(EXIT_ERROR)
devs = search_devs(builder, argv[3])
weight = float(argv[4])
if not devs:
print 'No matching devices found'
exit(EXIT_ERROR)
if len(devs) > 1:
print 'Matched more than one device:'
for dev in devs:
print ' d%(id)sz%(zone)s-%(ip)s:%(port)s/%(device)s_' \
'"%(meta)s"' % dev
if raw_input('Are you sure you want to update the weight for '
'these %s devices? (y/N) ' % len(devs)) != 'y':
print 'Aborting device modifications'
exit(EXIT_ERROR)
for dev in devs:
builder.set_dev_weight(dev['id'], weight)
print 'd%(id)sz%(zone)s-%(ip)s:%(port)s/%(device)s_"%(meta)s" ' \
'weight set to %(weight)s' % dev
pickle.dump(builder.to_dict(), open(argv[1], 'wb'), protocol=2)
exit(EXIT_SUCCESS)
def set_info():
"""
swift-ring-builder <builder_file> set_info <search-value>
<ip>:<port>/<device_name>_<meta>
Resets the device's information. This information isn't used to assign
partitions, so you can use 'write_ring' afterward to rewrite the current
ring with the newer device information. Any of the parts are optional
in the final <ip>:<port>/<device_name>_<meta> parameter; just give what you
want to change. For instance set_info d74 _"snet: 5.6.7.8" would just
update the meta data for device id 74.
"""
if len(argv) != 5:
print Commands.set_info.__doc__.strip()
print
print search_devs.__doc__.strip()
exit(EXIT_ERROR)
devs = search_devs(builder, argv[3])
change_value = argv[4]
change = []
if len(change_value) and change_value[0].isdigit():
i = 1
while i < len(change_value) and change_value[i] in '0123456789.':
i += 1
change.append(('ip', change_value[:i]))
change_value = change_value[i:]
elif len(change_value) and change_value[0] == '[':
i = 1
while i < len(change_value) and change_value[i] != ']':
i += 1
i += 1
change.append(('ip', change_value[:i].lstrip('[').rstrip(']')))
change_value = change_value[i:]
if change_value.startswith(':'):
i = 1
while i < len(change_value) and change_value[i].isdigit():
i += 1
change.append(('port', int(change_value[1:i])))
change_value = change_value[i:]
if change_value.startswith('/'):
i = 1
while i < len(change_value) and change_value[i] != '_':
i += 1
change.append(('device', change_value[1:i]))
change_value = change_value[i:]
if change_value.startswith('_'):
change.append(('meta', change_value[1:]))
change_value = ''
if change_value or not change:
raise ValueError('Invalid set info change value: %s' %
repr(argv[4]))
if not devs:
print 'No matching devices found'
exit(EXIT_ERROR)
if len(devs) > 1:
print 'Matched more than one device:'
for dev in devs:
print ' %s' % format_device(dev)
if raw_input('Are you sure you want to update the info for '
'these %s devices? (y/N) ' % len(devs)) != 'y':
print 'Aborting device modifications'
exit(EXIT_ERROR)
for dev in devs:
orig_dev_string = format_device(dev)
test_dev = dict(dev)
for key, value in change:
test_dev[key] = value
for check_dev in builder.devs:
if not check_dev or check_dev['id'] == test_dev['id']:
continue
if check_dev['ip'] == test_dev['ip'] and \
check_dev['port'] == test_dev['port'] and \
check_dev['device'] == test_dev['device']:
print 'Device %d already uses %s:%d/%s.' % \
(check_dev['id'], check_dev['ip'], check_dev['port'],
check_dev['device'])
exit(EXIT_ERROR)
for key, value in change:
dev[key] = value
print 'Device %s is now %s' % (orig_dev_string, format_device(dev))
pickle.dump(builder.to_dict(), open(argv[1], 'wb'), protocol=2)
exit(EXIT_SUCCESS)
def remove():
"""
swift-ring-builder <builder_file> remove <search-value>
Removes the device(s) from the ring. This should normally just be used for
a device that has failed. For a device you wish to decommission, it's best
to set its weight to 0, wait for it to drain all its data, then use this
remove command. This will not take effect until after running 'rebalance'.
This is so you can make multiple device changes and rebalance them all just
once.
"""
if len(argv) < 4:
print Commands.remove.__doc__.strip()
print
print search_devs.__doc__.strip()
exit(EXIT_ERROR)
devs = search_devs(builder, argv[3])
if not devs:
print 'No matching devices found'
exit(EXIT_ERROR)
if len(devs) > 1:
print 'Matched more than one device:'
for dev in devs:
print ' d%(id)sz%(zone)s-%(ip)s:%(port)s/%(device)s_' \
'"%(meta)s"' % dev
if raw_input('Are you sure you want to remove these %s devices? '
'(y/N) ' % len(devs)) != 'y':
print 'Aborting device removals'
exit(EXIT_ERROR)
for dev in devs:
try:
builder.remove_dev(dev['id'])
except exceptions.RingBuilderError, e:
print '-' * 79
print ("An error occurred while removing device with id %d\n"
"This usually means that you attempted to remove the\n"
"last device in a ring. If this is the case, consider\n"
"creating a new ring instead.\n"
"The on-disk ring builder is unchanged\n"
"Original exception message: %s" %
(dev['id'], e.message)
)
print '-' * 79
exit(EXIT_ERROR)
print 'd%(id)sz%(zone)s-%(ip)s:%(port)s/%(device)s_"%(meta)s" ' \
'marked for removal and will be removed next rebalance.' \
% dev
pickle.dump(builder.to_dict(), open(argv[1], 'wb'), protocol=2)
exit(EXIT_SUCCESS)
def rebalance():
"""
swift-ring-builder <builder_file> rebalance
Attempts to rebalance the ring by reassigning partitions that haven't been
recently reassigned.
"""
devs_changed = builder.devs_changed
try:
last_balance = builder.get_balance()
parts, balance = builder.rebalance()
except exceptions.RingBuilderError, e:
print '-' * 79
print ("An error has occurred during ring validation. Common\n"
"causes of failure are rings that are empty or do not\n"
"have enough devices to accommodate the replica count.\n"
"Original exception message:\n %s" % e.message
)
print '-' * 79
exit(EXIT_ERROR)
if not parts:
print 'No partitions could be reassigned.'
print 'Either none need to be or none can be due to ' \
'min_part_hours [%s].' % builder.min_part_hours
exit(EXIT_WARNING)
if not devs_changed and abs(last_balance - balance) < 1:
print 'Cowardly refusing to save rebalance as it did not change ' \
'at least 1%.'
exit(EXIT_WARNING)
try:
builder.validate()
except exceptions.RingValidationError, e:
print '-' * 79
print ("An error has occurred during ring validation. Common\n"
"causes of failure are rings that are empty or do not\n"
"have enough devices to accommodate the replica count.\n"
"Original exception message:\n %s" % e.message
)
print '-' * 79
exit(EXIT_ERROR)
print 'Reassigned %d (%.02f%%) partitions. Balance is now %.02f.' % \
(parts, 100.0 * parts / builder.parts, balance)
status = EXIT_SUCCESS
if balance > 5:
print '-' * 79
print 'NOTE: Balance of %.02f indicates you should push this ' % \
balance
print ' ring, wait at least %d hours, and rebalance/repush.' \
% builder.min_part_hours
print '-' * 79
status = EXIT_WARNING
ts = time()
pickle.dump(builder.get_ring().to_dict(),
GzipFile(pathjoin(backup_dir, '%d.' % ts +
basename(ring_file)), 'wb'), protocol=2)
pickle.dump(builder.to_dict(), open(pathjoin(backup_dir,
'%d.' % ts + basename(argv[1])), 'wb'), protocol=2)
pickle.dump(builder.get_ring().to_dict(), GzipFile(ring_file, 'wb'),
protocol=2)
pickle.dump(builder.to_dict(), open(argv[1], 'wb'), protocol=2)
exit(status)
def validate():
"""
swift-ring-builder <builder_file> validate
Just runs the validation routines on the ring.
"""
builder.validate()
exit(EXIT_SUCCESS)
def write_ring():
"""
swift-ring-builder <builder_file> write_ring
Just rewrites the distributable ring file. This is done automatically after
a successful rebalance, so really this is only useful after one or more
'set_info' calls when no rebalance is needed but you want to send out the
new device information.
"""
ring_data = builder.get_ring()
if not ring_data._replica2part2dev_id:
if ring_data.devs:
print 'Warning: Writing a ring with no partition ' \
'assignments but with devices; did you forget to run ' \
'"rebalance"?'
else:
print 'Warning: Writing an empty ring'
pickle.dump(ring_data.to_dict(),
GzipFile(pathjoin(backup_dir, '%d.' % time() +
basename(ring_file)), 'wb'), protocol=2)
pickle.dump(ring_data.to_dict(), GzipFile(ring_file, 'wb'), protocol=2)
exit(EXIT_SUCCESS)
def pretend_min_part_hours_passed():
builder.pretend_min_part_hours_passed()
pickle.dump(builder.to_dict(), open(argv[1], 'wb'), protocol=2)
exit(EXIT_SUCCESS)
def set_min_part_hours():
"""
swift-ring-builder <builder_file> set_min_part_hours <hours>
Changes the <min_part_hours> to the given <hours>. This should be set to
however long a full replication/update cycle takes. We're working on a way
to determine this more easily than scanning logs.
"""
if len(argv) < 4:
print Commands.set_min_part_hours.__doc__.strip()
exit(EXIT_ERROR)
builder.change_min_part_hours(int(argv[3]))
print 'The minimum number of hours before a partition can be ' \
'reassigned is now set to %s' % argv[3]
pickle.dump(builder.to_dict(), open(argv[1], 'wb'), protocol=2)
exit(EXIT_SUCCESS)
if __name__ == '__main__':
if len(argv) < 2:
print "swift-ring-builder %(MAJOR_VERSION)s.%(MINOR_VERSION)s\n" % \
globals()
print Commands.default.__doc__.strip()
print
cmds = [c for c, f in Commands.__dict__.iteritems()
if f.__doc__ and c[0] != '_' and c != 'default']
cmds.sort()
for cmd in cmds:
print Commands.__dict__[cmd].__doc__.strip()
print
print search_devs.__doc__.strip()
print
for line in wrap(' '.join(cmds), 79, initial_indent='Quick list: ',
subsequent_indent=' '):
print line
print ('Exit codes: 0 = operation successful\n'
' 1 = operation completed with warnings\n' \
' 2 = error'
)
exit(EXIT_SUCCESS)
if exists(argv[1]):
try:
builder = pickle.load(open(argv[1], 'rb'))
if not hasattr(builder, 'devs'):
builder_dict = builder
builder = RingBuilder(1, 1, 1)
builder.copy_from(builder_dict)
except ImportError: # Happens with really old builder pickles
modules['swift.ring_builder'] = \
modules['swift.common.ring.builder']
builder = RingBuilder(1, 1, 1)
builder.copy_from(pickle.load(open(argv[1], 'rb')))
for dev in builder.devs:
if dev and 'meta' not in dev:
dev['meta'] = ''
elif len(argv) < 3 or argv[2] != 'create':
print 'Ring Builder file does not exist: %s' % argv[1]
exit(EXIT_ERROR)
backup_dir = pathjoin(dirname(argv[1]), 'backups')
try:
mkdir(backup_dir)
except OSError, err:
if err.errno != EEXIST:
raise
ring_file = argv[1]
if ring_file.endswith('.builder'):
ring_file = ring_file[:-len('.builder')]
ring_file += '.ring.gz'
if len(argv) == 2:
command = "default"
else:
command = argv[2]
Commands.__dict__.get(command, Commands.unknown)()
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