openstack/swift
Code Issues Proposed changes
85529531d6
swift/bin/swift-ring-builder
Florian Hines 00dbad0825 Add optional locking to swift-ring-builder 
If invoked as 'swift-ring-builder-safe' the directory containing the builder
file provided will be locked (via lock_parent_directory()). This provides a
small safe guard against multiple instances of the swift-ring-builder (or
other utilities that observe this lock) from attempting to write to or read
the builder/ring files while operations are in progress.

This is particularly useful in environments where ring management has been
automated (via Chef or custom solutions) but the operator still occasionally
needs to manually interact with the ring.

DocImpact

Change-Id: Ia362744a8151a91bfb586d01da582906726852e6
2013-01-25 08:00:33 -08:00

637 lines
26 KiB
Python
Executable File
Raw Blame History

#! /usr/bin/env python
# Copyright (c) 2010-2012 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 itertools import islice, izip
from os import mkdir
from os.path import basename, abspath, dirname, exists, join as pathjoin
from sys import argv, exit
from textwrap import wrap
from time import time
from swift.common import exceptions
from swift.common.ring import RingBuilder
from swift.common.utils import lock_parent_directory
MAJOR_VERSION = 1
MINOR_VERSION = 3
EXIT_SUCCESS = 0
EXIT_WARNING = 1
EXIT_ERROR = 2
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 builder.search_devs.__doc__.strip()
exit(EXIT_ERROR)
devs = builder.search_devs(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 builder.search_devs.__doc__.strip()
exit(EXIT_ERROR)
devs = []
for arg in argv[3:]:
devs.extend(builder.search_devs(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> <weight>
[z<zone>-<ip>:<port>/<device_name>_<meta> <weight>] ...
Adds devices 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 or len(argv) % 2 != 1:
print Commands.add.__doc__.strip()
exit(EXIT_ERROR)
devs_and_weights = izip(islice(argv, 3, len(argv), 2),
islice(argv, 4, len(argv), 2))
for devstr, weightstr in devs_and_weights:
if not devstr.startswith('z'):
print 'Invalid add value: %s' % devstr
exit(EXIT_ERROR)
i = 1
while i < len(devstr) and devstr[i].isdigit():
i += 1
zone = int(devstr[1:i])
rest = devstr[i:]
if not rest.startswith('-'):
print 'Invalid add value: %s' % devstr
print "The on-disk ring builder is unchanged.\n"
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' % devstr
print "The on-disk ring builder is unchanged.\n"
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' % devstr
print "The on-disk ring builder is unchanged.\n"
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:]
try:
weight = float(weightstr)
except ValueError:
print 'Invalid weight value: %s' % weightstr
print "The on-disk ring builder is unchanged.\n"
exit(EXIT_ERROR)
if weight < 0:
print 'Invalid weight value (must be positive): %s' % weightstr
print "The on-disk ring builder is unchanged.\n"
exit(EXIT_ERROR)
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'])
print "The on-disk ring builder is unchanged.\n"
exit(EXIT_ERROR)
builder.add_dev({'zone': zone, 'ip': ip, 'port': port,
'device': device_name, 'weight': weight,
'meta': meta})
new_dev = builder.search_devs(
'z%s-%s:%s/%s' % (zone, ip, port, device_name))[0]['id']
if ':' in ip:
print 'Device z%s-[%s]:%s/%s_"%s" with %s weight got id %s' % \
(zone, ip, port, device_name, meta, weight, new_dev)
else:
print 'Device z%s-%s:%s/%s_"%s" with %s weight got id %s' % \
(zone, ip, port, device_name, meta, weight, new_dev)
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>
[<search-value> <weight] ...
Resets the devices' weights. 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 or len(argv) % 2 != 1:
print Commands.set_weight.__doc__.strip()
print
print builder.search_devs.__doc__.strip()
exit(EXIT_ERROR)
devs_and_weights = izip(islice(argv, 3, len(argv), 2),
islice(argv, 4, len(argv), 2))
for devstr, weightstr in devs_and_weights:
devs = builder.search_devs(devstr)
weight = float(weightstr)
if not devs:
print("Search value \"%s\" matched 0 devices.\n"
"The on-disk ring builder is unchanged.\n"
% devstr)
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>
[<search-value> <ip>:<port>/<device_name>_<meta>] ...
For each search-value, resets the matched 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 or len(argv) % 2 != 1:
print Commands.set_info.__doc__.strip()
print
print builder.search_devs.__doc__.strip()
exit(EXIT_ERROR)
searches_and_changes = izip(islice(argv, 3, len(argv), 2),
islice(argv, 4, len(argv), 2))
for search_value, change_value in searches_and_changes:
devs = builder.search_devs(search_value)
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("Search value \"%s\" matched 0 devices.\n"
"The on-disk ring builder is unchanged.\n"
% search_value)
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> [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 builder.search_devs.__doc__.strip()
exit(EXIT_ERROR)
for search_value in argv[3:]:
devs = builder.search_devs(search_value)
if not devs:
print("Search value \"%s\" matched 0 devices.\n"
"The on-disk ring builder is unchanged." % search_value)
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\n"
"the last device in a ring. If this is the case,\n"
"consider 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()
builder.get_ring().save(
pathjoin(backup_dir, '%d.' % ts + basename(ring_file)))
pickle.dump(builder.to_dict(), open(pathjoin(backup_dir,
'%d.' % ts + basename(argv[1])), 'wb'), protocol=2)
builder.get_ring().save(ring_file)
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'
ring_data.save(
pathjoin(backup_dir, '%d.' % time() + basename(ring_file)))
ring_data.save(ring_file)
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 RingBuilder.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]):
builder = RingBuilder.load(argv[1])
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]
if argv[0].endswith('-safe'):
try:
with lock_parent_directory(abspath(argv[1]), 15):
Commands.__dict__.get(command, Commands.unknown)()
except exceptions.LockTimeout:
print "Ring/builder dir currently locked."
exit(2)
else:
Commands.__dict__.get(command, Commands.unknown)()
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