/usr/lib/python2.7/dist-packages/swift/obj/ssync_sender.py is in python-swift 2.7.0-0ubuntu2.
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#
# 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 six
from six.moves import urllib
from swift.common import bufferedhttp
from swift.common import exceptions
from swift.common import http
def encode_missing(object_hash, ts_data, ts_meta=None, ts_ctype=None):
"""
Returns a string representing the object hash, its data file timestamp
and the delta forwards to its metafile and content-type timestamps, if
non-zero, in the form:
``<hash> <ts_data> [m:<hex delta to ts_meta>[,t:<hex delta to ts_ctype>]]``
The decoder for this line is
:py:func:`~swift.obj.ssync_receiver.decode_missing`
"""
msg = ('%s %s'
% (urllib.parse.quote(object_hash),
urllib.parse.quote(ts_data.internal)))
if ts_meta and ts_meta != ts_data:
delta = ts_meta.raw - ts_data.raw
msg = '%s m:%x' % (msg, delta)
if ts_ctype and ts_ctype != ts_data:
delta = ts_ctype.raw - ts_data.raw
msg = '%s,t:%x' % (msg, delta)
return msg
def decode_wanted(parts):
"""
Parse missing_check line parts to determine which parts of local
diskfile were wanted by the receiver.
The encoder for parts is
:py:func:`~swift.obj.ssync_receiver.encode_wanted`
"""
wanted = {}
key_map = dict(d='data', m='meta')
if parts:
# receiver specified data and/or meta wanted, so use those as
# conditions for sending PUT and/or POST subrequests
for k in key_map:
if k in parts[0]:
wanted[key_map[k]] = True
if not wanted:
# assume legacy receiver which will only accept PUTs. There is no
# way to send any meta file content without morphing the timestamp
# of either the data or the metadata, so we just send data file
# content to a legacy receiver. Once the receiver gets updated we
# will be able to send it the meta file content.
wanted['data'] = True
return wanted
class Sender(object):
"""
Sends SSYNC requests to the object server.
These requests are eventually handled by
:py:mod:`.ssync_receiver` and full documentation about the
process is there.
"""
def __init__(self, daemon, node, job, suffixes, remote_check_objs=None):
self.daemon = daemon
self.df_mgr = self.daemon._diskfile_mgr
self.node = node
self.job = job
self.suffixes = suffixes
self.connection = None
self.response = None
self.response_buffer = ''
self.response_chunk_left = 0
# available_map has an entry for each object in given suffixes that
# is available to be sync'd; each entry is a hash => dict of timestamps
# of data file or tombstone file and/or meta file
self.available_map = {}
# When remote_check_objs is given in job, ssync_sender trys only to
# make sure those objects exist or not in remote.
self.remote_check_objs = remote_check_objs
# send_map has an entry for each object that the receiver wants to
# be sync'ed; each entry maps an object hash => dict of wanted parts
self.send_map = {}
self.failures = 0
def __call__(self):
"""
Perform ssync with remote node.
:returns: a 2-tuple, in the form (success, can_delete_objs) where
success is a boolean and can_delete_objs is the map of
objects that are in sync with the receiver. Each entry in
can_delete_objs maps a hash => timestamp of data file or
tombstone file
"""
if not self.suffixes:
return True, {}
try:
# Double try blocks in case our main error handler fails.
try:
# The general theme for these functions is that they should
# raise exceptions.MessageTimeout for client timeouts and
# exceptions.ReplicationException for common issues that will
# abort the replication attempt and log a simple error. All
# other exceptions will be logged with a full stack trace.
self.connect()
self.missing_check()
if self.remote_check_objs is None:
self.updates()
can_delete_obj = self.available_map
else:
# when we are initialized with remote_check_objs we don't
# *send* any requested updates; instead we only collect
# what's already in sync and safe for deletion
in_sync_hashes = (set(self.available_map.keys()) -
set(self.send_map.keys()))
can_delete_obj = dict((hash_, self.available_map[hash_])
for hash_ in in_sync_hashes)
if not self.failures:
return True, can_delete_obj
else:
return False, {}
except (exceptions.MessageTimeout,
exceptions.ReplicationException) as err:
self.daemon.logger.error(
'%s:%s/%s/%s %s', self.node.get('replication_ip'),
self.node.get('replication_port'), self.node.get('device'),
self.job.get('partition'), err)
except Exception:
# We don't want any exceptions to escape our code and possibly
# mess up the original replicator code that called us since it
# was originally written to shell out to rsync which would do
# no such thing.
self.daemon.logger.exception(
'%s:%s/%s/%s EXCEPTION in replication.Sender',
self.node.get('replication_ip'),
self.node.get('replication_port'),
self.node.get('device'), self.job.get('partition'))
finally:
self.disconnect()
except Exception:
# We don't want any exceptions to escape our code and possibly
# mess up the original replicator code that called us since it
# was originally written to shell out to rsync which would do
# no such thing.
# This particular exception handler does the minimal amount as it
# would only get called if the above except Exception handler
# failed (bad node or job data).
self.daemon.logger.exception('EXCEPTION in replication.Sender')
return False, {}
def connect(self):
"""
Establishes a connection and starts an SSYNC request
with the object server.
"""
with exceptions.MessageTimeout(
self.daemon.conn_timeout, 'connect send'):
self.connection = bufferedhttp.BufferedHTTPConnection(
'%s:%s' % (self.node['replication_ip'],
self.node['replication_port']))
self.connection.putrequest('SSYNC', '/%s/%s' % (
self.node['device'], self.job['partition']))
self.connection.putheader('Transfer-Encoding', 'chunked')
self.connection.putheader('X-Backend-Storage-Policy-Index',
int(self.job['policy']))
# a sync job must use the node's index for the frag_index of the
# rebuilt fragments instead of the frag_index from the job which
# will be rebuilding them
frag_index = self.node.get('index', self.job.get('frag_index'))
if frag_index is None:
# replication jobs will not have a frag_index key;
# reconstructor jobs with only tombstones will have a
# frag_index key explicitly set to the value of None - in both
# cases on the wire we write the empty string which
# ssync_receiver will translate to None
frag_index = ''
self.connection.putheader('X-Backend-Ssync-Frag-Index',
frag_index)
# a revert job to a handoff will not have a node index
self.connection.putheader('X-Backend-Ssync-Node-Index',
self.node.get('index', ''))
self.connection.endheaders()
with exceptions.MessageTimeout(
self.daemon.node_timeout, 'connect receive'):
self.response = self.connection.getresponse()
if self.response.status != http.HTTP_OK:
err_msg = self.response.read()[:1024]
raise exceptions.ReplicationException(
'Expected status %s; got %s (%s)' %
(http.HTTP_OK, self.response.status, err_msg))
def readline(self):
"""
Reads a line from the SSYNC response body.
httplib has no readline and will block on read(x) until x is
read, so we have to do the work ourselves. A bit of this is
taken from Python's httplib itself.
"""
data = self.response_buffer
self.response_buffer = ''
while '\n' not in data and len(data) < self.daemon.network_chunk_size:
if self.response_chunk_left == -1: # EOF-already indicator
break
if self.response_chunk_left == 0:
line = self.response.fp.readline()
i = line.find(';')
if i >= 0:
line = line[:i] # strip chunk-extensions
try:
self.response_chunk_left = int(line.strip(), 16)
except ValueError:
# close the connection as protocol synchronisation is
# probably lost
self.response.close()
raise exceptions.ReplicationException('Early disconnect')
if self.response_chunk_left == 0:
self.response_chunk_left = -1
break
chunk = self.response.fp.read(min(
self.response_chunk_left,
self.daemon.network_chunk_size - len(data)))
if not chunk:
# close the connection as protocol synchronisation is
# probably lost
self.response.close()
raise exceptions.ReplicationException('Early disconnect')
self.response_chunk_left -= len(chunk)
if self.response_chunk_left == 0:
self.response.fp.read(2) # discard the trailing \r\n
data += chunk
if '\n' in data:
data, self.response_buffer = data.split('\n', 1)
data += '\n'
return data
def missing_check(self):
"""
Handles the sender-side of the MISSING_CHECK step of a
SSYNC request.
Full documentation of this can be found at
:py:meth:`.Receiver.missing_check`.
"""
# First, send our list.
with exceptions.MessageTimeout(
self.daemon.node_timeout, 'missing_check start'):
msg = ':MISSING_CHECK: START\r\n'
self.connection.send('%x\r\n%s\r\n' % (len(msg), msg))
hash_gen = self.df_mgr.yield_hashes(
self.job['device'], self.job['partition'],
self.job['policy'], self.suffixes,
frag_index=self.job.get('frag_index'))
if self.remote_check_objs is not None:
hash_gen = six.moves.filter(
lambda path_objhash_timestamps:
path_objhash_timestamps[1] in
self.remote_check_objs, hash_gen)
for path, object_hash, timestamps in hash_gen:
self.available_map[object_hash] = timestamps
with exceptions.MessageTimeout(
self.daemon.node_timeout,
'missing_check send line'):
msg = '%s\r\n' % encode_missing(object_hash, **timestamps)
self.connection.send('%x\r\n%s\r\n' % (len(msg), msg))
with exceptions.MessageTimeout(
self.daemon.node_timeout, 'missing_check end'):
msg = ':MISSING_CHECK: END\r\n'
self.connection.send('%x\r\n%s\r\n' % (len(msg), msg))
# Now, retrieve the list of what they want.
while True:
with exceptions.MessageTimeout(
self.daemon.http_timeout, 'missing_check start wait'):
line = self.readline()
if not line:
raise exceptions.ReplicationException('Early disconnect')
line = line.strip()
if line == ':MISSING_CHECK: START':
break
elif line:
raise exceptions.ReplicationException(
'Unexpected response: %r' % line[:1024])
while True:
with exceptions.MessageTimeout(
self.daemon.http_timeout, 'missing_check line wait'):
line = self.readline()
if not line:
raise exceptions.ReplicationException('Early disconnect')
line = line.strip()
if line == ':MISSING_CHECK: END':
break
parts = line.split()
if parts:
self.send_map[parts[0]] = decode_wanted(parts[1:])
def updates(self):
"""
Handles the sender-side of the UPDATES step of an SSYNC
request.
Full documentation of this can be found at
:py:meth:`.Receiver.updates`.
"""
# First, send all our subrequests based on the send_map.
with exceptions.MessageTimeout(
self.daemon.node_timeout, 'updates start'):
msg = ':UPDATES: START\r\n'
self.connection.send('%x\r\n%s\r\n' % (len(msg), msg))
for object_hash, want in self.send_map.items():
object_hash = urllib.parse.unquote(object_hash)
try:
df = self.df_mgr.get_diskfile_from_hash(
self.job['device'], self.job['partition'], object_hash,
self.job['policy'], frag_index=self.job.get('frag_index'))
except exceptions.DiskFileNotExist:
continue
url_path = urllib.parse.quote(
'/%s/%s/%s' % (df.account, df.container, df.obj))
try:
df.open()
if want.get('data'):
# EC reconstructor may have passed a callback to build an
# alternative diskfile - construct it using the metadata
# from the data file only.
df_alt = self.job.get(
'sync_diskfile_builder', lambda *args: df)(
self.job, self.node, df.get_datafile_metadata())
self.send_put(url_path, df_alt)
if want.get('meta') and df.data_timestamp != df.timestamp:
self.send_post(url_path, df)
except exceptions.DiskFileDeleted as err:
if want.get('data'):
self.send_delete(url_path, err.timestamp)
except exceptions.DiskFileError:
pass
with exceptions.MessageTimeout(
self.daemon.node_timeout, 'updates end'):
msg = ':UPDATES: END\r\n'
self.connection.send('%x\r\n%s\r\n' % (len(msg), msg))
# Now, read their response for any issues.
while True:
with exceptions.MessageTimeout(
self.daemon.http_timeout, 'updates start wait'):
line = self.readline()
if not line:
raise exceptions.ReplicationException('Early disconnect')
line = line.strip()
if line == ':UPDATES: START':
break
elif line:
raise exceptions.ReplicationException(
'Unexpected response: %r' % line[:1024])
while True:
with exceptions.MessageTimeout(
self.daemon.http_timeout, 'updates line wait'):
line = self.readline()
if not line:
raise exceptions.ReplicationException('Early disconnect')
line = line.strip()
if line == ':UPDATES: END':
break
elif line:
raise exceptions.ReplicationException(
'Unexpected response: %r' % line[:1024])
def send_delete(self, url_path, timestamp):
"""
Sends a DELETE subrequest with the given information.
"""
msg = ['DELETE ' + url_path, 'X-Timestamp: ' + timestamp.internal]
msg = '\r\n'.join(msg) + '\r\n\r\n'
with exceptions.MessageTimeout(
self.daemon.node_timeout, 'send_delete'):
self.connection.send('%x\r\n%s\r\n' % (len(msg), msg))
def send_put(self, url_path, df):
"""
Sends a PUT subrequest for the url_path using the source df
(DiskFile) and content_length.
"""
msg = ['PUT ' + url_path, 'Content-Length: ' + str(df.content_length)]
# Sorted to make it easier to test.
for key, value in sorted(df.get_datafile_metadata().items()):
if key not in ('name', 'Content-Length'):
msg.append('%s: %s' % (key, value))
msg = '\r\n'.join(msg) + '\r\n\r\n'
with exceptions.MessageTimeout(self.daemon.node_timeout, 'send_put'):
self.connection.send('%x\r\n%s\r\n' % (len(msg), msg))
for chunk in df.reader():
with exceptions.MessageTimeout(
self.daemon.node_timeout, 'send_put chunk'):
self.connection.send('%x\r\n%s\r\n' % (len(chunk), chunk))
def send_post(self, url_path, df):
metadata = df.get_metafile_metadata()
if metadata is None:
return
msg = ['POST ' + url_path]
# Sorted to make it easier to test.
for key, value in sorted(metadata.items()):
msg.append('%s: %s' % (key, value))
msg = '\r\n'.join(msg) + '\r\n\r\n'
with exceptions.MessageTimeout(self.daemon.node_timeout, 'send_post'):
self.connection.send('%x\r\n%s\r\n' % (len(msg), msg))
def disconnect(self):
"""
Closes down the connection to the object server once done
with the SSYNC request.
"""
if not self.connection:
return
try:
with exceptions.MessageTimeout(
self.daemon.node_timeout, 'disconnect'):
self.connection.send('0\r\n\r\n')
except (Exception, exceptions.Timeout):
pass # We're okay with the above failing.
self.connection.close()
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