def _connect(resolved_address, **config):
"""
:param resolved_address:
:param config:
:return: socket object
"""
s = None
try:
if len(resolved_address) == 2:
s = socket(AF_INET)
elif len(resolved_address) == 4:
s = socket(AF_INET6)
else:
raise ValueError("Unsupported address {!r}".format(resolved_address))
t = s.gettimeout()
s.settimeout(config.get("connection_timeout", DEFAULT_CONNECTION_TIMEOUT))
log_debug("[#0000] C: <OPEN> %s", resolved_address)
s.connect(resolved_address)
s.settimeout(t)
s.setsockopt(SOL_SOCKET, SO_KEEPALIVE, 1 if config.get("keep_alive", DEFAULT_KEEP_ALIVE) else 0)
except SocketTimeout:
log_debug("[#0000] C: <TIMEOUT> %s", resolved_address)
log_debug("[#0000] C: <CLOSE> %s", resolved_address)
s.close()
raise ServiceUnavailable("Timed out trying to establish connection to {!r}".format(resolved_address))
except (IOError, OSError) as error: # TODO 2.0: remove IOError alias
log_debug("[#0000] C: <ERROR> %s %s", type(error).__name__, " ".join(map(repr, error.args)))
log_debug("[#0000] C: <CLOSE> %s", resolved_address)
s.close()
raise ServiceUnavailable("Failed to establish connection to {!r} (reason {})".format(resolved_address, error))
else:
return s
def connect(address, **config):
""" Connect and perform a handshake and return a valid Connection object, assuming
a protocol version can be agreed.
"""
security_plan = SecurityPlan.build(**config)
last_error = None
# Establish a connection to the host and port specified
# Catches refused connections see:
# https://docs.python.org/2/library/errno.html
log_debug("[#0000] C: <RESOLVE> %s", address)
resolver = Resolver(custom_resolver=config.get("resolver"))
resolver.addresses.append(address)
resolver.custom_resolve()
resolver.dns_resolve()
for resolved_address in resolver.addresses:
try:
s = _connect(resolved_address, **config)
s, der_encoded_server_certificate = _secure(
s, address[0], security_plan.ssl_context, **config)
connection = _handshake(s, resolved_address,
der_encoded_server_certificate, **config)
except Exception as error:
last_error = error
else:
return connection
if last_error is None:
raise ServiceUnavailable("Failed to resolve addresses for %s" %
address)
else:
raise last_error
def on_failure(self, metadata):
code = metadata.get("code")
message = metadata.get("message", "Connection initialisation failed")
if code == "Neo.ClientError.Security.Unauthorized":
raise AuthError(message)
else:
raise ServiceUnavailable(message)
def acquire_direct(self, address):
""" Acquire a connection to a given address from the pool.
The address supplied should always be an IP address, not
a host name.
This method is thread safe.
"""
if self.closed():
raise ServiceUnavailable("Connection pool closed")
with self.lock:
try:
connections = self.connections[address]
except KeyError:
connections = self.connections[address] = deque()
connection_acquisition_start_timestamp = perf_counter()
while True:
# try to find a free connection in pool
for connection in list(connections):
if connection.closed() or connection.defunct(
) or connection.timedout():
connections.remove(connection)
continue
if not connection.in_use:
connection.in_use = True
return connection
# all connections in pool are in-use
can_create_new_connection = self._max_connection_pool_size == INFINITE or len(
connections) < self._max_connection_pool_size
if can_create_new_connection:
try:
connection = self.connector(
address,
error_handler=self.connection_error_handler)
except ServiceUnavailable:
self.remove(address)
raise
else:
connection.pool = self
connection.in_use = True
connections.append(connection)
return connection
# failed to obtain a connection from pool because the pool is full and no free connection in the pool
span_timeout = self._connection_acquisition_timeout - (
perf_counter() - connection_acquisition_start_timestamp)
if span_timeout > 0:
self.cond.wait(span_timeout)
# if timed out, then we throw error. This time computation is needed, as with python 2.7, we cannot
# tell if the condition is notified or timed out when we come to this line
if self._connection_acquisition_timeout <= (
perf_counter() -
connection_acquisition_start_timestamp):
raise ClientError(
"Failed to obtain a connection from pool within {!r}s"
.format(self._connection_acquisition_timeout))
else:
raise ClientError(
"Failed to obtain a connection from pool within {!r}s".
format(self._connection_acquisition_timeout))
def fetch_routing_info(self, address):
""" Fetch raw routing info from a given router address.
:param address: router address
:return: list of routing records or
None if no connection could be established
:raise ServiceUnavailable: if the server does not support routing or
if routing support is broken
"""
metadata = {}
records = []
def fail(md):
if md.get("code") == "Neo.ClientError.Procedure.ProcedureNotFound":
raise RoutingProtocolError("Server {!r} does not support routing".format(address))
else:
raise RoutingProtocolError("Routing support broken on server {!r}".format(address))
try:
with self.acquire_direct(address) as cx:
_, _, server_version = (cx.server.agent or "").partition("/")
if server_version and Version.parse(server_version) >= Version((3, 2)):
cx.run("CALL dbms.cluster.routing.getRoutingTable({context})",
{"context": self.routing_context}, on_success=metadata.update, on_failure=fail)
else:
cx.run("CALL dbms.cluster.routing.getServers", {}, on_success=metadata.update, on_failure=fail)
cx.pull_all(on_success=metadata.update, on_records=records.extend)
cx.sync()
except RoutingProtocolError as error:
raise ServiceUnavailable(*error.args)
except ServiceUnavailable:
self.deactivate(address)
return None
else:
return [dict(zip(metadata.get("fields", ()), values)) for values in records]
def _run_transaction(self, access_mode, unit_of_work, *args, **kwargs):
from neobolt.exceptions import ConnectionExpired, TransientError, ServiceUnavailable
if not callable(unit_of_work):
raise TypeError("Unit of work is not callable")
metadata = getattr(unit_of_work, "metadata", None)
timeout = getattr(unit_of_work, "timeout", None)
retry_delay = retry_delay_generator(INITIAL_RETRY_DELAY,
RETRY_DELAY_MULTIPLIER,
RETRY_DELAY_JITTER_FACTOR)
errors = []
t0 = perf_counter()
while True:
try:
self._open_transaction(access_mode, metadata, timeout)
tx = self._transaction
try:
result = unit_of_work(tx, *args, **kwargs)
except Exception:
tx.success = False
raise
else:
if tx.success is None:
tx.success = True
finally:
tx.close()
except (ServiceUnavailable, SessionExpired,
ConnectionExpired) as error:
errors.append(error)
except TransientError as error:
if is_retriable_transient_error(error):
errors.append(error)
else:
raise
else:
return result
t1 = perf_counter()
if t1 - t0 > self._max_retry_time:
break
delay = next(retry_delay)
log.warning("Transaction failed and will be retried in {}s "
"({})".format(delay, "; ".join(errors[-1].args)))
sleep(delay)
if errors:
raise errors[-1]
else:
raise ServiceUnavailable("Transaction failed")
def _run_transaction(self, access_mode, unit_of_work, *args, **kwargs):
from neobolt.exceptions import ConnectionExpired, TransientError, ServiceUnavailable
if not callable(unit_of_work):
raise TypeError("Unit of work is not callable")
retry_delay = retry_delay_generator(INITIAL_RETRY_DELAY,
RETRY_DELAY_MULTIPLIER,
RETRY_DELAY_JITTER_FACTOR)
errors = []
t0 = perf_counter()
while True:
try:
self._open_transaction(access_mode)
tx = self._transaction
try:
result = unit_of_work(tx, *args, **kwargs)
except:
if tx.success is None:
tx.success = False
raise
else:
if tx.success is None:
tx.success = True
finally:
tx.close()
except (ServiceUnavailable, SessionExpired, ConnectionExpired) as error:
errors.append(error)
except TransientError as error:
if is_retriable_transient_error(error):
errors.append(error)
else:
raise
else:
return result
t1 = perf_counter()
if t1 - t0 > self._max_retry_time:
break
sleep(next(retry_delay))
if errors:
raise errors[-1]
else:
raise ServiceUnavailable("Transaction failed")
def update_routing_table(self):
""" Update the routing table from the first router able to provide
valid routing information.
"""
# copied because it can be modified
existing_routers = list(self.routing_table.routers)
has_tried_initial_routers = False
if self.missing_writer:
has_tried_initial_routers = True
if self.update_routing_table_from(self.initial_address):
return
if self.update_routing_table_from(*existing_routers):
return
if not has_tried_initial_routers and self.initial_address not in existing_routers:
if self.update_routing_table_from(self.initial_address):
return
# None of the routers have been successful, so just fail
raise ServiceUnavailable("Unable to retrieve routing information")
def commit_transaction(self):
""" Commit the current transaction.
:returns: the bookmark returned from the server, if any
:raise: :class:`.TransactionError` if no transaction is currently open
"""
self._assert_open()
if not self._transaction:
raise TransactionError("No transaction to commit")
metadata = {}
try:
self._connection.commit(on_success=metadata.update)
self._connection.send_all()
self._connection.fetch_all()
except IncompleteCommitError:
raise ServiceUnavailable("Connection closed during commit")
finally:
self._disconnect()
self._transaction = None
bookmark = metadata.get("bookmark")
self._bookmarks_in = tuple([bookmark])
self._bookmark_out = bookmark
return bookmark
def _handshake(s, resolved_address, der_encoded_server_certificate, **config):
"""
:param s:
:return:
"""
local_port = s.getsockname()[1]
# Send details of the protocol versions supported
supported_versions = [3, 2, 1, 0]
handshake = [MAGIC_PREAMBLE] + supported_versions
log_debug("[#%04X] C: <MAGIC> 0x%08X", local_port, MAGIC_PREAMBLE)
log_debug("[#%04X] C: <HANDSHAKE> 0x%08X 0x%08X 0x%08X 0x%08X",
local_port, *supported_versions)
data = b"".join(struct_pack(">I", num) for num in handshake)
s.sendall(data)
# Handle the handshake response
ready_to_read = False
while not ready_to_read:
ready_to_read, _, _ = select((s, ), (), (), 1)
try:
data = s.recv(4)
except (IOError, OSError): # TODO 2.0: remove IOError alias
raise ServiceUnavailable(
"Failed to read any data from server {!r} after connected".format(
resolved_address))
data_size = len(data)
if data_size == 0:
# If no data is returned after a successful select
# response, the server has closed the connection
log_debug("[#%04X] S: <CLOSE>", local_port)
s.close()
raise ServiceUnavailable(
"Connection to %r closed without handshake response" %
(resolved_address, ))
if data_size != 4:
# Some garbled data has been received
log_debug("[#%04X] S: @*#!", local_port)
s.close()
raise ProtocolError(
"Expected four byte Bolt handshake response from %r, received %r instead; "
"check for incorrect port number" % (resolved_address, data))
agreed_version, = struct_unpack(">I", data)
log_debug("[#%04X] S: <HANDSHAKE> 0x%08X", local_port, agreed_version)
if agreed_version == 0:
log_debug("[#%04X] C: <CLOSE>", local_port)
s.shutdown(SHUT_RDWR)
s.close()
elif agreed_version in (1, 2):
connection = Connection(
agreed_version,
resolved_address,
s,
der_encoded_server_certificate=der_encoded_server_certificate,
**config)
connection.init()
return connection
elif agreed_version in (3, ):
connection = Connection(
agreed_version,
resolved_address,
s,
der_encoded_server_certificate=der_encoded_server_certificate,
**config)
connection.hello()
return connection
elif agreed_version == 0x48545450:
log_debug("[#%04X] S: <CLOSE>", local_port)
s.close()
raise ServiceUnavailable("Cannot to connect to Bolt service on {!r} "
"(looks like HTTP)".format(resolved_address))
else:
log_debug("[#%04X] S: <CLOSE>", local_port)
s.close()
raise ProtocolError(
"Unknown Bolt protocol version: {}".format(agreed_version))
