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
copy_of_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_with_routers(resolve(self.initial_address)):
return
if self.update_routing_table_with_routers(copy_of_routers):
return
if not has_tried_initial_routers:
initial_routers = resolve(self.initial_address)
for router in copy_of_routers:
if router in initial_routers:
initial_routers.remove(router)
if initial_routers:
if self.update_routing_table_with_routers(initial_routers):
return
# None of the routers have been successful, so just fail
raise ServiceUnavailable("Unable to retrieve routing information")
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
"""
try:
with RoutingSession(lambda _: self.acquire_direct(address), access_mode=None) as session:
return list(session.run("ignored", self.routing_context))
except CypherError as error:
if error.code == "Neo.ClientError.Procedure.ProcedureNotFound":
raise ServiceUnavailable("Server {!r} does not support routing".format(address))
else:
raise ServiceUnavailable("Routing support broken on server {!r}".format(address))
except ServiceUnavailable:
self.deactivate(address)
return None
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
"""
class RoutingInfoUpdateSession(Session):
def __run__(self, _, routing_context):
if ServerVersion.from_str(
self._connection.server.version).at_least_version(
3, 2):
statement, parameters = (
"CALL dbms.cluster.routing.getRoutingTable({context})",
{
"context": routing_context
})
else:
statement, parameters = "CALL dbms.cluster.routing.getServers", {}
return self._run(statement, parameters)
try:
with RoutingInfoUpdateSession(
lambda _: self.acquire_direct(address),
access_mode=None) as session:
return list(session.run("ignored", self.routing_context))
except CypherError as error:
if error.code == "Neo.ClientError.Procedure.ProcedureNotFound":
raise ServiceUnavailable(
"Server {!r} does not support routing".format(address))
else:
raise ServiceUnavailable(
"Routing support broken on server {!r}".format(address))
except ServiceUnavailable:
self.deactivate(address)
return None
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")