class documentation

A connector that looks up DNS SRV records.

RFC 2782 details how SRV records should be interpreted and selected for subsequent connection attempts. The algorithm for using the records' priority and weight is implemented in pickServer.

Method __init__ No summary
Method connect Start connection to remote server.
Method connectionFailed Undocumented
Method connectionLost Undocumented
Method disconnect Disconnect whatever our are state is.
Method getDestination Return destination this will try to connect to.
Method pickServer Pick the next server.
Method stopConnecting Stop attempting to connect.
Instance Variable connectFuncArgs Undocumented
Instance Variable connectFuncKwArgs Undocumented
Instance Variable connectFuncName Undocumented
Instance Variable connector Undocumented
Instance Variable domain Undocumented
Instance Variable factory Undocumented
Instance Variable host Undocumented
Instance Variable orderedServers List of server records that have already been tried in this round of connection attempts.
Instance Variable port Undocumented
Instance Variable protocol Undocumented
Instance Variable reactor Undocumented
Instance Variable servers List of candidate server records for future connection attempts.
Instance Variable service Undocumented
Instance Variable stopAfterDNS Undocumented
Method _cbGotServers Undocumented
Method _ebGotServers Undocumented
Method _ebServiceUnknown Connect to the default port when the service name is unknown.
Method _reallyConnect Undocumented
Instance Variable _defaultPort Undocumented
def __init__(self, reactor, service, domain, factory, protocol='tcp', connectFuncName='connectTCP', connectFuncArgs=(), connectFuncKwArgs={}, defaultPort=None): (source)
Parameters
reactorUndocumented
serviceUndocumented
domain:bytes or strThe domain to connect to. If passed as a text string, it will be encoded using idna encoding.
factoryUndocumented
protocolUndocumented
connectFuncNameUndocumented
connectFuncArgsUndocumented
connectFuncKwArgsUndocumented
defaultPort:intOptional default port number to be used when SRV lookup fails and the service name is unknown. This should be the port number associated with the service name as defined by the IANA registry.
def connect(self): (source)

Start connection to remote server.

def connectionFailed(self, reason): (source)

Undocumented

def connectionLost(self, reason): (source)

Undocumented

def disconnect(self): (source)

Disconnect whatever our are state is.

def getDestination(self): (source)

Return destination this will try to connect to.

Returns
An object which provides IAddress.
def pickServer(self): (source)

Pick the next server.

This selects the next server from the list of SRV records according to their priority and weight values, as set out by the default algorithm specified in RFC 2782.

At the beginning of a round, servers is populated with orderedServers, and the latter is made empty. servers is the list of candidates, and orderedServers is the list of servers that have already been tried.

First, all records are ordered by priority and weight in ascending order. Then for each priority level, a running sum is calculated over the sorted list of records for that priority. Then a random value between 0 and the final sum is compared to each record in order. The first record that is greater than or equal to that random value is chosen and removed from the list of candidates for this round.

Returns
tuple of native str and intA tuple of target hostname and port from the chosen DNS SRV record.
def stopConnecting(self): (source)

Stop attempting to connect.

connectFuncArgs = (source)

Undocumented

connectFuncKwArgs = (source)

Undocumented

connectFuncName = (source)

Undocumented

connector = (source)

Undocumented

Undocumented

Undocumented

Undocumented

orderedServers: list of dns.Record_SRV = (source)

List of server records that have already been tried in this round of connection attempts.

Undocumented

protocol = (source)

Undocumented

Undocumented

List of candidate server records for future connection attempts.

Undocumented

stopAfterDNS: int = (source)

Undocumented

def _cbGotServers(self, result): (source)

Undocumented

def _ebGotServers(self, failure): (source)

Undocumented

def _ebServiceUnknown(self, failure): (source)

Connect to the default port when the service name is unknown.

If no SRV records were found, the service name will be passed as the port. If resolving the name fails with error.ServiceNameUnknownError, a final attempt is done using the default port.

def _reallyConnect(self): (source)

Undocumented

_defaultPort = (source)

Undocumented