cluster.py 文件源码

def __init__(self, cluster, hosts, keyspace=None):
        self.cluster = cluster
        self.hosts = hosts
        self.keyspace = keyspace

        self._lock = RLock()
        self._pools = {}
        self._profile_manager = cluster.profile_manager
        self._metrics = cluster.metrics
        self._request_init_callbacks = []
        self._protocol_version = self.cluster.protocol_version

        self.encoder = Encoder()

        # create connection pools in parallel
        self._initial_connect_futures = set()
        for host in hosts:
            future = self.add_or_renew_pool(host, is_host_addition=False)
            if future:
                self._initial_connect_futures.add(future)

        futures = wait_futures(self._initial_connect_futures, return_when=FIRST_COMPLETED)
        while futures.not_done and not any(f.result() for f in futures.done):
            futures = wait_futures(futures.not_done, return_when=FIRST_COMPLETED)

        if not any(f.result() for f in self._initial_connect_futures):
            msg = "Unable to connect to any servers"
            if self.keyspace:
                msg += " using keyspace '%s'" % self.keyspace
            raise NoHostAvailable(msg, [h.address for h in hosts])