compute和schedule通过scheduler_client进行rpc通讯

compute和schedule 节点之前都是通过rpc来通讯的，例如在E:\nova\nova\compute\manager.py 中一般通过self.scheduler_client来和schedule 通讯，例如下面的例子    def _update_scheduler_instance_info(self, context, instance):        """Sends an InstanceList with created or updated Instance objects to        the Scheduler client.        In the case of init_host, the value passed will already be an        InstanceList. Other calls will send individual Instance objects that        have been created or resized. In this case, we create an InstanceList        object containing that Instance.        """        if not self.send_instance_updates:            return        if isinstance(instance, obj_instance.Instance):            instance = objects.InstanceList(objects=[instance])        context = context.elevated()        self.scheduler_client.update_instance_info(context, self.host,                                                   instance)这里的scheduler_client在ComputeManager的__init__ 中赋值class ComputeManager(manager.Manager):    """Manages the running instances from creation to destruction."""    target = messaging.Target(version='4.18')    # How long to wait in seconds before re-issuing a shutdown    # signal to an instance during power off.  The overall    # time to wait is set by CONF.shutdown_timeout.    SHUTDOWN_RETRY_INTERVAL = 10    def __init__(self, compute_driver=None, *args, **kwargs):        """Load configuration options and connect to the hypervisor."""        self.scheduler_client = scheduler_client.SchedulerClient()而这里的scheduler_client原来是从nova.scheduler.clientfrom nova.scheduler import client as scheduler_client到nova.scheduler.client 这个路径下看看E:\nova\nova\scheduler\client\__init__.pyclass SchedulerClient(object):    """Client library for placing calls to the scheduler."""    def __init__(self):        self.queryclient = LazyLoader(importutils.import_class(            'nova.scheduler.client.query.SchedulerQueryClient'))        self.reportclient = LazyLoader(importutils.import_class(            'nova.scheduler.client.report.SchedulerReportClient'))    @utils.retry_select_destinations    def select_destinations(self, context, spec_obj, instance_uuids):        return self.queryclient.select_destinations(context, spec_obj,                instance_uuids)原来schedule 就提供了queryclient和reportclient 两个对外的rpc接口，这里的LazyLoader 并没有在SchedulerClient的_init__函数中加载nova.scheduler.client.query.SchedulerQueryClient和nova.scheduler.client.report.SchedulerReportClient。而是在实际使用的时候才需要，因此才叫LazyLoader这里以nova.scheduler.client.query.SchedulerQueryClient为例路径为：E:\nova\nova\scheduler\client\query.pyclass SchedulerQueryClient(object):    """Client class for querying to the scheduler."""    def __init__(self):        self.scheduler_rpcapi = scheduler_rpcapi.SchedulerAPI()    def select_destinations(self, context, spec_obj, instance_uuids):        """Returns destinations(s) best suited for this request_spec and        filter_properties.        The result should be a list of dicts with 'host', 'nodename' and        'limits' as keys.        """        return self.scheduler_rpcapi.select_destinations(context, spec_obj,                instance_uuids)原来最终还是通过scheduler_rpcapi来访问schedule的接口.可见这里的SchedulerClient真的是一个client