Merge branch 'stable-2.6' into devel-2.6

[ganeti-local] / lib / rpc.py

diff --git a/lib/rpc.py b/lib/rpc.py
index cb4f4b7..b06c3c7 100644 (file)
--- a/lib/rpc.py
+++ b/lib/rpc.py
@@ -1,7 +1,7 @@
 #
 #
 
 #
 #
 

-# Copyright (C) 2006, 2007 Google Inc.
+# Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Google Inc.

 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by

@@ -23,862 +23,816 @@
 
 """
 
 
 """
 

-# pylint: disable-msg=C0103,R0201,R0904
+# pylint: disable=C0103,R0201,R0904

 # C0103: Invalid name, since call_ are not valid
 # R0201: Method could be a function, we keep all rpcs instance methods
 # as not to change them back and forth between static/instance methods
 # if they need to start using instance attributes
 # R0904: Too many public methods
 
 # C0103: Invalid name, since call_ are not valid
 # R0201: Method could be a function, we keep all rpcs instance methods
 # as not to change them back and forth between static/instance methods
 # if they need to start using instance attributes
 # R0904: Too many public methods
 

-import os
-import socket
-import httplib

 import logging
 import logging

+import zlib
+import base64
+import pycurl
+import threading

 
 from ganeti import utils
 from ganeti import objects
 from ganeti import http
 from ganeti import serializer
 from ganeti import constants
 
 from ganeti import utils
 from ganeti import objects
 from ganeti import http
 from ganeti import serializer
 from ganeti import constants

+from ganeti import errors
+from ganeti import netutils
+from ganeti import ssconf
+from ganeti import runtime
+from ganeti import compat
+from ganeti import rpc_defs

 
 

+# Special module generated at build time
+from ganeti import _generated_rpc

 
 

-# Module level variable
-_http_manager = None
+# pylint has a bug here, doesn't see this import
+import ganeti.http.client  # pylint: disable=W0611

 
 
 
 

-def Init():
-  """Initializes the module-global HTTP client manager.
+# Timeout for connecting to nodes (seconds)
+_RPC_CONNECT_TIMEOUT = 5

 
 

-  Must be called before using any RPC function.
-
-  """
-  global _http_manager
+_RPC_CLIENT_HEADERS = [
+  "Content-type: %s" % http.HTTP_APP_JSON,
+  "Expect:",
+  ]

 
 

-  assert not _http_manager, "RPC module initialized more than once"
+# Various time constants for the timeout table
+_TMO_URGENT = 60 # one minute
+_TMO_FAST = 5 * 60 # five minutes
+_TMO_NORMAL = 15 * 60 # 15 minutes
+_TMO_SLOW = 3600 # one hour
+_TMO_4HRS = 4 * 3600
+_TMO_1DAY = 86400

 
 

-  _http_manager = http.HttpClientManager()
+#: Special value to describe an offline host
+_OFFLINE = object()

 
 
 
 

-def Shutdown():
-  """Stops the module-global HTTP client manager.
+def Init():
+  """Initializes the module-global HTTP client manager.

 
 

-  Must be called before quitting the program.
+  Must be called before using any RPC function and while exactly one thread is
+  running.

 
   """
 
   """

-  global _http_manager
+  # curl_global_init(3) and curl_global_cleanup(3) must be called with only
+  # one thread running. This check is just a safety measure -- it doesn't
+  # cover all cases.
+  assert threading.activeCount() == 1, \
+         "Found more than one active thread when initializing pycURL"

 
 

-  if _http_manager:
-    _http_manager.Shutdown()
-    _http_manager = None
+  logging.info("Using PycURL %s", pycurl.version)

 
 

+  pycurl.global_init(pycurl.GLOBAL_ALL)

 
 

-class Client:
-  """RPC Client class.

 
 

-  This class, given a (remote) method name, a list of parameters and a
-  list of nodes, will contact (in parallel) all nodes, and return a
-  dict of results (key: node name, value: result).
+def Shutdown():
+  """Stops the module-global HTTP client manager.

 
 

-  One current bug is that generic failure is still signalled by
-  'False' result, which is not good. This overloading of values can
-  cause bugs.
+  Must be called before quitting the program and while exactly one thread is
+  running.

 
   """
 
   """

-  def __init__(self, procedure, args):
-    self.procedure = procedure
-    self.args = args
-    self.body = serializer.DumpJson(args, indent=False)
-
-    self.port = utils.GetNodeDaemonPort()
-    self.nc = {}
+  pycurl.global_cleanup()

 
 

-  def ConnectList(self, node_list, address_list=None):
-    """Add a list of nodes to the target nodes.

 
 

-    @type node_list: list
-    @param node_list: the list of node names to connect
-    @type address_list: list or None
-    @keyword address_list: either None or a list with node addresses,
-        which must have the same length as the node list
+def _ConfigRpcCurl(curl):
+  noded_cert = str(constants.NODED_CERT_FILE)

 
 

-    """
-    if address_list is None:
-      address_list = [None for _ in node_list]
-    else:
-      assert len(node_list) == len(address_list), \
-             "Name and address lists should have the same length"
-    for node, address in zip(node_list, address_list):
-      self.ConnectNode(node, address)
+  curl.setopt(pycurl.FOLLOWLOCATION, False)
+  curl.setopt(pycurl.CAINFO, noded_cert)
+  curl.setopt(pycurl.SSL_VERIFYHOST, 0)
+  curl.setopt(pycurl.SSL_VERIFYPEER, True)
+  curl.setopt(pycurl.SSLCERTTYPE, "PEM")
+  curl.setopt(pycurl.SSLCERT, noded_cert)
+  curl.setopt(pycurl.SSLKEYTYPE, "PEM")
+  curl.setopt(pycurl.SSLKEY, noded_cert)
+  curl.setopt(pycurl.CONNECTTIMEOUT, _RPC_CONNECT_TIMEOUT)

 
 

-  def ConnectNode(self, name, address=None):
-    """Add a node to the target list.

 
 

-    @type name: str
-    @param name: the node name
-    @type address: str
-    @keyword address: the node address, if known
+def RunWithRPC(fn):
+  """RPC-wrapper decorator.

 
 

-    """
-    if address is None:
-      address = name
-
-    # TODO: Cache key and certificate for different requests
-    ssl_params = http.HttpSslParams(ssl_key_path=constants.SSL_CERT_FILE,
-                                    ssl_cert_path=constants.SSL_CERT_FILE)
-
-    self.nc[name] = http.HttpClientRequest(address, self.port, http.HTTP_PUT,
-                                           "/%s" % self.procedure,
-                                           post_data=self.body,
-                                           ssl_params=ssl_params,
-                                           ssl_verify_peer=True)
-
-  def GetResults(self):
-    """Call nodes and return results.
-
-    @rtype: list
-    @returns: List of RPC results
-
-    """
-    assert _http_manager, "RPC module not intialized"
-
-    _http_manager.ExecRequests(self.nc.values())
-
-    results = {}
-
-    for name, req in self.nc.iteritems():
-      if req.success and req.resp_status == http.HTTP_OK:
-        results[name] = serializer.LoadJson(req.resp_body)
-        continue
-
-      if req.error:
-        msg = req.error
-      else:
-        msg = req.resp_body
+  When applied to a function, it runs it with the RPC system
+  initialized, and it shutsdown the system afterwards. This means the
+  function must be called without RPC being initialized.

 
 

-      logging.error("RPC error from node %s: %s", name, msg)
-      results[name] = False
-
-    return results
-
-
-class RpcRunner(object):
-  """RPC runner class"""
+  """
+  def wrapper(*args, **kwargs):
+    Init()
+    try:
+      return fn(*args, **kwargs)
+    finally:
+      Shutdown()
+  return wrapper

 
 

-  def __init__(self, cfg):
-    """Initialized the rpc runner.

 
 

-    @type cfg:  C{config.ConfigWriter}
-    @param cfg: the configuration object that will be used to get data
-                about the cluster
+def _Compress(data):
+  """Compresses a string for transport over RPC.

 
 

-    """
-    self._cfg = cfg
+  Small amounts of data are not compressed.

 
 

-  def _InstDict(self, instance):
-    """Convert the given instance to a dict.
-
-    This is done via the instance's ToDict() method and additionally
-    we fill the hvparams with the cluster defaults.
-
-    @type instance: L{objects.Instance}
-    @param instance: an Instance object
-    @rtype: dict
-    @return: the instance dict, with the hvparams filled with the
-        cluster defaults
+  @type data: str
+  @param data: Data
+  @rtype: tuple
+  @return: Encoded data to send

 
 

-    """
-    idict = instance.ToDict()
-    cluster = self._cfg.GetClusterInfo()
-    idict["hvparams"] = cluster.FillHV(instance)
-    idict["beparams"] = cluster.FillBE(instance)
-    return idict
+  """
+  # Small amounts of data are not compressed
+  if len(data) < 512:
+    return (constants.RPC_ENCODING_NONE, data)

 
 

-  def _ConnectList(self, client, node_list):
-    """Helper for computing node addresses.
+  # Compress with zlib and encode in base64
+  return (constants.RPC_ENCODING_ZLIB_BASE64,
+          base64.b64encode(zlib.compress(data, 3)))

 
 

-    @type client: L{Client}
-    @param client: a C{Client} instance
-    @type node_list: list
-    @param node_list: the node list we should connect

 
 

-    """
-    all_nodes = self._cfg.GetAllNodesInfo()
-    addr_list = []
-    for node in node_list:
-      if node in all_nodes:
-        val = all_nodes[node].primary_ip
-      else:
-        val = None
-      addr_list.append(val)
-    client.ConnectList(node_list, address_list=addr_list)
+class RpcResult(object):
+  """RPC Result class.

 
 

-  def _ConnectNode(self, client, node):
-    """Helper for computing one node's address.
+  This class holds an RPC result. It is needed since in multi-node
+  calls we can't raise an exception just because one one out of many
+  failed, and therefore we use this class to encapsulate the result.

 
 

-    @type client: L{Client}
-    @param client: a C{Client} instance
-    @type node: str
-    @param node: the node we should connect
+  @ivar data: the data payload, for successful results, or None
+  @ivar call: the name of the RPC call
+  @ivar node: the name of the node to which we made the call
+  @ivar offline: whether the operation failed because the node was
+      offline, as opposed to actual failure; offline=True will always
+      imply failed=True, in order to allow simpler checking if
+      the user doesn't care about the exact failure mode
+  @ivar fail_msg: the error message if the call failed

 
 

-    """
-    node_info = self._cfg.GetNodeInfo(node)
-    if node_info is not None:
-      addr = node_info.primary_ip
+  """
+  def __init__(self, data=None, failed=False, offline=False,
+               call=None, node=None):
+    self.offline = offline
+    self.call = call
+    self.node = node
+
+    if offline:
+      self.fail_msg = "Node is marked offline"
+      self.data = self.payload = None
+    elif failed:
+      self.fail_msg = self._EnsureErr(data)
+      self.data = self.payload = None

     else:
     else:

-      addr = None
-    client.ConnectNode(node, address=addr)
-
-  def _MultiNodeCall(self, node_list, procedure, args,
-                     address_list=None):
-    c = Client(procedure, args)
-    if address_list is None:
-      self._ConnectList(c, node_list)
+      self.data = data
+      if not isinstance(self.data, (tuple, list)):
+        self.fail_msg = ("RPC layer error: invalid result type (%s)" %
+                         type(self.data))
+        self.payload = None
+      elif len(data) != 2:
+        self.fail_msg = ("RPC layer error: invalid result length (%d), "
+                         "expected 2" % len(self.data))
+        self.payload = None
+      elif not self.data[0]:
+        self.fail_msg = self._EnsureErr(self.data[1])
+        self.payload = None
+      else:
+        # finally success
+        self.fail_msg = None
+        self.payload = data[1]
+
+    for attr_name in ["call", "data", "fail_msg",
+                      "node", "offline", "payload"]:
+      assert hasattr(self, attr_name), "Missing attribute %s" % attr_name
+
+  @staticmethod
+  def _EnsureErr(val):
+    """Helper to ensure we return a 'True' value for error."""
+    if val:
+      return val

     else:
     else:

-      c.ConnectList(node_list, address_list=address_list)
-    return c.GetResults()
-
-  @classmethod
-  def _StaticMultiNodeCall(cls, node_list, procedure, args,
-                           address_list=None):
-    c = Client(procedure, args)
-    c.ConnectList(node_list, address_list=address_list)
-    return c.GetResults()
-
-  def _SingleNodeCall(self, node, procedure, args):
-    """
-
-    """
-    c = Client(procedure, args)
-    self._ConnectNode(c, node)
-    return c.GetResults().get(node, False)
-
-  @classmethod
-  def _StaticSingleNodeCall(cls, node, procedure, args):
-    """
-
-    """
-    c = Client(procedure, args)
-    c.ConnectNode(c, node)
-    return c.GetResults().get(node, False)
-
-  def call_volume_list(self, node_list, vg_name):
-    """Gets the logical volumes present in a given volume group.
-
-    This is a multi-node call.
-
-    """
-    return self._MultiNodeCall(node_list, "volume_list", [vg_name])
-
-  def call_vg_list(self, node_list):
-    """Gets the volume group list.
-
-    This is a multi-node call.
-
-    """
-    return self._MultiNodeCall(node_list, "vg_list", [])
-
-  def call_bridges_exist(self, node, bridges_list):
-    """Checks if a node has all the bridges given.
-
-    This method checks if all bridges given in the bridges_list are
-    present on the remote node, so that an instance that uses interfaces
-    on those bridges can be started.
-
-    This is a single-node call.
-
-    """
-    return self._SingleNodeCall(node, "bridges_exist", [bridges_list])
-
-  def call_instance_start(self, node, instance, extra_args):
-    """Starts an instance.
-
-    This is a single-node call.
-
-    """
-    return self._SingleNodeCall(node, "instance_start",
-                                [self._InstDict(instance), extra_args])
-
-  def call_instance_shutdown(self, node, instance):
-    """Stops an instance.
-
-    This is a single-node call.
-
-    """
-    return self._SingleNodeCall(node, "instance_shutdown",
-                                [self._InstDict(instance)])
-
-  def call_instance_migrate(self, node, instance, target, live):
-    """Migrate an instance.
-
-    This is a single-node call.
-
-    @type node: string
-    @param node: the node on which the instance is currently running
-    @type instance: C{objects.Instance}
-    @param instance: the instance definition
-    @type target: string
-    @param target: the target node name
-    @type live: boolean
-    @param live: whether the migration should be done live or not (the
-        interpretation of this parameter is left to the hypervisor)
-
-    """
-    return self._SingleNodeCall(node, "instance_migrate",
-                                [self._InstDict(instance), target, live])
-
-  def call_instance_reboot(self, node, instance, reboot_type, extra_args):
-    """Reboots an instance.
-
-    This is a single-node call.
-
-    """
-    return self._SingleNodeCall(node, "instance_reboot",
-                                [self._InstDict(instance), reboot_type,
-                                 extra_args])
-
-  def call_instance_os_add(self, node, inst):
-    """Installs an OS on the given instance.
-
-    This is a single-node call.
-
-    """
-    return self._SingleNodeCall(node, "instance_os_add",
-                                [self._InstDict(inst)])
-
-  def call_instance_run_rename(self, node, inst, old_name):
-    """Run the OS rename script for an instance.
-
-    This is a single-node call.
-
-    """
-    return self._SingleNodeCall(node, "instance_run_rename",
-                                [self._InstDict(inst), old_name])
-
-  def call_instance_info(self, node, instance, hname):
-    """Returns information about a single instance.
+      return "No error information"

 
 

-    This is a single-node call.
+  def Raise(self, msg, prereq=False, ecode=None):
+    """If the result has failed, raise an OpExecError.

 
 

-    @type node: list
-    @param node: the list of nodes to query
-    @type instance: string
-    @param instance: the instance name
-    @type hname: string
-    @param hname: the hypervisor type of the instance
+    This is used so that LU code doesn't have to check for each
+    result, but instead can call this function.

 
     """
 
     """

-    return self._SingleNodeCall(node, "instance_info", [instance, hname])
+    if not self.fail_msg:
+      return

 
 

-  def call_all_instances_info(self, node_list, hypervisor_list):
-    """Returns information about all instances on the given nodes.
-
-    This is a multi-node call.
-
-    @type node_list: list
-    @param node_list: the list of nodes to query
-    @type hypervisor_list: list
-    @param hypervisor_list: the hypervisors to query for instances
-
-    """
-    return self._MultiNodeCall(node_list, "all_instances_info",
-                               [hypervisor_list])
+    if not msg: # one could pass None for default message
+      msg = ("Call '%s' to node '%s' has failed: %s" %
+             (self.call, self.node, self.fail_msg))
+    else:
+      msg = "%s: %s" % (msg, self.fail_msg)
+    if prereq:
+      ec = errors.OpPrereqError
+    else:
+      ec = errors.OpExecError
+    if ecode is not None:
+      args = (msg, ecode)
+    else:
+      args = (msg, )
+    raise ec(*args) # pylint: disable=W0142
+
+
+def _SsconfResolver(ssconf_ips, node_list, _,
+                    ssc=ssconf.SimpleStore,
+                    nslookup_fn=netutils.Hostname.GetIP):
+  """Return addresses for given node names.
+
+  @type ssconf_ips: bool
+  @param ssconf_ips: Use the ssconf IPs
+  @type node_list: list
+  @param node_list: List of node names
+  @type ssc: class
+  @param ssc: SimpleStore class that is used to obtain node->ip mappings
+  @type nslookup_fn: callable
+  @param nslookup_fn: function use to do NS lookup
+  @rtype: list of tuple; (string, string)
+  @return: List of tuples containing node name and IP address

 
 

-  def call_instance_list(self, node_list, hypervisor_list):
-    """Returns the list of running instances on a given node.
+  """
+  ss = ssc()
+  family = ss.GetPrimaryIPFamily()

 
 

-    This is a multi-node call.
+  if ssconf_ips:
+    iplist = ss.GetNodePrimaryIPList()
+    ipmap = dict(entry.split() for entry in iplist)
+  else:
+    ipmap = {}

 
 

-    @type node_list: list
-    @param node_list: the list of nodes to query
-    @type hypervisor_list: list
-    @param hypervisor_list: the hypervisors to query for instances
+  result = []
+  for node in node_list:
+    ip = ipmap.get(node)
+    if ip is None:
+      ip = nslookup_fn(node, family=family)
+    result.append((node, ip))

 
 

-    """
-    return self._MultiNodeCall(node_list, "instance_list", [hypervisor_list])
+  return result

 
 

-  def call_node_tcp_ping(self, node, source, target, port, timeout,
-                         live_port_needed):
-    """Do a TcpPing on the remote node

 
 

-    This is a single-node call.
+class _StaticResolver:
+  def __init__(self, addresses):
+    """Initializes this class.

 
     """
 
     """

-    return self._SingleNodeCall(node, "node_tcp_ping",
-                                [source, target, port, timeout,
-                                 live_port_needed])
+    self._addresses = addresses

 
 

-  def call_node_has_ip_address(self, node, address):
-    """Checks if a node has the given IP address.
-
-    This is a single-node call.
+  def __call__(self, hosts, _):
+    """Returns static addresses for hosts.

 
     """
 
     """

-    return self._SingleNodeCall(node, "node_has_ip_address", [address])
+    assert len(hosts) == len(self._addresses)
+    return zip(hosts, self._addresses)

 
 

-  def call_node_info(self, node_list, vg_name, hypervisor_type):
-    """Return node information.

 
 

-    This will return memory information and volume group size and free
-    space.
+def _CheckConfigNode(name, node, accept_offline_node):
+  """Checks if a node is online.

 
 

-    This is a multi-node call.
+  @type name: string
+  @param name: Node name
+  @type node: L{objects.Node} or None
+  @param node: Node object

 
 

-    @type node_list: list
-    @param node_list: the list of nodes to query
-    @type vgname: C{string}
-    @param vgname: the name of the volume group to ask for disk space
-        information
-    @type hypervisor_type: C{str}
-    @param hypervisor_type: the name of the hypervisor to ask for
-        memory information
+  """
+  if node is None:
+    # Depend on DNS for name resolution
+    ip = name
+  elif node.offline and not accept_offline_node:
+    ip = _OFFLINE
+  else:
+    ip = node.primary_ip
+  return (name, ip)

 
 

-    """
-    retux = self._MultiNodeCall(node_list, "node_info",
-                                [vg_name, hypervisor_type])

 
 

-    for node_name in retux:
-      ret = retux.get(node_name, False)
-      if type(ret) != dict:
-        logging.error("could not connect to node %s", node_name)
-        ret = {}
+def _NodeConfigResolver(single_node_fn, all_nodes_fn, hosts, opts):
+  """Calculate node addresses using configuration.

 
 

-      utils.CheckDict(ret, {
-                        'memory_total' : '-',
-                        'memory_dom0' : '-',
-                        'memory_free' : '-',
-                        'vg_size' : 'node_unreachable',
-                        'vg_free' : '-',
-                      }, "call_node_info")
-    return retux
+  """
+  accept_offline_node = (opts is rpc_defs.ACCEPT_OFFLINE_NODE)

 
 

-  def call_node_add(self, node, dsa, dsapub, rsa, rsapub, ssh, sshpub):
-    """Add a node to the cluster.
+  assert accept_offline_node or opts is None, "Unknown option"

 
 

-    This is a single-node call.
+  # Special case for single-host lookups
+  if len(hosts) == 1:
+    (name, ) = hosts
+    return [_CheckConfigNode(name, single_node_fn(name), accept_offline_node)]
+  else:
+    all_nodes = all_nodes_fn()
+    return [_CheckConfigNode(name, all_nodes.get(name, None),
+                             accept_offline_node)
+            for name in hosts]

 
 

-    """
-    return self._SingleNodeCall(node, "node_add",
-                                [dsa, dsapub, rsa, rsapub, ssh, sshpub])

 
 

-  def call_node_verify(self, node_list, checkdict, cluster_name):
-    """Request verification of given parameters.
+class _RpcProcessor:
+  def __init__(self, resolver, port, lock_monitor_cb=None):
+    """Initializes this class.

 
 

-    This is a multi-node call.
+    @param resolver: callable accepting a list of hostnames, returning a list
+      of tuples containing name and IP address (IP address can be the name or
+      the special value L{_OFFLINE} to mark offline machines)
+    @type port: int
+    @param port: TCP port
+    @param lock_monitor_cb: Callable for registering with lock monitor

 
     """
 
     """

-    return self._MultiNodeCall(node_list, "node_verify",
-                               [checkdict, cluster_name])
+    self._resolver = resolver
+    self._port = port
+    self._lock_monitor_cb = lock_monitor_cb

 
 

-  @classmethod
-  def call_node_start_master(cls, node, start_daemons):
-    """Tells a node to activate itself as a master.
+  @staticmethod
+  def _PrepareRequests(hosts, port, procedure, body, read_timeout):
+    """Prepares requests by sorting offline hosts into separate list.

 
 

-    This is a single-node call.
+    @type body: dict
+    @param body: a dictionary with per-host body data

 
     """
 
     """

-    return cls._StaticSingleNodeCall(node, "node_start_master",
-                                     [start_daemons])
+    results = {}
+    requests = {}
+
+    assert isinstance(body, dict)
+    assert len(body) == len(hosts)
+    assert compat.all(isinstance(v, str) for v in body.values())
+    assert frozenset(map(compat.fst, hosts)) == frozenset(body.keys()), \
+        "%s != %s" % (hosts, body.keys())
+
+    for (name, ip) in hosts:
+      if ip is _OFFLINE:
+        # Node is marked as offline
+        results[name] = RpcResult(node=name, offline=True, call=procedure)
+      else:
+        requests[name] = \
+          http.client.HttpClientRequest(str(ip), port,
+                                        http.HTTP_POST, str("/%s" % procedure),
+                                        headers=_RPC_CLIENT_HEADERS,
+                                        post_data=body[name],
+                                        read_timeout=read_timeout,
+                                        nicename="%s/%s" % (name, procedure),
+                                        curl_config_fn=_ConfigRpcCurl)
+
+    return (results, requests)
+
+  @staticmethod
+  def _CombineResults(results, requests, procedure):
+    """Combines pre-computed results for offline hosts with actual call results.
+
+    """
+    for name, req in requests.items():
+      if req.success and req.resp_status_code == http.HTTP_OK:
+        host_result = RpcResult(data=serializer.LoadJson(req.resp_body),
+                                node=name, call=procedure)
+      else:
+        # TODO: Better error reporting
+        if req.error:
+          msg = req.error
+        else:
+          msg = req.resp_body

 
 

-  @classmethod
-  def call_node_stop_master(cls, node, stop_daemons):
-    """Tells a node to demote itself from master status.
+        logging.error("RPC error in %s on node %s: %s", procedure, name, msg)
+        host_result = RpcResult(data=msg, failed=True, node=name,
+                                call=procedure)

 
 

-    This is a single-node call.
+      results[name] = host_result

 
 

-    """
-    return cls._StaticSingleNodeCall(node, "node_stop_master", [stop_daemons])
+    return results

 
 

-  @classmethod
-  def call_master_info(cls, node_list):
-    """Query master info.
+  def __call__(self, hosts, procedure, body, read_timeout, resolver_opts,
+               _req_process_fn=None):
+    """Makes an RPC request to a number of nodes.

 
 

-    This is a multi-node call.
+    @type hosts: sequence
+    @param hosts: Hostnames
+    @type procedure: string
+    @param procedure: Request path
+    @type body: dictionary
+    @param body: dictionary with request bodies per host
+    @type read_timeout: int or None
+    @param read_timeout: Read timeout for request

 
     """
 
     """

-    # TODO: should this method query down nodes?
-    return cls._StaticMultiNodeCall(node_list, "master_info", [])
+    assert read_timeout is not None, \
+      "Missing RPC read timeout for procedure '%s'" % procedure

 
 

-  def call_version(self, node_list):
-    """Query node version.
+    if _req_process_fn is None:
+      _req_process_fn = http.client.ProcessRequests

 
 

-    This is a multi-node call.
+    (results, requests) = \
+      self._PrepareRequests(self._resolver(hosts, resolver_opts), self._port,
+                            procedure, body, read_timeout)

 
 

-    """
-    return self._MultiNodeCall(node_list, "version", [])
+    _req_process_fn(requests.values(), lock_monitor_cb=self._lock_monitor_cb)

 
 

-  def call_blockdev_create(self, node, bdev, size, owner, on_primary, info):
-    """Request creation of a given block device.
+    assert not frozenset(results).intersection(requests)

 
 

-    This is a single-node call.
+    return self._CombineResults(results, requests, procedure)

 
 

-    """
-    return self._SingleNodeCall(node, "blockdev_create",
-                                [bdev.ToDict(), size, owner, on_primary, info])

 
 

-  def call_blockdev_remove(self, node, bdev):
-    """Request removal of a given block device.
-
-    This is a single-node call.
+class _RpcClientBase:
+  def __init__(self, resolver, encoder_fn, lock_monitor_cb=None,
+               _req_process_fn=None):
+    """Initializes this class.

 
     """
 
     """

-    return self._SingleNodeCall(node, "blockdev_remove", [bdev.ToDict()])
-
-  def call_blockdev_rename(self, node, devlist):
-    """Request rename of the given block devices.
+    proc = _RpcProcessor(resolver,
+                         netutils.GetDaemonPort(constants.NODED),
+                         lock_monitor_cb=lock_monitor_cb)
+    self._proc = compat.partial(proc, _req_process_fn=_req_process_fn)
+    self._encoder = compat.partial(self._EncodeArg, encoder_fn)

 
 

-    This is a single-node call.
+  @staticmethod
+  def _EncodeArg(encoder_fn, (argkind, value)):
+    """Encode argument.

 
     """
 
     """

-    return self._SingleNodeCall(node, "blockdev_rename",
-                                [(d.ToDict(), uid) for d, uid in devlist])
-
-  def call_blockdev_assemble(self, node, disk, owner, on_primary):
-    """Request assembling of a given block device.
+    if argkind is None:
+      return value
+    else:
+      return encoder_fn(argkind)(value)

 
 

-    This is a single-node call.
+  def _Call(self, cdef, node_list, args):
+    """Entry point for automatically generated RPC wrappers.

 
     """
 
     """

-    return self._SingleNodeCall(node, "blockdev_assemble",
-                                [disk.ToDict(), owner, on_primary])
-
-  def call_blockdev_shutdown(self, node, disk):
-    """Request shutdown of a given block device.
+    (procedure, _, resolver_opts, timeout, argdefs,
+     prep_fn, postproc_fn, _) = cdef

 
 

-    This is a single-node call.
+    if callable(timeout):
+      read_timeout = timeout(args)
+    else:
+      read_timeout = timeout

 
 

-    """
-    return self._SingleNodeCall(node, "blockdev_shutdown", [disk.ToDict()])
+    if callable(resolver_opts):
+      req_resolver_opts = resolver_opts(args)
+    else:
+      req_resolver_opts = resolver_opts

 
 

-  def call_blockdev_addchildren(self, node, bdev, ndevs):
-    """Request adding a list of children to a (mirroring) device.
+    if len(args) != len(argdefs):
+      raise errors.ProgrammerError("Number of passed arguments doesn't match")

 
 

-    This is a single-node call.
+    enc_args = map(self._encoder, zip(map(compat.snd, argdefs), args))
+    if prep_fn is None:
+      # for a no-op prep_fn, we serialise the body once, and then we
+      # reuse it in the dictionary values
+      body = serializer.DumpJson(enc_args)
+      pnbody = dict((n, body) for n in node_list)
+    else:
+      # for a custom prep_fn, we pass the encoded arguments and the
+      # node name to the prep_fn, and we serialise its return value
+      assert callable(prep_fn)
+      pnbody = dict((n, serializer.DumpJson(prep_fn(n, enc_args)))
+                    for n in node_list)
+
+    result = self._proc(node_list, procedure, pnbody, read_timeout,
+                        req_resolver_opts)
+
+    if postproc_fn:
+      return dict(map(lambda (key, value): (key, postproc_fn(value)),
+                      result.items()))
+    else:
+      return result

 
 

-    """
-    return self._SingleNodeCall(node, "blockdev_addchildren",
-                                [bdev.ToDict(),
-                                 [disk.ToDict() for disk in ndevs]])

 
 

-  def call_blockdev_removechildren(self, node, bdev, ndevs):
-    """Request removing a list of children from a (mirroring) device.
+def _ObjectToDict(value):
+  """Converts an object to a dictionary.

 
 

-    This is a single-node call.
+  @note: See L{objects}.

 
 

-    """
-    return self._SingleNodeCall(node, "blockdev_removechildren",
-                                [bdev.ToDict(),
-                                 [disk.ToDict() for disk in ndevs]])
+  """
+  return value.ToDict()

 
 

-  def call_blockdev_getmirrorstatus(self, node, disks):
-    """Request status of a (mirroring) device.

 
 

-    This is a single-node call.
+def _ObjectListToDict(value):
+  """Converts a list of L{objects} to dictionaries.

 
 

-    """
-    return self._SingleNodeCall(node, "blockdev_getmirrorstatus",
-                                [dsk.ToDict() for dsk in disks])
+  """
+  return map(_ObjectToDict, value)

 
 

-  def call_blockdev_find(self, node, disk):
-    """Request identification of a given block device.

 
 

-    This is a single-node call.
+def _EncodeNodeToDiskDict(value):
+  """Encodes a dictionary with node name as key and disk objects as values.

 
 

-    """
-    return self._SingleNodeCall(node, "blockdev_find", [disk.ToDict()])
+  """
+  return dict((name, _ObjectListToDict(disks))
+              for name, disks in value.items())

 
 

-  def call_blockdev_close(self, node, disks):
-    """Closes the given block devices.

 
 

-    This is a single-node call.
+def _PrepareFileUpload(getents_fn, filename):
+  """Loads a file and prepares it for an upload to nodes.

 
 

-    """
-    return self._SingleNodeCall(node, "blockdev_close",
-                                [cf.ToDict() for cf in disks])
+  """
+  statcb = utils.FileStatHelper()
+  data = _Compress(utils.ReadFile(filename, preread=statcb))
+  st = statcb.st

 
 

-  @classmethod
-  def call_upload_file(cls, node_list, file_name, address_list=None):
-    """Upload a file.
+  if getents_fn is None:
+    getents_fn = runtime.GetEnts

 
 

-    The node will refuse the operation in case the file is not on the
-    approved file list.
+  getents = getents_fn()

 
 

-    This is a multi-node call.
+  return [filename, data, st.st_mode, getents.LookupUid(st.st_uid),
+          getents.LookupGid(st.st_gid), st.st_atime, st.st_mtime]

 
 

-    @type node_list: list
-    @param node_list: the list of node names to upload to
-    @type file_name: str
-    @param file_name: the filename to upload
-    @type address_list: list or None
-    @keyword address_list: an optional list of node addresses, in order
-        to optimize the RPC speed

 
 

-    """
-    data = utils.ReadFile(file_name)
-    st = os.stat(file_name)
-    params = [file_name, data, st.st_mode, st.st_uid, st.st_gid,
-              st.st_atime, st.st_mtime]
-    return cls._StaticMultiNodeCall(node_list, "upload_file", params,
-                                    address_list=address_list)
+def _PrepareFinalizeExportDisks(snap_disks):
+  """Encodes disks for finalizing export.

 
 

-  @classmethod
-  def call_write_ssconf_files(cls, node_list):
-    """Write ssconf files.
+  """
+  flat_disks = []

 
 

-    This is a multi-node call.
+  for disk in snap_disks:
+    if isinstance(disk, bool):
+      flat_disks.append(disk)
+    else:
+      flat_disks.append(disk.ToDict())

 
 

-    """
-    return cls._StaticMultiNodeCall(node_list, "write_ssconf_files", [])
+  return flat_disks

 
 

-  def call_os_diagnose(self, node_list):
-    """Request a diagnose of OS definitions.

 
 

-    This is a multi-node call.
+def _EncodeImportExportIO((ieio, ieioargs)):
+  """Encodes import/export I/O information.

 
 

-    """
-    result = self._MultiNodeCall(node_list, "os_diagnose", [])
+  """
+  if ieio == constants.IEIO_RAW_DISK:
+    assert len(ieioargs) == 1
+    return (ieio, (ieioargs[0].ToDict(), ))

 
 

-    new_result = {}
-    for node_name in result:
-      if result[node_name]:
-        nr = [objects.OS.FromDict(oss) for oss in result[node_name]]
-      else:
-        nr = []
-      new_result[node_name] = nr
-    return new_result
+  if ieio == constants.IEIO_SCRIPT:
+    assert len(ieioargs) == 2
+    return (ieio, (ieioargs[0].ToDict(), ieioargs[1]))

 
 

-  def call_os_get(self, node, name):
-    """Returns an OS definition.
+  return (ieio, ieioargs)

 
 

-    This is a single-node call.

 
 

-    """
-    result = self._SingleNodeCall(node, "os_get", [name])
-    if isinstance(result, dict):
-      return objects.OS.FromDict(result)
-    else:
-      return result
+def _EncodeBlockdevRename(value):
+  """Encodes information for renaming block devices.

 
 

-  def call_hooks_runner(self, node_list, hpath, phase, env):
-    """Call the hooks runner.
+  """
+  return [(d.ToDict(), uid) for d, uid in value]

 
 

-    Args:
-      - op: the OpCode instance
-      - env: a dictionary with the environment

 
 

-    This is a multi-node call.
+def _AnnotateDParamsDRBD(disk, (drbd_params, data_params, meta_params)):
+  """Annotates just DRBD disks layouts.

 
 

-    """
-    params = [hpath, phase, env]
-    return self._MultiNodeCall(node_list, "hooks_runner", params)
+  """
+  assert disk.dev_type == constants.LD_DRBD8

 
 

-  def call_iallocator_runner(self, node, name, idata):
-    """Call an iallocator on a remote node
+  disk.params = objects.FillDict(drbd_params, disk.params)
+  (dev_data, dev_meta) = disk.children
+  dev_data.params = objects.FillDict(data_params, dev_data.params)
+  dev_meta.params = objects.FillDict(meta_params, dev_meta.params)

 
 

-    Args:
-      - name: the iallocator name
-      - input: the json-encoded input string
+  return disk

 
 

-    This is a single-node call.

 
 

-    """
-    return self._SingleNodeCall(node, "iallocator_runner", [name, idata])
+def _AnnotateDParamsGeneric(disk, (params, )):
+  """Generic disk parameter annotation routine.

 
 

-  def call_blockdev_grow(self, node, cf_bdev, amount):
-    """Request a snapshot of the given block device.
+  """
+  assert disk.dev_type != constants.LD_DRBD8

 
 

-    This is a single-node call.
+  disk.params = objects.FillDict(params, disk.params)

 
 

-    """
-    return self._SingleNodeCall(node, "blockdev_grow",
-                                [cf_bdev.ToDict(), amount])
+  return disk

 
 

-  def call_blockdev_snapshot(self, node, cf_bdev):
-    """Request a snapshot of the given block device.

 
 

-    This is a single-node call.
+def AnnotateDiskParams(template, disks, disk_params):
+  """Annotates the disk objects with the disk parameters.

 
 

-    """
-    return self._SingleNodeCall(node, "blockdev_snapshot", [cf_bdev.ToDict()])
+  @param template: The disk template used
+  @param disks: The list of disks objects to annotate
+  @param disk_params: The disk paramaters for annotation
+  @returns: A list of disk objects annotated

 
 

-  def call_snapshot_export(self, node, snap_bdev, dest_node, instance,
-                           cluster_name, idx):
-    """Request the export of a given snapshot.
+  """
+  ld_params = objects.Disk.ComputeLDParams(template, disk_params)

 
 

-    This is a single-node call.
+  if template == constants.DT_DRBD8:
+    annotation_fn = _AnnotateDParamsDRBD
+  elif template == constants.DT_DISKLESS:
+    annotation_fn = lambda disk, _: disk
+  else:
+    annotation_fn = _AnnotateDParamsGeneric

 
 

-    """
-    return self._SingleNodeCall(node, "snapshot_export",
-                                [snap_bdev.ToDict(), dest_node,
-                                 self._InstDict(instance), cluster_name, idx])
+  new_disks = []
+  for disk in disks:
+    new_disks.append(annotation_fn(disk.Copy(), ld_params))

 
 

-  def call_finalize_export(self, node, instance, snap_disks):
-    """Request the completion of an export operation.
+  return new_disks

 
 

-    This writes the export config file, etc.

 
 

-    This is a single-node call.
+#: Generic encoders
+_ENCODERS = {
+  rpc_defs.ED_OBJECT_DICT: _ObjectToDict,
+  rpc_defs.ED_OBJECT_DICT_LIST: _ObjectListToDict,
+  rpc_defs.ED_NODE_TO_DISK_DICT: _EncodeNodeToDiskDict,
+  rpc_defs.ED_COMPRESS: _Compress,
+  rpc_defs.ED_FINALIZE_EXPORT_DISKS: _PrepareFinalizeExportDisks,
+  rpc_defs.ED_IMPEXP_IO: _EncodeImportExportIO,
+  rpc_defs.ED_BLOCKDEV_RENAME: _EncodeBlockdevRename,
+  }

 
 

-    """
-    flat_disks = []
-    for disk in snap_disks:
-      flat_disks.append(disk.ToDict())

 
 

-    return self._SingleNodeCall(node, "finalize_export",
-                                [self._InstDict(instance), flat_disks])
+class RpcRunner(_RpcClientBase,
+                _generated_rpc.RpcClientDefault,
+                _generated_rpc.RpcClientBootstrap,
+                _generated_rpc.RpcClientDnsOnly,
+                _generated_rpc.RpcClientConfig):
+  """RPC runner class.

 
 

-  def call_export_info(self, node, path):
-    """Queries the export information in a given path.
+  """
+  def __init__(self, cfg, lock_monitor_cb, _req_process_fn=None, _getents=None):
+    """Initialized the RPC runner.

 
 

-    This is a single-node call.
+    @type cfg: L{config.ConfigWriter}
+    @param cfg: Configuration
+    @type lock_monitor_cb: callable
+    @param lock_monitor_cb: Lock monitor callback

 
     """
 
     """

-    result = self._SingleNodeCall(node, "export_info", [path])
-    if not result:
-      return result
-    return objects.SerializableConfigParser.Loads(str(result))
-
-  def call_instance_os_import(self, node, inst, src_node, src_images,
-                              cluster_name):
-    """Request the import of a backup into an instance.
-
-    This is a single-node call.
+    self._cfg = cfg

 
 

-    """
-    return self._SingleNodeCall(node, "instance_os_import",
-                                [self._InstDict(inst), src_node, src_images,
-                                 cluster_name])
+    encoders = _ENCODERS.copy()
+
+    encoders.update({
+      # Encoders requiring configuration object
+      rpc_defs.ED_INST_DICT: self._InstDict,
+      rpc_defs.ED_INST_DICT_HVP_BEP_DP: self._InstDictHvpBepDp,
+      rpc_defs.ED_INST_DICT_OSP_DP: self._InstDictOspDp,
+
+      # Encoders annotating disk parameters
+      rpc_defs.ED_DISKS_DICT_DP: self._DisksDictDP,
+      rpc_defs.ED_SINGLE_DISK_DICT_DP: self._SingleDiskDictDP,
+
+      # Encoders with special requirements
+      rpc_defs.ED_FILE_DETAILS: compat.partial(_PrepareFileUpload, _getents),
+      })
+
+    # Resolver using configuration
+    resolver = compat.partial(_NodeConfigResolver, cfg.GetNodeInfo,
+                              cfg.GetAllNodesInfo)
+
+    # Pylint doesn't recognize multiple inheritance properly, see
+    # <http://www.logilab.org/ticket/36586> and
+    # <http://www.logilab.org/ticket/35642>
+    # pylint: disable=W0233
+    _RpcClientBase.__init__(self, resolver, encoders.get,
+                            lock_monitor_cb=lock_monitor_cb,
+                            _req_process_fn=_req_process_fn)
+    _generated_rpc.RpcClientConfig.__init__(self)
+    _generated_rpc.RpcClientBootstrap.__init__(self)
+    _generated_rpc.RpcClientDnsOnly.__init__(self)
+    _generated_rpc.RpcClientDefault.__init__(self)
+
+  def _InstDict(self, instance, hvp=None, bep=None, osp=None):
+    """Convert the given instance to a dict.

 
 

-  def call_export_list(self, node_list):
-    """Gets the stored exports list.
+    This is done via the instance's ToDict() method and additionally
+    we fill the hvparams with the cluster defaults.

 
 

-    This is a multi-node call.
+    @type instance: L{objects.Instance}
+    @param instance: an Instance object
+    @type hvp: dict or None
+    @param hvp: a dictionary with overridden hypervisor parameters
+    @type bep: dict or None
+    @param bep: a dictionary with overridden backend parameters
+    @type osp: dict or None
+    @param osp: a dictionary with overridden os parameters
+    @rtype: dict
+    @return: the instance dict, with the hvparams filled with the
+        cluster defaults

 
     """
 
     """

-    return self._MultiNodeCall(node_list, "export_list", [])
-
-  def call_export_remove(self, node, export):
-    """Requests removal of a given export.
+    idict = instance.ToDict()
+    cluster = self._cfg.GetClusterInfo()
+    idict["hvparams"] = cluster.FillHV(instance)
+    if hvp is not None:
+      idict["hvparams"].update(hvp)
+    idict["beparams"] = cluster.FillBE(instance)
+    if bep is not None:
+      idict["beparams"].update(bep)
+    idict["osparams"] = cluster.SimpleFillOS(instance.os, instance.osparams)
+    if osp is not None:
+      idict["osparams"].update(osp)
+    for nic in idict["nics"]:
+      nic["nicparams"] = objects.FillDict(
+        cluster.nicparams[constants.PP_DEFAULT],
+        nic["nicparams"])
+    idict["disks"] = self._DisksDictDP((instance.disks, instance))
+    return idict

 
 

-    This is a single-node call.
+  def _InstDictHvpBepDp(self, (instance, hvp, bep)):
+    """Wrapper for L{_InstDict}.

 
     """
 
     """

-    return self._SingleNodeCall(node, "export_remove", [export])
-
-  @classmethod
-  def call_node_leave_cluster(cls, node):
-    """Requests a node to clean the cluster information it has.
+    return self._InstDict(instance, hvp=hvp, bep=bep)

 
 

-    This will remove the configuration information from the ganeti data
-    dir.
-
-    This is a single-node call.
+  def _InstDictOspDp(self, (instance, osparams)):
+    """Wrapper for L{_InstDict}.

 
     """
 
     """

-    return cls._StaticSingleNodeCall(node, "node_leave_cluster", [])
-
-  def call_node_volumes(self, node_list):
-    """Gets all volumes on node(s).
+    return self._InstDict(instance, osp=osparams)

 
 

-    This is a multi-node call.
+  def _DisksDictDP(self, (disks, instance)):
+    """Wrapper for L{AnnotateDiskParams}.

 
     """
 
     """

-    return self._MultiNodeCall(node_list, "node_volumes", [])
-
-  def call_test_delay(self, node_list, duration):
-    """Sleep for a fixed time on given node(s).
+    diskparams = self._cfg.GetInstanceDiskParams(instance)
+    return [disk.ToDict()
+            for disk in AnnotateDiskParams(instance.disk_template,
+                                           disks, diskparams)]

 
 

-    This is a multi-node call.
+  def _SingleDiskDictDP(self, (disk, instance)):
+    """Wrapper for L{AnnotateDiskParams}.

 
     """
 
     """

-    return self._MultiNodeCall(node_list, "test_delay", [duration])
+    (anno_disk,) = self._DisksDictDP(([disk], instance))
+    return anno_disk

 
 

-  def call_file_storage_dir_create(self, node, file_storage_dir):
-    """Create the given file storage directory.

 
 

-    This is a single-node call.
+class JobQueueRunner(_RpcClientBase, _generated_rpc.RpcClientJobQueue):
+  """RPC wrappers for job queue.

 
 

-    """
-    return self._SingleNodeCall(node, "file_storage_dir_create",
-                                [file_storage_dir])
-
-  def call_file_storage_dir_remove(self, node, file_storage_dir):
-    """Remove the given file storage directory.
-
-    This is a single-node call.
+  """
+  def __init__(self, context, address_list):
+    """Initializes this class.

 
     """
 
     """

-    return self._SingleNodeCall(node, "file_storage_dir_remove",
-                                [file_storage_dir])
-
-  def call_file_storage_dir_rename(self, node, old_file_storage_dir,
-                                   new_file_storage_dir):
-    """Rename file storage directory.
+    if address_list is None:
+      resolver = compat.partial(_SsconfResolver, True)
+    else:
+      # Caller provided an address list
+      resolver = _StaticResolver(address_list)

 
 

-    This is a single-node call.
+    _RpcClientBase.__init__(self, resolver, _ENCODERS.get,
+                            lock_monitor_cb=context.glm.AddToLockMonitor)
+    _generated_rpc.RpcClientJobQueue.__init__(self)

 
 

-    """
-    return self._SingleNodeCall(node, "file_storage_dir_rename",
-                                [old_file_storage_dir, new_file_storage_dir])

 
 

-  @classmethod
-  def call_jobqueue_update(cls, node_list, address_list, file_name, content):
-    """Update job queue.
+class BootstrapRunner(_RpcClientBase,
+                      _generated_rpc.RpcClientBootstrap,
+                      _generated_rpc.RpcClientDnsOnly):
+  """RPC wrappers for bootstrapping.

 
 

-    This is a multi-node call.
+  """
+  def __init__(self):
+    """Initializes this class.

 
     """
 
     """

-    return cls._StaticMultiNodeCall(node_list, "jobqueue_update",
-                                    [file_name, content],
-                                    address_list=address_list)
+    # Pylint doesn't recognize multiple inheritance properly, see
+    # <http://www.logilab.org/ticket/36586> and
+    # <http://www.logilab.org/ticket/35642>
+    # pylint: disable=W0233
+    _RpcClientBase.__init__(self, compat.partial(_SsconfResolver, True),
+                            _ENCODERS.get)
+    _generated_rpc.RpcClientBootstrap.__init__(self)
+    _generated_rpc.RpcClientDnsOnly.__init__(self)

 
 

-  @classmethod
-  def call_jobqueue_purge(cls, node):
-    """Purge job queue.

 
 

-    This is a single-node call.
+class DnsOnlyRunner(_RpcClientBase, _generated_rpc.RpcClientDnsOnly):
+  """RPC wrappers for calls using only DNS.

 
 

-    """
-    return cls._StaticSingleNodeCall(node, "jobqueue_purge", [])
-
-  @classmethod
-  def call_jobqueue_rename(cls, node_list, address_list, old, new):
-    """Rename a job queue file.
-
-    This is a multi-node call.
+  """
+  def __init__(self):
+    """Initialize this class.

 
     """
 
     """

-    return cls._StaticMultiNodeCall(node_list, "jobqueue_rename", [old, new],
-                                    address_list=address_list)
+    _RpcClientBase.__init__(self, compat.partial(_SsconfResolver, False),
+                            _ENCODERS.get)
+    _generated_rpc.RpcClientDnsOnly.__init__(self)

 
 

-  @classmethod
-  def call_jobqueue_set_drain(cls, node_list, drain_flag):
-    """Set the drain flag on the queue.

 
 

-    This is a multi-node call.
+class ConfigRunner(_RpcClientBase, _generated_rpc.RpcClientConfig):
+  """RPC wrappers for L{config}.

 
 

-    @type node_list: list
-    @param node_list: the list of nodes to query
-    @type drain_flag: bool
-    @param drain_flag: if True, will set the drain flag, otherwise reset it.
+  """
+  def __init__(self, context, address_list, _req_process_fn=None,
+               _getents=None):
+    """Initializes this class.

 
     """
 
     """

-    return cls._StaticMultiNodeCall(node_list, "jobqueue_set_drain",
-                                    [drain_flag])
+    if context:
+      lock_monitor_cb = context.glm.AddToLockMonitor
+    else:
+      lock_monitor_cb = None

 
 

-  def call_hypervisor_validate_params(self, node_list, hvname, hvparams):
-    """Validate the hypervisor params.
+    if address_list is None:
+      resolver = compat.partial(_SsconfResolver, True)
+    else:
+      # Caller provided an address list
+      resolver = _StaticResolver(address_list)

 
 

-    This is a multi-node call.
+    encoders = _ENCODERS.copy()

 
 

-    @type node_list: list
-    @param node_list: the list of nodes to query
-    @type hvname: string
-    @param hvname: the hypervisor name
-    @type hvparams: dict
-    @param hvparams: the hypervisor parameters to be validated
+    encoders.update({
+      rpc_defs.ED_FILE_DETAILS: compat.partial(_PrepareFileUpload, _getents),
+      })

 
 

-    """
-    cluster = self._cfg.GetClusterInfo()
-    hv_full = cluster.FillDict(cluster.hvparams.get(hvname, {}), hvparams)
-    return self._MultiNodeCall(node_list, "hypervisor_validate_params",
-                               [hvname, hv_full])
+    _RpcClientBase.__init__(self, resolver, encoders.get,
+                            lock_monitor_cb=lock_monitor_cb,
+                            _req_process_fn=_req_process_fn)
+    _generated_rpc.RpcClientConfig.__init__(self)