From 39afe0a129b6b979d0b56ec59048a4e16bedf7a9 Mon Sep 17 00:00:00 2001
From: LIU Yulong <liuyul@chinatelecom.cn>
Date: Fri, 12 Apr 2019 18:47:24 +0300
Subject: [PATCH] Do not call update_device_list in large sets

Ovs-agent can process the ports in large sets, then all
of these ports will have to update DB status or attributes.
But neutron server is centralized. It may have to do
something else, or the database processing can be also
time-consuming. Because of these, it sometimes returns
the RPC timeout exception to ovs-agent. And a fullsync
will be triggered in next rpc loop. The restart time is
becoming longer and longer.

Adds a default step to update the port to reduce
the probability of RPC timeout.

Related-Bug: #1813703
Related-Bug: #1813704
Related-Bug: #1813706
Related-Bug: #1813707

Conflicts:
	neutron/tests/unit/plugins/ml2/test_rpc.py

Change-Id: Ie37f4a4869969e235ce16b73cdfcbdc98626823e
(cherry picked from commit 8408af4f173a0ffde354599e26c49bf9e17e8bef)
(cherry picked from commit d7d30ea950844f11348fa2827908622e3a8c7dfb)
(cherry picked from commit 5d705468de1e495639f8b87266ccfc9391ce6135)
---
 neutron/agent/rpc.py                       | 29 +++++++++++++++++++---
 neutron/common/constants.py                |  3 +++
 neutron/tests/unit/plugins/ml2/test_rpc.py | 10 +++++++-
 3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/neutron/agent/rpc.py b/neutron/agent/rpc.py
index 65dd39049b3..30c63cde30e 100644
--- a/neutron/agent/rpc.py
+++ b/neutron/agent/rpc.py
@@ -147,10 +147,31 @@ class PluginApi(object):
     def update_device_list(self, context, devices_up, devices_down,
                            agent_id, host, agent_restarted=False):
         cctxt = self.client.prepare(version='1.5')
-        return cctxt.call(context, 'update_device_list',
-                          devices_up=devices_up, devices_down=devices_down,
-                          agent_id=agent_id, host=host,
-                          agent_restarted=agent_restarted)
+
+        ret_devices_up = []
+        failed_devices_up = []
+        ret_devices_down = []
+        failed_devices_down = []
+
+        step = n_const.RPC_RES_PROCESSING_STEP
+        devices_up = list(devices_up)
+        devices_down = list(devices_down)
+        for i in range(0, max(len(devices_up), len(devices_down)), step):
+            # Divide-and-conquer RPC timeout
+            ret = cctxt.call(context, 'update_device_list',
+                             devices_up=devices_up[i:i + step],
+                             devices_down=devices_down[i:i + step],
+                             agent_id=agent_id, host=host,
+                             agent_restarted=agent_restarted)
+            ret_devices_up.extend(ret.get("devices_up", []))
+            failed_devices_up.extend(ret.get("failed_devices_up", []))
+            ret_devices_down.extend(ret.get("devices_down", []))
+            failed_devices_down.extend(ret.get("failed_devices_down", []))
+
+        return {'devices_up': ret_devices_up,
+                'failed_devices_up': failed_devices_up,
+                'devices_down': ret_devices_down,
+                'failed_devices_down': failed_devices_down}
 
     def tunnel_sync(self, context, tunnel_ip, tunnel_type=None, host=None):
         cctxt = self.client.prepare(version='1.4')
diff --git a/neutron/common/constants.py b/neutron/common/constants.py
index 1b38733d643..59227559b7b 100644
--- a/neutron/common/constants.py
+++ b/neutron/common/constants.py
@@ -241,3 +241,6 @@ IEC_BASE = 1024
 # for the restart success rate.
 # [1] http://paste.openstack.org/show/745685/
 AGENT_RES_PROCESSING_STEP = 100
+# Number of resources for neutron to divide the large RPC
+# call data sets.
+RPC_RES_PROCESSING_STEP = 20
diff --git a/neutron/tests/unit/plugins/ml2/test_rpc.py b/neutron/tests/unit/plugins/ml2/test_rpc.py
index f8e9ee58901..d5ab6472117 100644
--- a/neutron/tests/unit/plugins/ml2/test_rpc.py
+++ b/neutron/tests/unit/plugins/ml2/test_rpc.py
@@ -317,9 +317,17 @@ class RpcCallbacksTestCase(base.BaseTestCase):
 class RpcApiTestCase(base.BaseTestCase):
 
     def _test_rpc_api(self, rpcapi, topic, method, rpc_method, **kwargs):
+        if method == "update_device_list":
+            expected = {'devices_up': [],
+                        'failed_devices_up': [],
+                        'devices_down': [],
+                        'failed_devices_down': []}
+        else:
+            expected = 'foo'
+
         ctxt = oslo_context.RequestContext(user='fake_user',
                                            tenant='fake_project')
-        expected_retval = 'foo' if rpc_method == 'call' else None
+        expected_retval = expected if rpc_method == 'call' else None
         expected_version = kwargs.pop('version', None)
         fanout = kwargs.pop('fanout', False)