From bc46e647118f5d8e52f9b43fcc369823e1f65455 Mon Sep 17 00:00:00 2001
From: Kenneth Giusti <kgiusti@gmail.com>
Date: Tue, 11 Oct 2016 10:06:37 -0400
Subject: [PATCH] [AMQP 1.0] Avoid unnecessary thread switch on ack
Avoid blocking the RPC Server thread when it attempts to acknowledge
the RPC request message. Blocking is unnecessary as the acknowledge
command does not return a status and can be processed asynchronously
from the server thread.
Avoiding this context switch improves overall RPC call throughput
according to the simulator tool by approximately ten percent on my
test systems.
Change-Id: I71548eb6f9f7dcaf74cb426d4e9b369b54856419
---
oslo_messaging/_drivers/amqp1_driver/controller.py | 12 +++++++-----
oslo_messaging/_drivers/impl_amqp1.py | 6 ------
2 files changed, 7 insertions(+), 11 deletions(-)
diff --git a/oslo_messaging/_drivers/amqp1_driver/controller.py b/oslo_messaging/_drivers/amqp1_driver/controller.py
index d2d59b642..2e7ec9e18 100644
--- a/oslo_messaging/_drivers/amqp1_driver/controller.py
+++ b/oslo_messaging/_drivers/amqp1_driver/controller.py
@@ -235,17 +235,19 @@ class MessageDispositionTask(Task):
super(MessageDispositionTask, self).__init__()
self._disposition = disposition
self._released = released
- self._wakeup = threading.Event()
def wait(self):
- self._wakeup.wait()
+ # disposition update does not have to block the sender since there is
+ # no result to pend for. This avoids a thread context switch with
+ # every RPC call
+ pass
def _execute(self, controller):
try:
self._disposition(self._released)
- except Exception:
- pass
- self._wakeup.set()
+ except Exception as e:
+ # there's really nothing we can do about a failed disposition.
+ LOG.exception(_LE("Message acknowledgment failed: %s"), e)
class Sender(pyngus.SenderEventHandler):
diff --git a/oslo_messaging/_drivers/impl_amqp1.py b/oslo_messaging/_drivers/impl_amqp1.py
index 16da05fec..e48c47824 100644
--- a/oslo_messaging/_drivers/impl_amqp1.py
+++ b/oslo_messaging/_drivers/impl_amqp1.py
@@ -124,18 +124,12 @@ class ProtonIncomingMessage(base.RpcIncomingMessage):
task = controller.MessageDispositionTask(self._disposition,
released=False)
self.listener.driver._ctrl.add_task(task)
- rc = task.wait()
- if rc:
- LOG.debug("Message acknowledge failed: %s", str(rc))
def requeue(self):
"""Schedule a MessageDispositionTask to release the message"""
task = controller.MessageDispositionTask(self._disposition,
released=True)
self.listener.driver._ctrl.add_task(task)
- rc = task.wait()
- if rc:
- LOG.debug("Message requeue failed: %s", str(rc))
class Queue(object):