openstack/swift
Code Issues Proposed changes

Use TCP_NODELAY on outgoing connections

Browse Source 
On a loopback device (e.g., when proxy-server and object-server are on
same node), PUTs in the range 64-200K may experience a delay due to the
effect of Nagel interacting with the loopback MTU of 64K.

This effect has been directly seen by Mark Seger and Rick Jones on a
proxy-server to object-server PUT. However, you could expect to see a
similar effect on replication via ssync if the object being replicated
is on a different drive on the same node.

A prior change [1] related to Nagel set TCP_NODELAY on responses. This change
sets it on all outgoing connections.

[1] I11f86df1f56fba1c6ab6084dc1f580c395f072dc

Change-Id: Ife8885a42b289a5eb4ac7e4698f8889858bc8b7e
Closes-bug: 1408622
This commit is contained in:
Donagh McCabe 2015-01-08 14:52:32 +00:00 committed by Alistair Coles
parent fee3dcf1f1
commit b434be452e
2 changed files with 8 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
swift/common/bufferedhttp.py
View File

@ -30,6 +30,7 @@ from swift import gettext_ as _
from urllib import quote from urllib import quote
import logging import logging
import time import time
import socket
from eventlet.green.httplib import CONTINUE, HTTPConnection, HTTPMessage, \ from eventlet.green.httplib import CONTINUE, HTTPConnection, HTTPMessage, \
HTTPResponse, HTTPSConnection, _UNKNOWN HTTPResponse, HTTPSConnection, _UNKNOWN
@ -105,7 +106,9 @@ class BufferedHTTPConnection(HTTPConnection):
def connect(self): def connect(self):
self._connected_time = time.time() self._connected_time = time.time()
return HTTPConnection.connect(self) ret = HTTPConnection.connect(self)
self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
return ret
def putrequest(self, method, url, skip_host=0, skip_accept_encoding=0): def putrequest(self, method, url, skip_host=0, skip_accept_encoding=0):
self._method = method self._method = method

4
test/unit/common/test_bufferedhttp.py
View File

@ -15,6 +15,8 @@
import unittest import unittest
import socket
from eventlet import spawn, Timeout, listen from eventlet import spawn, Timeout, listen
from swift.common import bufferedhttp from swift.common import bufferedhttp
@ -60,6 +62,8 @@ class TestBufferedHTTP(unittest.TestCase):
'x-header': 'value'}, 'x-header': 'value'},
query_string='omg&no=%7f') query_string='omg&no=%7f')
conn.send('REQUEST\r\n') conn.send('REQUEST\r\n')
self.assertTrue(conn.sock.getsockopt(socket.IPPROTO_TCP,
socket.TCP_NODELAY))
resp = conn.getresponse() resp = conn.getresponse()
body = resp.read() body = resp.read()
conn.close() conn.close()