Classification: Public
Hi,
I am using the ThreadSafeClientConnectionManager in the HttpClient 4.1 API to
submit secure requests to a webserver (nginx). From the debug logs, I do see
that the connections are being pooled and reused, however, if I use netstat or
tcpview I see that new TCP connections are constantly being created in the
ESTABLISHED state and the old ones are put in TIME_WAIT state with no further
activity. What I would expect to see is that the same TCP handle would be
reused for a period of time. Can someone explain to me why a KeepAlive
connection kicked off by HttpClient would not be reused? I can confirm that the
web server supports keep alive and that the server is reporting that my program
is closing the keep-alive connections
Please see a sample of my DEBUG logs below:
DEBUG 03:07:03.490 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.t.ConnPoolByRoute - [HttpRoute[{s https://xxxx.intranet.com:410]]
total kept alive: 10, total issued: 0, total allocated: 10 out of 10
DEBUG 03:07:03.490 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.DefaultClientConnection - Connection closed
DEBUG 03:07:03.490 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.t.ConnPoolByRoute - Getting free connection
[HttpRoute[{s}->https://xxxx.intranet.com:410]][null]
DEBUG 03:07:03.490 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.DefaultClientConnectionOperator - Connecting to
://xxxx.intranet.com:410
DEBUG 03:07:03.549 - 08/09/2011 [pool-1-thread-43] []
o.a.h.c.p.RequestAddCookies - CookieSpec selected: best-match
DEBUG 03:07:03.549 - 08/09/2011 [pool-1-thread-43] []
o.a.h.c.p.RequestAuthCache - Auth cache not set in the context
DEBUG 03:07:03.549 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.DefaultHttpClient - Attempt 1 to execute request
DEBUG 03:07:03.549 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.DefaultClientConnection - Sending request: PUT
/bla/put?name=TG_AUD_3M HTTP/1.1
DEBUG 03:07:03.552 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.DefaultClientConnection - Receiving response: HTTP/1.1 201 Created
DEBUG 03:07:03.552 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.DefaultHttpClient - Connection can be kept alive for 60000
MILLISECONDS
DEBUG 03:07:03.552 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.t.ThreadSafeClientConnManager - Released connection is reusable.
DEBUG 03:07:03.552 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.t.ConnPoolByRoute - Releasing connection [HttpRoute[{s}->https://
xxxx.intranet.com:410]][CN=xxxxx.uk.db.com:Tesla, O=xxxx, DC=xx, DC=com]
DEBUG 03:07:03.552 - 08/09/2011 [pool-1-thread-43] []
o.a.h.i.c.t.ConnPoolByRoute - Pooling connection [[HttpRoute[{s}->https://
xxxx.intranet.com:410]][CN=xxxxx.uk.db.com:Tesla, O=xxxx, DC=xx, DC=com];keep
alive for 60000 MILLISECONDS
I have a PUT request twice every second and I see that on average 2 TCP
connections are established on the server every second, with the previous 2
being put in TIME_WAIT state.
The Response received from the server is as follows:
Response headers:
HTTP/1.1 201 Created
Server: nginx/1.0.4
Date: Thu, 08 Sep 2011 05:00:52 GMT
Content-Type: application/octet-stream
Content-Length: 8
Connection: keep-alive
HTTPSampleResult fields:
ContentType: application/octet-stream
DataEncoding: null
Wire Logs below:
DEBUG 09:17:18.034 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - >> "PUT
/tesla/put?name=TG_AUD_3M HTTP/1.1[\r][\n]"
DEBUG 09:17:18.034 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - >>
"Content-Length: 3160[\r][\n]"
DEBUG 09:17:18.034 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - >> "Host:
xxxxx:410[\r][\n]"
DEBUG 09:17:18.034 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - >>
"Connection: Keep-Alive[\r][\n]"
DEBUG 09:17:18.034 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - >>
"User-Agent: Apache-HttpClient/4.1.2 (java 1.5)[\r][\n]"
DEBUG 09:17:18.034 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - >>
"[\r][\n]"
..........
DEBUG 09:17:18.034 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - >> "[\n]"
DEBUG 09:17:18.112 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - <<
"HTTP/1.1 201 Created[\r][\n]"
DEBUG 09:17:18.112 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - <<
"Server: nginx/1.0.4[\r][\n]"
DEBUG 09:17:18.112 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - << "Date:
Thu, 08 Sep 2011 13:17:17 GMT[\r][\n]"
DEBUG 09:17:18.112 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - <<
"Content-Type: application/octet-stream[\r][\n]"
DEBUG 09:17:18.112 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - <<
"Content-Length: 8[\r][\n]"
DEBUG 09:17:18.112 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - <<
"Connection: keep-alive[\r][\n]"
DEBUG 09:17:18.112 - 08/09/2011 [pool-1-thread-1] [] o.a.http.wire - <<
"[\r][\n]"
Shouldn't the default behavior be to reuse the existing sockets (I've even set
the SO_REUSEADDRESS to true, but to no avail). Assistance in troubleshooting
this issue would be greatly appreciated.
Thanks,
____________________________________________________
[cid:[email protected]]
Thomas Kunnumpurath
Assistant Vice President | Application Developer - AS Pricing
Deutsche Bank AG, Filiale New York
Global Rates IT
60 Wall Street, 10005-2836 New York, NY, USA
Tel. +1(212)250-2269
Email [email protected]<mailto:[email protected]>
[cid:[email protected]]
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