1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
|
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
This file is generated from xml source: DO NOT EDIT
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
-->
<title>mod_proxy - Apache HTTP Server</title>
<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
<link href="../images/favicon.ico" rel="shortcut icon" /></head>
<body>
<div id="page-header">
<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
<p class="apache">Apache HTTP Server Version 2.2</p>
<img alt="" src="../images/feather.gif" /></div>
<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
<div id="path">
<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.2</a> > <a href="./">Modules</a></div>
<div id="page-content">
<div id="preamble"><h1>Apache Module mod_proxy</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="../en/mod/mod_proxy.html" title="English"> en </a> |
<a href="../ja/mod/mod_proxy.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a></p>
</div>
<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>HTTP/1.1 proxy/gateway server</td></tr>
<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="module-dict.html#ModuleIdentifier">ModuleIdentifier:</a></th><td>proxy_module</td></tr>
<tr><th><a href="module-dict.html#SourceFile">SourceFile:</a></th><td>mod_proxy.c</td></tr></table>
<h3>Summary</h3>
<div class="warning"><h3>Warning</h3>
<p>Do not enable proxying with <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> until you have <a href="#access">secured your server</a>. Open proxy servers are dangerous both to your
network and to the Internet at large.</p>
</div>
<p>This module implements a proxy/gateway for Apache. It implements
proxying capability for <code>AJP13</code> (Apache JServe Protocol
version 1.3), <code>FTP</code>, <code>CONNECT</code> (for SSL),
<code>HTTP/0.9</code>, <code>HTTP/1.0</code>, and <code>HTTP/1.1</code>.
The module can be configured to connect to other proxy modules for these
and other protocols.</p>
<p>Apache's proxy features are divided into several modules in
addition to <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>:
<code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code>, <code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code>,
<code class="module"><a href="../mod/mod_proxy_ajp.html">mod_proxy_ajp</a></code>, <code class="module"><a href="../mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code>,
and <code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code>. Thus, if you want to use
one or more of the particular proxy functions, load
<code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> <em>and</em> the appropriate module(s)
into the server (either statically at compile-time or dynamically
via the <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code>
directive).</p>
<p>In addition, extended features are provided by other modules.
Caching is provided by <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> and related
modules. The ability to contact remote servers using the SSL/TLS
protocol is provided by the <code>SSLProxy*</code> directives of
<code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code>. These additional modules will need
to be loaded and configured to take advantage of these features.</p>
</div>
<div id="quickview"><h3 class="directives">Directives</h3>
<ul id="toc">
<li><img alt="" src="../images/down.gif" /> <a href="#allowconnect">AllowCONNECT</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#noproxy">NoProxy</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxy"><Proxy></a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxybadheader">ProxyBadHeader</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxyblock">ProxyBlock</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxydomain">ProxyDomain</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxyerroroverride">ProxyErrorOverride</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxyiobuffersize">ProxyIOBufferSize</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxymatch"><ProxyMatch></a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxymaxforwards">ProxyMaxForwards</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxypass">ProxyPass</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxypassreverse">ProxyPassReverse</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxypassreversecookiedomain">ProxyPassReverseCookieDomain</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxypassreversecookiepath">ProxyPassReverseCookiePath</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxypreservehost">ProxyPreserveHost</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxyreceivebuffersize">ProxyReceiveBufferSize</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxyremote">ProxyRemote</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxyremotematch">ProxyRemoteMatch</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxyrequests">ProxyRequests</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxytimeout">ProxyTimeout</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxyvia">ProxyVia</a></li>
</ul>
<h3>Topics</h3>
<ul id="topics">
<li><img alt="" src="../images/down.gif" /> <a href="#forwardreverse">Forward and Reverse Proxies</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#examples">Basic Examples</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#access">Controlling access to your proxy</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#startup">Slow Startup</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#intranet">Intranet Proxy</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#envsettings">Protocol Adjustments</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#request-bodies">Request Bodys</a></li>
</ul><h3>See also</h3>
<ul class="seealso">
<li><code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code></li>
<li><code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code></li>
<li><code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code></li>
<li><code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code></li>
<li><code class="module"><a href="../mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code></li>
<li><code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code></li>
</ul></div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="forwardreverse" id="forwardreverse">Forward and Reverse Proxies</a></h2>
<p>Apache can be configured in both a <dfn>forward</dfn> and
<dfn>reverse</dfn> proxy mode.</p>
<p>An ordinary <dfn>forward proxy</dfn> is an intermediate
server that sits between the client and the <em>origin
server</em>. In order to get content from the origin server,
the client sends a request to the proxy naming the origin server
as the target and the proxy then requests the content from the
origin server and returns it to the client. The client must be
specially configured to use the forward proxy to access other
sites.</p>
<p>A typical usage of a forward proxy is to provide Internet
access to internal clients that are otherwise restricted by a
firewall. The forward proxy can also use caching (as provided
by <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code>) to reduce network usage.</p>
<p>The forward proxy is activated using the <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive. Because
forward proxys allow clients to access arbitrary sites through
your server and to hide their true origin, it is essential that
you <a href="#access">secure your server</a> so that only
authorized clients can access the proxy before activating a
forward proxy.</p>
<p>A <dfn>reverse proxy</dfn>, by contrast, appears to the
client just like an ordinary web server. No special
configuration on the client is necessary. The client makes
ordinary requests for content in the name-space of the reverse
proxy. The reverse proxy then decides where to send those
requests, and returns the content as if it was itself the
origin.</p>
<p>A typical usage of a reverse proxy is to provide Internet
users access to a server that is behind a firewall. Reverse
proxies can also be used to balance load among several back-end
servers, or to provide caching for a slower back-end server.
In addition, reverse proxies can be used simply to bring
several servers into the same URL space.</p>
<p>A reverse proxy is activated using the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive or the
<code>[P]</code> flag to the <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> directive. It is
<strong>not</strong> necessary to turn <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> on in order to
configure a reverse proxy.</p>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="examples" id="examples">Basic Examples</a></h2>
<p>The examples below are only a very basic idea to help you
get started. Please read the documentation on the individual
directives.</p>
<p>In addition, if you wish to have caching enabled, consult
the documentation from <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code>.</p>
<div class="example"><h3>Forward Proxy</h3><p><code>
ProxyRequests On<br />
ProxyVia On<br />
<br />
<Proxy *><br />
<span class="indent">
Order deny,allow<br />
Deny from all<br />
Allow from internal.example.com<br />
</span>
</Proxy>
</code></p></div>
<div class="example"><h3>Reverse Proxy</h3><p><code>
ProxyRequests Off<br />
<br />
<Proxy *><br />
<span class="indent">
Order deny,allow<br />
Allow from all<br />
</span>
</Proxy><br />
<br />
ProxyPass /foo http://foo.example.com/bar<br />
ProxyPassReverse /foo http://foo.example.com/bar
</code></p></div>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="access" id="access">Controlling access to your proxy</a></h2>
<p>You can control who can access your proxy via the <code class="directive"><a href="#proxy"><Proxy></a></code> control block as in
the following example:</p>
<div class="example"><p><code>
<Proxy *><br />
<span class="indent">
Order Deny,Allow<br />
Deny from all<br />
Allow from 192.168.0<br />
</span>
</Proxy>
</code></p></div>
<p>For more information on access control directives, see
<code class="module"><a href="../mod/mod_authz_host.html">mod_authz_host</a></code>.</p>
<p>Strictly limiting access is essential if you are using a
forward proxy (using the <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive).
Otherwise, your server can be used by any client to access
arbitrary hosts while hiding his or her true identity. This is
dangerous both for your network and for the Internet at large.
When using a reverse proxy (using the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive with
<code>ProxyRequests Off</code>), access control is less
critical because clients can only contact the hosts that you
have specifically configured.</p>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="startup" id="startup">Slow Startup</a></h2>
<p>If you're using the <code class="directive"><a href="#proxyblock">ProxyBlock</a></code> directive, hostnames' IP addresses are looked up
and cached during startup for later match test. This may take a few
seconds (or more) depending on the speed with which the hostname lookups
occur.</p>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="intranet" id="intranet">Intranet Proxy</a></h2>
<p>An Apache proxy server situated in an intranet needs to forward
external requests through the company's firewall (for this, configure
the <code class="directive"><a href="#proxyremote">ProxyRemote</a></code> directive
to forward the respective <var>scheme</var> to the firewall proxy).
However, when it has to
access resources within the intranet, it can bypass the firewall when
accessing hosts. The <code class="directive"><a href="#noproxy">NoProxy</a></code>
directive is useful for specifying which hosts belong to the intranet and
should be accessed directly.</p>
<p>Users within an intranet tend to omit the local domain name from their
WWW requests, thus requesting "http://somehost/" instead of
<code>http://somehost.example.com/</code>. Some commercial proxy servers
let them get away with this and simply serve the request, implying a
configured local domain. When the <code class="directive"><a href="#proxydomain">ProxyDomain</a></code> directive is used and the server is <a href="#proxyrequests">configured for proxy service</a>, Apache can return
a redirect response and send the client to the correct, fully qualified,
server address. This is the preferred method since the user's bookmark
files will then contain fully qualified hosts.</p>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="envsettings" id="envsettings">Protocol Adjustments</a></h2>
<p>For circumstances where <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> is sending
requests to an origin server that doesn't properly implement
keepalives or HTTP/1.1, there are two <a href="../env.html">environment variables</a> that can force the
request to use HTTP/1.0 with no keepalive. These are set via the
<code class="directive"><a href="../mod/mod_env.html#setenv">SetEnv</a></code> directive.</p>
<p>These are the <code>force-proxy-request-1.0</code> and
<code>proxy-nokeepalive</code> notes.</p>
<div class="example"><p><code>
<Location /buggyappserver/><br />
<span class="indent">
ProxyPass http://buggyappserver:7001/foo/<br />
SetEnv force-proxy-request-1.0 1<br />
SetEnv proxy-nokeepalive 1<br />
</span>
</Location>
</code></p></div>
</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="request-bodies" id="request-bodies">Request Bodys</a></h2>
<p>Some request methods such as POST include a request body.
The HTTP protocol requires that requests which include a body
either use chunked transfer encoding or send a
<code>Content-Length</code> request header. When passing these
requests on to the origin server, <code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code>
will always attempt to send the <code>Content-Length</code>. But
if the body is large and the original request used chunked
encoding, then chunked encoding may also be used in the upstream
request. You can control this selection using <a href="../env.html">environment variables</a>. Setting
<code>proxy-sendcl</code> ensures maximum compatibility with
upstream servers by always sending the
<code>Content-Length</code>, while setting
<code>proxy-sendchunked</code> minimizes resource usage by using
chunked encoding.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="AllowCONNECT" id="AllowCONNECT">AllowCONNECT</a> <a name="allowconnect" id="allowconnect">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Ports that are allowed to <code>CONNECT</code> through the
proxy</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowCONNECT <var>port</var> [<var>port</var>] ...</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowCONNECT 443 563</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>The <code class="directive">AllowCONNECT</code> directive specifies a list
of port numbers to which the proxy <code>CONNECT</code> method may
connect. Today's browsers use this method when a <code>https</code>
connection is requested and proxy tunneling over HTTP is in effect.</p>
<p>By default, only the default https port (<code>443</code>) and the
default snews port (<code>563</code>) are enabled. Use the
<code class="directive">AllowCONNECT</code> directive to override this default and
allow connections to the listed ports only.</p>
<p>Note that you'll need to have <code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code> present
in the server in order to get the support for the <code>CONNECT</code> at
all.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="NoProxy" id="NoProxy">NoProxy</a> <a name="noproxy" id="noproxy">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Hosts, domains, or networks that will be connected to
directly</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>NoProxy <var>host</var> [<var>host</var>] ...</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>This directive is only useful for Apache proxy servers within
intranets. The <code class="directive">NoProxy</code> directive specifies a
list of subnets, IP addresses, hosts and/or domains, separated by
spaces. A request to a host which matches one or more of these is
always served directly, without forwarding to the configured
<code class="directive"><a href="#proxyremote">ProxyRemote</a></code> proxy server(s).</p>
<div class="example"><h3>Example</h3><p><code>
ProxyRemote * http://firewall.mycompany.com:81<br />
NoProxy .mycompany.com 192.168.112.0/21
</code></p></div>
<p>The <var>host</var> arguments to the <code class="directive">NoProxy</code>
directive are one of the following type list:</p>
<dl>
<dt><var><a name="domain" id="domain">Domain</a></var></dt>
<dd>
<p>A <dfn>Domain</dfn> is a partially qualified DNS domain name, preceded
by a period. It represents a list of hosts which logically belong to the
same DNS domain or zone (<em>i.e.</em>, the suffixes of the hostnames are
all ending in <var>Domain</var>).</p>
<div class="example"><h3>Examples</h3><p><code>
.com .apache.org.
</code></p></div>
<p>To distinguish <var>Domain</var>s from <var><a href="#hostname">Hostname</a></var>s (both syntactically and semantically; a DNS domain can
have a DNS A record, too!), <var>Domain</var>s are always written with a
leading period.</p>
<div class="note"><h3>Note</h3>
<p>Domain name comparisons are done without regard to the case, and
<var>Domain</var>s are always assumed to be anchored in the root of the
DNS tree, therefore two domains <code>.MyDomain.com</code> and
<code>.mydomain.com.</code> (note the trailing period) are considered
equal. Since a domain comparison does not involve a DNS lookup, it is much
more efficient than subnet comparison.</p>
</div></dd>
<dt><var><a name="subnet" id="subnet">SubNet</a></var></dt>
<dd>
<p>A <dfn>SubNet</dfn> is a partially qualified internet address in
numeric (dotted quad) form, optionally followed by a slash and the netmask,
specified as the number of significant bits in the <var>SubNet</var>. It is
used to represent a subnet of hosts which can be reached over a common
network interface. In the absence of the explicit net mask it is assumed
that omitted (or zero valued) trailing digits specify the mask. (In this
case, the netmask can only be multiples of 8 bits wide.) Examples:</p>
<dl>
<dt><code>192.168</code> or <code>192.168.0.0</code></dt>
<dd>the subnet 192.168.0.0 with an implied netmask of 16 valid bits
(sometimes used in the netmask form <code>255.255.0.0</code>)</dd>
<dt><code>192.168.112.0/21</code></dt>
<dd>the subnet <code>192.168.112.0/21</code> with a netmask of 21
valid bits (also used in the form <code>255.255.248.0</code>)</dd>
</dl>
<p>As a degenerate case, a <em>SubNet</em> with 32 valid bits is the
equivalent to an <var><a href="#ipadr">IPAddr</a></var>, while a <var>SubNet</var> with zero
valid bits (<em>e.g.</em>, 0.0.0.0/0) is the same as the constant
<var>_Default_</var>, matching any IP address.</p></dd>
<dt><var><a name="ipaddr" id="ipaddr">IPAddr</a></var></dt>
<dd>
<p>A <dfn>IPAddr</dfn> represents a fully qualified internet address in
numeric (dotted quad) form. Usually, this address represents a host, but
there need not necessarily be a DNS domain name connected with the
address.</p>
<div class="example"><h3>Example</h3><p><code>
192.168.123.7
</code></p></div>
<div class="note"><h3>Note</h3>
<p>An <var>IPAddr</var> does not need to be resolved by the DNS system, so
it can result in more effective apache performance.</p>
</div></dd>
<dt><var><a name="hostname" id="hostname">Hostname</a></var></dt>
<dd>
<p>A <dfn>Hostname</dfn> is a fully qualified DNS domain name which can
be resolved to one or more <var><a href="#ipaddr">IPAddrs</a></var> via the
DNS domain name service. It represents a logical host (in contrast to
<var><a href="#domain">Domain</a></var>s, see above) and must be resolvable
to at least one <var><a href="#ipaddr">IPAddr</a></var> (or often to a list
of hosts with different <var><a href="#ipaddr">IPAddr</a></var>s).</p>
<div class="example"><h3>Examples</h3><p><code>
prep.ai.mit.edu<br />
www.apache.org
</code></p></div>
<div class="note"><h3>Note</h3>
<p>In many situations, it is more effective to specify an <var><a href="#ipaddr">IPAddr</a></var> in place of a <var>Hostname</var> since a
DNS lookup can be avoided. Name resolution in Apache can take a remarkable
deal of time when the connection to the name server uses a slow PPP
link.</p>
<p><var>Hostname</var> comparisons are done without regard to the case,
and <var>Hostname</var>s are always assumed to be anchored in the root
of the DNS tree, therefore two hosts <code>WWW.MyDomain.com</code>
and <code>www.mydomain.com.</code> (note the trailing period) are
considered equal.</p>
</div></dd>
</dl>
<h3>See also</h3>
<ul>
<li><a href="../dns-caveats.html">DNS Issues</a></li>
</ul>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="Proxy" id="Proxy"><Proxy></a> <a name="proxy" id="proxy">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Container for directives applied to proxied resources</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Proxy <var>wildcard-url</var>> ...</Proxy></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>Directives placed in <code class="directive"><Proxy></code>
sections apply only to matching proxied content. Shell-style wildcards are
allowed.</p>
<p>For example, the following will allow only hosts in
<code>yournetwork.example.com</code> to access content via your proxy
server:</p>
<div class="example"><p><code>
<Proxy *><br />
<span class="indent">
Order Deny,Allow<br />
Deny from all<br />
Allow from yournetwork.example.com<br />
</span>
</Proxy>
</code></p></div>
<p>The following example will process all files in the <code>foo</code>
directory of <code>example.com</code> through the <code>INCLUDES</code>
filter when they are sent through the proxy server:</p>
<div class="example"><p><code>
<Proxy http://example.com/foo/*><br />
<span class="indent">
SetOutputFilter INCLUDES<br />
</span>
</Proxy>
</code></p></div>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyBadHeader" id="ProxyBadHeader">ProxyBadHeader</a> <a name="proxybadheader" id="proxybadheader">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines how to handle bad header lines in a
response</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyBadHeader IsError|Ignore|StartBody</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyBadHeader IsError</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>available in Apache 2.0.44 and later</td></tr>
</table>
<p>The <code class="directive">ProxyBadHeader</code> directive determines the
behaviour of <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> if it receives syntactically invalid
header lines (<em>i.e.</em> containing no colon). The following arguments
are possible:</p>
<dl>
<dt><code>IsError</code></dt>
<dd>Abort the request and end up with a 502 (Bad Gateway) response. This is
the default behaviour.</dd>
<dt><code>Ignore</code></dt>
<dd>Treat bad header lines as if they weren't sent.</dd>
<dt><code>StartBody</code></dt>
<dd>When receiving the first bad header line, finish reading the headers and
treat the remainder as body. This helps to work around buggy backend servers
which forget to insert an empty line between the headers and the body.</dd>
</dl>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyBlock" id="ProxyBlock">ProxyBlock</a> <a name="proxyblock" id="proxyblock">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Words, hosts, or domains that are banned from being
proxied</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyBlock *|<var>word</var>|<var>host</var>|<var>domain</var>
[<var>word</var>|<var>host</var>|<var>domain</var>] ...</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>The <code class="directive">ProxyBlock</code> directive specifies a list of
words, hosts and/or domains, separated by spaces. HTTP, HTTPS, and
FTP document requests to sites whose names contain matched words,
hosts or domains are <em>blocked</em> by the proxy server. The proxy
module will also attempt to determine IP addresses of list items which
may be hostnames during startup, and cache them for match test as
well. That may slow down the startup time of the server.</p>
<div class="example"><h3>Example</h3><p><code>
ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu
</code></p></div>
<p><code>rocky.wotsamattau.edu</code> would also be matched if referenced by
IP address.</p>
<p>Note that <code>wotsamattau</code> would also be sufficient to match
<code>wotsamattau.edu</code>.</p>
<p>Note also that</p>
<div class="example"><p><code>
ProxyBlock *
</code></p></div>
<p>blocks connections to all sites.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyDomain" id="ProxyDomain">ProxyDomain</a> <a name="proxydomain" id="proxydomain">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Default domain name for proxied requests</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyDomain <var>Domain</var></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>This directive is only useful for Apache proxy servers within
intranets. The <code class="directive">ProxyDomain</code> directive specifies
the default domain which the apache proxy server will belong to. If a
request to a host without a domain name is encountered, a redirection
response to the same host with the configured <var>Domain</var> appended
will be generated.</p>
<div class="example"><h3>Example</h3><p><code>
ProxyRemote * http://firewall.mycompany.com:81<br />
NoProxy .mycompany.com 192.168.112.0/21<br />
ProxyDomain .mycompany.com
</code></p></div>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyErrorOverride" id="ProxyErrorOverride">ProxyErrorOverride</a> <a name="proxyerroroverride" id="proxyerroroverride">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Override error pages for proxied content</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyErrorOverride On|Off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyErrorOverride Off</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.0 and later</td></tr>
</table>
<p>This directive is useful for reverse-proxy setups, where you want to
have a common look and feel on the error pages seen by the end user.
This also allows for included files (via
<code class="module"><a href="../mod/mod_include.html">mod_include</a></code>'s SSI) to get
the error code and act accordingly (default behavior would display
the error page of the proxied server, turning this on shows the SSI
Error message).</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyIOBufferSize" id="ProxyIOBufferSize">ProxyIOBufferSize</a> <a name="proxyiobuffersize" id="proxyiobuffersize">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determine size of internal data throughput buffer</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyIOBufferSize <var>bytes</var></code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyIOBufferSize 8192</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>The <code class="directive">ProxyIOBufferSize</code> directive adjusts the size
of the internal buffer, which is used as a scratchpad for the data between
input and output. The size must be less or equal <code>8192</code>.</p>
<p>In almost every case there's no reason to change that value.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyMatch" id="ProxyMatch"><ProxyMatch></a> <a name="proxymatch" id="proxymatch">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Container for directives applied to regular-expression-matched
proxied resources</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><ProxyMatch <var>regex</var>> ...</ProxyMatch></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>The <code class="directive"><ProxyMatch></code> directive is
identical to the <code class="directive"><a href="#proxy"><Proxy></a></code> directive, except it matches URLs
using <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expressions</a>.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyMaxForwards" id="ProxyMaxForwards">ProxyMaxForwards</a> <a name="proxymaxforwards" id="proxymaxforwards">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maximium number of proxies that a request can be forwarded
through</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyMaxForwards <var>number</var></code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyMaxForwards 10</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0 and later</td></tr>
</table>
<p>The <code class="directive">ProxyMaxForwards</code> directive specifies the
maximum number of proxies through which a request may pass, if there's no
<code>Max-Forwards</code> header supplied with the request. This is
set to prevent infinite proxy loops, or a DoS attack.</p>
<div class="example"><h3>Example</h3><p><code>
ProxyMaxForwards 15
</code></p></div>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyPass" id="ProxyPass">ProxyPass</a> <a name="proxypass" id="proxypass">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maps remote servers into the local server URL-space</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPass [<var>path</var>] !|<var>url</var> [<var>key=value</var> <var>key=value</var> ...]]</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>This directive allows remote servers to be mapped into the space of
the local server; the local server does not act as a proxy in the
conventional sense, but appears to be a mirror of the remote
server. <var>path</var> is the name of a local virtual path; <var>url</var>
is a partial URL for the remote server and cannot include a query
string.</p>
<div class="warning">The <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive should
usually be set <strong>off</strong> when using
<code class="directive">ProxyPass</code>.</div>
<p>Suppose the local server has address <code>http://example.com/</code>;
then</p>
<div class="example"><p><code>
ProxyPass /mirror/foo/ http://backend.example.com/
</code></p></div>
<p>will cause a local request for
<code>http://example.com/mirror/foo/bar</code> to be internally converted
into a proxy request to <code>http://backend.example.com/bar</code>.</p>
<p>The <code>!</code> directive is useful in situations where you don't want
to reverse-proxy a subdirectory, <em>e.g.</em></p>
<div class="example"><p><code>
ProxyPass /mirror/foo/i !<br />
ProxyPass /mirror/foo http://backend.example.com
</code></p></div>
<p>will proxy all requests to <code>/mirror/foo</code> to
<code>backend.example.com</code> <em>except</em> requests made to
<code>/mirror/foo/i</code>.</p>
<div class="note"><h3>Note</h3>
<p>Order is important. you need to put the exclusions <em>before</em> the
general <code class="directive">ProxyPass</code> directive.</p>
</div>
<p>As of Apache 2.1, the ability to use pooled connections to a backend
server is available. Using the <code>key=value</code> parameters it is
possible to tune this connection pooling. The default for a <code>Hard
Maximum</code> for the number of connections is the number of threads per
process in the active MPM. In the Prefork MPM, this is always 1, while with
the Worker MPM it is controlled by the
<code class="directive">ThreadsPerChild</code>.</p>
<p>Setting <code>min</code> will determine how many connections will always
be open to the backend server. Upto the Soft Maximum or <code>smax</code>
number of connections will be created on demand. Any connections above
<code>smax</code> are subject to a time to live or <code>ttl</code>. Apache
will never create more than the Hard Maximum or <code>max</code> connections
to the backend server.</p>
<div class="example"><p><code>
ProxyPass /example http://backend.example.com smax=5 max=20 ttl=120 retry=300
</code></p></div>
<table>
<tr><th>Parameter</th>
<th>Default</th>
<th>Description</th></tr>
<tr><td>min</td>
<td>0</td>
<td>Minumum number of connections that will always
be open to the backend server.</td></tr>
<tr><td>max</td>
<td>1...n</td>
<td>Hard Maximum number of connections that will be
allowed to the backend server. The default for a Hard Maximum
for the number of connections is the number of threads per process in the
active MPM. In the Prefork MPM, this is always 1, while with the Worker MPM
it is controlled by the <code class="directive">ThreadsPerChild</code>.
Apache will never create more than the Hard Maximum connections
to the backend server.</td></tr>
<tr><td>smax</td>
<td>max</td>
<td>Upto the Soft Maximum
number of connections will be created on demand. Any connections above
<code>smax</code> are subject to a time to live or <code>ttl</code>.
</td></tr>
<tr><td>ttl</td>
<td>-</td>
<td>Time To Live for the inactive connections above the
<code>smax</code> connections in seconds. Apache will close all
connections that has not been used inside that time period.
</td></tr>
<tr><td>timeout</td>
<td><code class="directive">Timeout</code></td>
<td>Connection timeout in seconds.
If not set the Apache will wait until the free connection
is available. This directive is used for limiting the number
of connections to the backend server together with <code>max</code>
parameter.
</td></tr>
<tr><td>acquire</td>
<td>-</td>
<td>If set this will be the maximum time to wait for a free
connection in the connection pool. If there are no free connections
in the pool the Apache will return <code>SERVER_BUSY</code> status to
the client.
</td></tr>
<tr><td>keepalive</td>
<td>Off</td>
<td>This parameter should be used when you have a firewall between your
Apache and the backend server, who tend to drop inactive connections.
This flag will tell the Operating System to send <code>KEEP_ALIVE</code>
messages on inactive connections (interval depends on global OS settings,
generally 120ms), and thus prevent the firewall to drop the connection.
To enable keepalive set this property value to <code>On</code>.
</td></tr>
<tr><td>retry</td>
<td>60</td>
<td>Connection pool worker retry timeout in seconds.
If the connection pool worker to the backend server is in the error state,
Apache will not forward any requests to that server until the timeout
expires. This enables to shut down the backend server for maintenance,
and bring it back online later.
</td></tr>
<tr><td>loadfactor</td>
<td>1</td>
<td>Worker load factor. Used with BalancerMember.
It is a number between 1 and 100 and defines the normalized weighted
load applied to the worker.
</td></tr>
<tr><td>route</td>
<td>-</td>
<td>Route of the worker when used inside load balancer.
The route is a value appended to seesion id.
</td></tr>
<tr><td>redirect</td>
<td>-</td>
<td>Redirection Route of the worker. This value is usually
set dynamically to enable safe removal of the node from
the cluster. If set all requests without session id will be
redirected to the BalancerMember that has route parametar
equal as this value.
</td></tr>
</table>
<p>If the Proxy directive scheme starts with the
<code>balancer://</code> then a virtual worker that does not really
communicate with the backend server will be created. Instead it is responsible
for the management of several "real" workers. In that case the special set of
parameters can be add to this virtual worker.
</p>
<table>
<tr><th>Parameter</th>
<th>Default</th>
<th>Description</th></tr>
<tr><td>lbmethod</td>
<td>-</td>
<td>Balancer load-balance method. Select the load-balancing scheduler
method to use. Either <code>byrequests</code>, to perform weighted
request counting or <code>bytraffic</code>, to perform weighted
traffic byte count balancing. Default is <code>byrequests</code>.
</td></tr>
<tr><td>stickysession</td>
<td>-</td>
<td>Balancer sticky session name. The value is usually set to something
like <code>JSESSIONID</code> or <code>PHPSESSIONID</code>,
and it depends on the backend application server that support sessions.
</td></tr>
<tr><td>nofailover</td>
<td>Off</td>
<td>If set to <code>On</code> the session will break if the worker is in
error state or disabled. Set this value to On if backend servers do not
support session replication.
</td></tr>
<tr><td>timeout</td>
<td>0</td>
<td>Balancer timeout in seconds. If set this will be the maximum time
to wait for a free worker. Default is not to wait.
</td></tr>
<tr><td>maxattempts</td>
<td>1</td>
<td>Maximum number of failover attempts before giving up.
</td></tr>
</table>
<div class="example"><p><code>
ProxyPass /special-area http://special.example.com/ smax=5 max=10<br />
ProxyPass / balancer://mycluster stickysession=jsessionid nofailover=On<br />
<Proxy balancer://mycluster><br />
<span class="indent">
BalancerMember http://1.2.3.4:8009<br />
BalancerMember http://1.2.3.5:8009 smax=10<br />
# Less powerful server, don't send as many requests there<br />
BalancerMember http://1.2.3.6:8009 smax=1 loadfactor=20<br />
</span>
</Proxy>
</code></p></div>
<p>When used inside a <code class="directive"><a href="../mod/core.html#location"><Location></a></code> section, the first argument is omitted and the local
directory is obtained from the <code class="directive"><a href="../mod/core.html#location"><Location></a></code>.</p>
<p>If you require a more flexible reverse-proxy configuration, see the
<code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> directive with the
<code>[P]</code> flag.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyPassReverse" id="ProxyPassReverse">ProxyPassReverse</a> <a name="proxypassreverse" id="proxypassreverse">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Adjusts the URL in HTTP response headers sent from a reverse
proxied server</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassReverse [<var>path</var>] <var>url</var></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>This directive lets Apache adjust the URL in the <code>Location</code>,
<code>Content-Location</code> and <code>URI</code> headers on HTTP redirect
responses. This is essential when Apache is used as a reverse proxy to avoid
by-passing the reverse proxy because of HTTP redirects on the backend
servers which stay behind the reverse proxy.</p>
<p>Only the HTTP response headers specifically mentioned above
will be rewritten. Apache will not rewrite other response
headers, nor will it rewrite URL references inside HTML pages.
This means that if the proxied content contains absolute URL
references, they will by-pass the proxy. A third-party module
that will look inside the HTML and rewrite URL references is Nick
Kew's <a href="http://apache.webthing.com/mod_proxy_html/">mod_proxy_html</a>.</p>
<p><var>path</var> is the name of a local virtual path. <var>url</var> is a
partial URL for the remote server - the same way they are used for the
<code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.</p>
<p>For example, suppose the local server has address
<code>http://example.com/</code>; then</p>
<div class="example"><p><code>
ProxyPass /mirror/foo/ http://backend.example.com/<br />
ProxyPassReverse /mirror/foo/ http://backend.example.com/<br />
ProxyPassReverseCookieDomain backend.example.com public.example.com<br />
ProxyPassReverseCookiePath / /mirror/foo/
</code></p></div>
<p>will not only cause a local request for the
<code>http://example.com/mirror/foo/bar</code> to be internally converted
into a proxy request to <code>http://backend.example.com/bar</code>
(the functionality <code>ProxyPass</code> provides here). It also takes care
of redirects the server <code>backend.example.com</code> sends: when
<code>http://backend.example.com/bar</code> is redirected by him to
<code>http://backend.example.com/quux</code> Apache adjusts this to
<code>http://example.com/mirror/foo/quux</code> before forwarding the HTTP
redirect response to the client. Note that the hostname used for
constructing the URL is chosen in respect to the setting of the <code class="directive"><a href="../mod/core.html#usecanonicalname">UseCanonicalName</a></code> directive.</p>
<p>Note that this <code class="directive">ProxyPassReverse</code> directive can
also be used in conjunction with the proxy pass-through feature
(<code>RewriteRule ... [P]</code>) from <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>
because it doesn't depend on a corresponding <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.</p>
<p>When used inside a <code class="directive"><a href="../mod/core.html#location"><Location></a></code> section, the first argument is omitted and the local
directory is obtained from the <code class="directive"><a href="../mod/core.html#location"><Location></a></code>.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyPassReverseCookieDomain" id="ProxyPassReverseCookieDomain">ProxyPassReverseCookieDomain</a> <a name="proxypassreversecookiedomain" id="proxypassreversecookiedomain">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Adjusts the Domain string in Set-Cookie headers from a reverse-
proxied server</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassReverseCookieDomain <var>internal-domain</var> <var>public-domain</var></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>Usage is basically similar to
<code class="directive"><a href="#proxypassreverse">ProxyPassReverse</a></code>, but instead of
rewriting headers that are a URL, this rewrites the <code>domain</code>
string in <code>Set-Cookie</code> headers.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyPassReverseCookiePath" id="ProxyPassReverseCookiePath">ProxyPassReverseCookiePath</a> <a name="proxypassreversecookiepath" id="proxypassreversecookiepath">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Adjusts the Path string in Set-Cookie headers from a reverse-
proxied server</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassReverseCookiePath <var>internal-path</var> <var>public-path</var></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>Usage is basically similar to
<code class="directive"><a href="#proxypassreverse">ProxyPassReverse</a></code>, but instead of
rewriting headers that are a URL, this rewrites the <code>path</code>
string in <code>Set-Cookie</code> headers.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyPreserveHost" id="ProxyPreserveHost">ProxyPreserveHost</a> <a name="proxypreservehost" id="proxypreservehost">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use incoming Host HTTP request header for proxy
request</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPreserveHost On|Off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyPreserveHost Off</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.31 and later.</td></tr>
</table>
<p>When enabled, this option will pass the Host: line from the incoming
request to the proxied host, instead of the hostname specified in the
<code class="directive">ProxyPass</code> line.</p>
<p>This option should normally be turned <code>Off</code>. It is mostly
useful in special configurations like proxied mass name-based virtual
hosting, where the original Host header needs to be evaluated by the
backend server.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyReceiveBufferSize" id="ProxyReceiveBufferSize">ProxyReceiveBufferSize</a> <a name="proxyreceivebuffersize" id="proxyreceivebuffersize">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Network buffer size for proxied HTTP and FTP
connections</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyReceiveBufferSize <var>bytes</var></code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyReceiveBufferSize 0</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>The <code class="directive">ProxyReceiveBufferSize</code> directive specifies an
explicit (TCP/IP) network buffer size for proxied HTTP and FTP connections,
for increased throughput. It has to be greater than <code>512</code> or set
to <code>0</code> to indicate that the system's default buffer size should
be used.</p>
<div class="example"><h3>Example</h3><p><code>
ProxyReceiveBufferSize 2048
</code></p></div>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyRemote" id="ProxyRemote">ProxyRemote</a> <a name="proxyremote" id="proxyremote">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Remote proxy used to handle certain requests</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRemote <var>match</var> <var>remote-server</var></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>This defines remote proxies to this proxy. <var>match</var> is either the
name of a URL-scheme that the remote server supports, or a partial URL
for which the remote server should be used, or <code>*</code> to indicate
the server should be contacted for all requests. <var>remote-server</var> is
a partial URL for the remote server. Syntax:</p>
<div class="example"><p><code>
<dfn>remote-server</dfn> =
<var>scheme</var>://<var>hostname</var>[:<var>port</var>]
</code></p></div>
<p><var>scheme</var> is effectively the protocol that should be used to
communicate with the remote server; only <code>http</code> is supported by
this module.</p>
<div class="example"><h3>Example</h3><p><code>
ProxyRemote http://goodguys.com/ http://mirrorguys.com:8000<br />
ProxyRemote * http://cleversite.com<br />
ProxyRemote ftp http://ftpproxy.mydomain.com:8080
</code></p></div>
<p>In the last example, the proxy will forward FTP requests, encapsulated
as yet another HTTP proxy request, to another proxy which can handle
them.</p>
<p>This option also supports reverse proxy configuration - a backend
webserver can be embedded within a virtualhost URL space even if that
server is hidden by another forward proxy.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyRemoteMatch" id="ProxyRemoteMatch">ProxyRemoteMatch</a> <a name="proxyremotematch" id="proxyremotematch">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Remote proxy used to handle requests matched by regular
expressions</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRemoteMatch <var>regex</var> <var>remote-server</var></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>The <code class="directive">ProxyRemoteMatch</code> is identical to the
<code class="directive"><a href="#proxyremote">ProxyRemote</a></code> directive, except the
first argument is a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expression</a>
match against the requested URL.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyRequests" id="ProxyRequests">ProxyRequests</a> <a name="proxyrequests" id="proxyrequests">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables forward (standard) proxy requests</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRequests On|Off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyRequests Off</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>This allows or prevents Apache from functioning as a forward proxy
server. (Setting ProxyRequests to <code>Off</code> does not disable use of
the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.)</p>
<p>In a typical reverse proxy configuration, this option should be set to
<code>Off</code>.</p>
<p>In order to get the functionality of proxying HTTP or FTP sites, you
need also <code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code> or <code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code>
(or both) present in the server.</p>
<div class="warning"><h3>Warning</h3>
<p>Do not enable proxying with <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> until you have <a href="#access">secured your server</a>. Open proxy servers are dangerous
both to your network and to the Internet at large.</p>
</div>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyTimeout" id="ProxyTimeout">ProxyTimeout</a> <a name="proxytimeout" id="proxytimeout">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Network timeout for proxied requests</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyTimeout <var>seconds</var></code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyTimeout 300</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.31 and later</td></tr>
</table>
<p>This directive allows a user to specifiy a timeout on proxy requests.
This is useful when you have a slow/buggy appserver which hangs, and you
would rather just return a timeout and fail gracefully instead of waiting
however long it takes the server to return.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyVia" id="ProxyVia">ProxyVia</a> <a name="proxyvia" id="proxyvia">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Information provided in the <code>Via</code> HTTP response
header for proxied requests</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyVia On|Off|Full|Block</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyVia Off</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
</table>
<p>This directive controls the use of the <code>Via:</code> HTTP
header by the proxy. Its intended use is to control the flow of
proxy requests along a chain of proxy servers. See <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a> (HTTP/1.1), section
14.45 for an explanation of <code>Via:</code> header lines.</p>
<ul>
<li>If set to <code>Off</code>, which is the default, no special processing
is performed. If a request or reply contains a <code>Via:</code> header,
it is passed through unchanged.</li>
<li>If set to <code>On</code>, each request and reply will get a
<code>Via:</code> header line added for the current host.</li>
<li>If set to <code>Full</code>, each generated <code>Via:</code> header
line will additionally have the Apache server version shown as a
<code>Via:</code> comment field.</li>
<li>If set to <code>Block</code>, every proxy request will have all its
<code>Via:</code> header lines removed. No new <code>Via:</code> header will
be generated.</li>
</ul>
</div>
</div>
<div class="bottomlang">
<p><span>Available Languages: </span><a href="../en/mod/mod_proxy.html" title="English"> en </a> |
<a href="../ja/mod/mod_proxy.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a></p>
</div><div id="footer">
<p class="apache">Copyright 2006 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div>
</body></html>
|
