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
|
<!--#if expr="$FAQMASTER" -->
<!--#set var="STANDALONE" value="" -->
<!--#set var="INCLUDED" value="YES" -->
<!--#if expr="$QUERY_STRING = TOC" -->
<!--#set var="TOC" value="YES" -->
<!--#set var="CONTENT" value="" -->
<!--#else -->
<!--#set var="TOC" value="" -->
<!--#set var="CONTENT" value="YES" -->
<!--#endif -->
<!--#else -->
<!--#set var="STANDALONE" value="YES" -->
<!--#set var="INCLUDED" value="" -->
<!--#set var="TOC" value="" -->
<!--#set var="CONTENT" value="" -->
<!--#endif -->
<!--#if expr="$STANDALONE" -->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<HTML>
<HEAD>
<TITLE>Apache Server Frequently Asked Questions</TITLE>
</HEAD>
<!-- Background white, links blue (unvisited), navy (visited), red (active) -->
<BODY
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#000080"
ALINK="#FF0000"
>
<!--#include virtual="header.html" -->
<H1 ALIGN="CENTER">Apache Server Frequently Asked Questions</H1>
<P>
$Revision: 1.8 $ ($Date: 2001/02/28 03:35:59 $)
</P>
<P>
The latest version of this FAQ is always available from the main
Apache web site, at
<<A
HREF="http://www.apache.org/docs/misc/FAQ.html"
REL="Help"
><SAMP>http://www.apache.org/docs/misc/FAQ.html</SAMP></A>>.
</P>
<!-- Notes about changes: -->
<!-- - If adding a relative link to another part of the -->
<!-- documentation, *do* include the ".html" portion. There's a -->
<!-- good chance that the user will be reading the documentation -->
<!-- on his own system, which may not be configured for -->
<!-- multiviews. -->
<!-- - When adding items, make sure they're put in the right place -->
<!-- - verify that the numbering matches up. -->
<!-- - *Don't* use <PRE></PRE> blocks - they don't appear -->
<!-- correctly in a reliable way when this is converted to text -->
<!-- with Lynx. Use <DL><DD><CODE>xxx<BR>xx</CODE></DD></DL> -->
<!-- blocks inside a <P></P> instead. This is necessary to get -->
<!-- the horizontal and vertical indenting right. -->
<!-- - Don't forget to include an HR tag after the last /P tag -->
<!-- but before the /LI in an item. -->
<P>
If you are reading a text-only version of this FAQ, you may find numbers
enclosed in brackets (such as "[12]"). These refer to the list of
reference URLs to be found at the end of the document. These references
do not appear, and are not needed, for the hypertext version.
</P>
<H2>The Questions</H2>
<OL TYPE="A">
<!--#endif -->
<!--#if expr="$TOC || $STANDALONE" -->
<LI VALUE="4"><STRONG>Error Log Messages and Problems Starting Apache</STRONG>
<OL>
<LI><A HREF="#setgid">Why do I get "<SAMP>setgid: Invalid
argument</SAMP>" at startup?</A>
</LI>
<LI><A HREF="#nodelay">Why am I getting "<SAMP>httpd: could not
set socket option TCP_NODELAY</SAMP>" in my error log?</A>
</LI>
<LI><A HREF="#peerreset">Why am I getting "<SAMP>connection
reset by peer</SAMP>" in my error log?</A>
</LI>
<LI><A HREF="#wheres-the-dump">The errorlog says Apache dumped core,
but where's the dump file?</A>
</LI>
<LI><A HREF="#linux-shmget">When I run it under Linux I get "shmget:
function not found", what should I do?</A>
</LI>
<LI><A HREF="#nfslocking">Server hangs, or fails to start, and/or error log
fills with "<SAMP>fcntl: F_SETLKW: No record locks
available</SAMP>" or similar messages</A>
</LI>
<LI><A HREF="#aixccbug">Why am I getting "<SAMP>Expected </Directory>
but saw </Directory></SAMP>" when I try to start Apache?</A>
</LI>
<LI><A HREF="#redhat">I'm using RedHat Linux and I have problems with httpd
dying randomly or not restarting properly</A>
</LI>
<LI><A HREF="#stopping">I upgraded from an Apache version earlier
than 1.2.0 and suddenly I have problems with Apache dying randomly
or not restarting properly</A>
</LI>
<LI><A HREF="#setservername">When I try to start Apache from a DOS
window, I get a message like "<samp>Cannot determine host name.
Use ServerName directive to set it manually.</samp>" What does
this mean?</A>
</LI>
<LI><A HREF="#ws2_32dll">When I try to start Apache for Windows, I get a message
like "<samp>Unable To Locate WS2_32.DLL...</samp>". What should I do?</A>
</LI>
<LI><A HREF="#WSADuplicateSocket">Apache for Windows does not start.
Error log contains this message "<samp>[crit] (10045) The attempted
operation is not supported for the type of object referenced: Parent:
WSADuplicateSocket failed for socket ###</samp>". What does this
mean?</a>
</LI>
</OL>
</LI>
<!--#endif -->
<!--#if expr="$STANDALONE" -->
</OL>
<HR>
<H2>The Answers</H2>
<!--#endif -->
<!--#if expr="! $TOC" -->
<H3>D. Error Log Messages and Problems Starting Apache</H3>
<OL>
<LI><A NAME="setgid">
<STRONG>Why do I get "<SAMP>setgid: Invalid
argument</SAMP>" at startup?</STRONG>
</A>
<P>
Your
<A HREF="../mod/mpm_common.html#group"><SAMP>Group</SAMP></A>
directive (probably in <SAMP>conf/httpd.conf</SAMP>) needs to name a
group that actually exists in the <SAMP>/etc/group</SAMP> file (or
your system's equivalent). This problem is also frequently seen when
a negative number is used in the <CODE>Group</CODE> directive
(<EM>e.g.</EM>, "<CODE>Group #-1</CODE>"). Using a group name
-- not group number -- found in your system's group database should
solve this problem in all cases.
</P>
<HR>
</LI>
<LI><A NAME="nodelay">
<STRONG>Why am I getting "<SAMP>httpd: could not set socket
option TCP_NODELAY</SAMP>" in my error log?</STRONG>
</A>
<P>
This message almost always indicates that the client disconnected
before Apache reached the point of calling <CODE>setsockopt()</CODE>
for the connection. It shouldn't occur for more than about 1% of the
requests your server handles, and it's advisory only in any case.
</P>
<HR>
</LI>
<LI><A NAME="peerreset">
<STRONG>Why am I getting "<SAMP>connection reset by
peer</SAMP>" in my error log?</STRONG>
</A>
<P>
This is a normal message and nothing about which to be alarmed. It simply
means that the client canceled the connection before it had been
completely set up - such as by the end-user pressing the "Stop"
button. People's patience being what it is, sites with response-time
problems or slow network links may experiences this more than
high-capacity ones or those with large pipes to the network.
</P>
<HR>
</LI>
<LI><A NAME="wheres-the-dump">
<STRONG>The errorlog says Apache dumped core, but where's the dump
file?</STRONG>
</A>
<P>
In Apache version 1.2, the error log message
about dumped core includes the directory where the dump file should be
located. However, many Unixes do not allow a process that has
called <CODE>setuid()</CODE> to dump core for security reasons;
the typical Apache setup has the server started as root to bind to
port 80, after which it changes UIDs to a non-privileged user to
serve requests.
</P>
<P>
Dealing with this is extremely operating system-specific, and may
require rebuilding your system kernel. Consult your operating system
documentation or vendor for more information about whether your system
does this and how to bypass it. If there <EM>is</EM> a documented way
of bypassing it, it is recommended that you bypass it only for the
<SAMP>httpd</SAMP> server process if possible.
</P>
<P>
The canonical location for Apache's core-dump files is the
<A HREF="../mod/core.html#serverroot">ServerRoot</A>
directory. As of Apache version 1.3, the location can be set <EM>via</EM>
the
<A HREF="../mod/mpm_common.html#coredumpdirectory"
><SAMP>CoreDumpDirectory</SAMP></A>
directive to a different directory. Make sure that this directory is
writable by the user the server runs as (as opposed to the user the server
is <EM>started</EM> as).
</P>
<HR>
</LI>
<LI><A NAME="linux-shmget">
<STRONG>When I run it under Linux I get "shmget:
function not found", what should I do?</STRONG>
</A>
<P>
Your kernel has been built without SysV IPC support. You will have
to rebuild the kernel with that support enabled (it's under the
"General Setup" submenu). Documentation for kernel
building is beyond the scope of this FAQ; you should consult the <A
HREF="http://www.redhat.com/mirrors/LDP/HOWTO/Kernel-HOWTO.html">Kernel
HOWTO</A>, or the documentation provided with your distribution, or
a <A HREF="http://www.redhat.com/mirrors/LDP/HOWTO/META-FAQ.html">Linux
newsgroup/mailing list</A>. As a last-resort workaround, you can
comment out the <CODE>#define USE_SHMGET_SCOREBOARD</CODE>
definition in the <SAMP>LINUX</SAMP> section of
<SAMP>src/conf.h</SAMP> and rebuild the server (prior to 1.3b4,
simply removing <CODE>#define HAVE_SHMGET</CODE> would have
sufficed). This will produce a server which is slower and less
reliable.
</P>
<HR>
</LI>
<LI><A NAME="nfslocking">
<STRONG>Server hangs, or fails to start, and/or error log
fills with "<SAMP>fcntl: F_SETLKW: No record locks
available</SAMP>" or similar messages</STRONG>
</A>
<P>
These are symptoms of a fine locking problem, which usually means that
the server is trying to use a synchronization file on an NFS filesystem.
</P>
<P>
Because of its parallel-operation model, the Apache Web server needs to
provide some form of synchronization when accessing certain resources.
One of these synchronization methods involves taking out locks on a file,
which means that the filesystem whereon the lockfile resides must support
locking. In many cases this means it <EM>can't</EM> be kept on an
NFS-mounted filesystem.
</P>
<P>
To cause the Web server to work around the NFS locking limitations, include
a line such as the following in your server configuration files:
</P>
<DL>
<DD><CODE>LockFile /var/run/apache-lock</CODE>
</DD>
</DL>
<P>
The directory should not be generally writable (<EM>e.g.</EM>, don't use
<SAMP>/var/tmp</SAMP>).
See the <A HREF="../mod/mpm_common.html#lockfile"><SAMP>LockFile</SAMP></A>
documentation for more information.
</P>
<HR>
</LI>
<LI><A NAME="aixccbug"><STRONG>Why am I getting "<SAMP>Expected
</Directory> but saw </Directory></SAMP>" when
I try to start Apache?</STRONG></A>
<P>
This is a known problem with certain versions of the AIX C compiler.
IBM are working on a solution, and the issue is being tracked by
<A HREF="http://bugs.apache.org/index/full/2312">problem report #2312</A>.
</P>
<HR>
</LI>
<LI><A NAME="redhat">
<STRONG>I'm using RedHat Linux and I have problems with httpd
dying randomly or not restarting properly</STRONG>
</A>
<P>
RedHat Linux versions 4.x (and possibly earlier) RPMs contain
various nasty scripts which do not stop or restart Apache properly.
These can affect you even if you're not running the RedHat supplied
RPMs.
</P>
<P>
If you're using the default install then you're probably running
Apache 1.1.3, which is outdated. From RedHat's ftp site you can
pick up a more recent RPM for Apache 1.2.x. This will solve one of
the problems.
</P>
<P>
If you're using a custom built Apache rather than the RedHat RPMs
then you should <CODE>rpm -e apache</CODE>. In particular you want
the mildly broken <CODE>/etc/logrotate.d/apache</CODE> script to be
removed, and you want the broken <CODE>/etc/rc.d/init.d/httpd</CODE>
(or <CODE>httpd.init</CODE>) script to be removed. The latter is
actually fixed by the apache-1.2.5 RPMs but if you're building your
own Apache then you probably don't want the RedHat files.
</P>
<P>
We can't stress enough how important it is for folks, <EM>especially
vendors</EM> to follow the <A HREF="../stopping.html">stopping Apache
directions</A> given in our documentation. In RedHat's defense,
the broken scripts were necessary with Apache 1.1.x because the
Linux support in 1.1.x was very poor, and there were various race
conditions on all platforms. None of this should be necessary with
Apache 1.2 and later.
</P>
<HR>
</LI>
<LI><A NAME="stopping">
<STRONG>I upgraded from an Apache version earlier
than 1.2.0 and suddenly I have problems with Apache dying randomly
or not restarting properly</STRONG>
</A>
<P>
You should read <A HREF="#redhat">the previous note</A> about
problems with RedHat installations. It is entirely likely that your
installation has start/stop/restart scripts which were built for
an earlier version of Apache. Versions earlier than 1.2.0 had
various race conditions that made it necessary to use
<CODE>kill -9</CODE> at times to take out all the httpd servers.
But that should not be necessary any longer. You should follow
the <A HREF="../stopping.html">directions on how to stop
and restart Apache</A>.
</P>
<P>As of Apache 1.3 there is a script
<CODE>src/support/apachectl</CODE> which, after a bit of
customization, is suitable for starting, stopping, and restarting
your server.
</P>
<HR>
</LI>
<LI><A name="setservername">
<b>When I try to start Apache from a DOS
window, I get a message like "<samp>Cannot determine host name.
Use ServerName directive to set it manually.</samp>" What does
this mean?</b></A>
<p>
It means what it says; the Apache software can't determine the
hostname of your system. Edit your <samp>conf\httpd.conf</samp>
file, look for the string "ServerName", and make sure there's an
uncommented directive such as
</p>
<dl>
<dd><code>ServerName localhost</code></dd>
</dl>
<p>
or
</p>
<dl>
<dd><code>ServerName www.foo.com</code></dd>
</dl>
<p>
in the file. Correct it if there one there with wrong information, or
add one if you don't already have one.
</p>
<p>
Also, make sure that your Windows system has DNS enabled. See the TCP/IP
setup component of the Networking or Internet Options control panel.
</p>
<p>
After verifying that DNS is enabled and that you have a valid hostname
in your <samp>ServerName</samp> directive, try to start the server
again.
</p>
<hr>
</LI>
<LI><A name="ws2_32dll">
<b>When I try to start Apache for Windows, I get a message
like "<samp>Unable To Locate WS2_32.DLL...</samp>". What should I do?</b></A>
<p>
Short answer: You need to install Winsock 2, available from
<A HREF="http://www.microsoft.com/windows95/downloads/">http://www.microsoft.com/windows95/downloads/</A>
</p>
<p>
Detailed answer: Prior to version 1.3.9, Apache for Windows used Winsock 1.1. Beginning with
version 1.3.9, Apache began using Winsock 2 features (specifically, WSADuplicateSocket()).
WS2_32.DLL implements the Winsock 2 API. Winsock 2 ships with Windows NT 4.0 and Windows 98.
Some of the earlier releases of Windows 95 did not include Winsock 2.
</p>
<hr>
</LI>
<LI><A name="WSADuplicateSocket">
<b>Apache for Windows does not start. Error log contains this message:
"<samp>[crit] (10045) The attempted operation is not supported for
the type of object referenced: Parent: WSADuplicateSocket failed for
socket ###</samp>". What does this mean?</b></A>
<p>
We have seen this problem when Apache is run on systems along with
Virtual Private Networking clients like Aventail Connect. Aventail Connect
is a Layered Service Provider (LSP) that inserts itself, as a "shim,"
between the Winsock 2 API and Window's native Winsock 2 implementation.
The Aventail Connect shim does not implement WSADuplicateSocket, which is
the cause of the failure.
</p>
<p>
The shim is not unloaded when Aventail Connect is shut down. Once
observed, the problem persists until the shim is either explicitly
unloaded or the machine is rebooted. Instructions for temporarily
removing the Aventail Connect V3.x shim can be found here:
"<a href="http://support.aventail.com/akb/article00386.html"
>How to Remove Aventail Connect v3.x from the LSP Order for Testing
Purposes</a>."
</p>
<p>
Another potential solution (not tested) is to add <code>apache.exe</code>
to the Aventail "Connect Exclusion List". See this link for details:
"<a href="http://support.aventail.com/akb/article00586.html"
>How to Add an Application to Aventail Connect's Application Exclusion
List</a>."
</p>
<hr>
</LI>
</OL>
<!--#endif -->
<!--#if expr="$STANDALONE" -->
<!-- Don't forget to add HR tags at the end of each list item.. -->
<!--#include virtual="footer.html" -->
</BODY>
</HTML>
<!--#endif -->
|
