You are viewing a plain text version of this content. The canonical link for it is here.
Posted to users@httpd.apache.org by "Coulter, Ryan" <rc...@healtheast.org> on 2007/08/27 17:31:12 UTC
[users@httpd] Help with Apache 2 problem on AIX 5.3
(My apologies for sending this earlier with no subject.)
Hello. I am stumped by a problem I'm having with Apache 2 and IHS 2 on AIX
5.3. I have tried this scenario with both a custom compiled Apache 2.2.4 as
well as IHS 2.0.47. In both cases, the behavior is identical. Using Apache
1.3, I don't have the problem. I have been researching the problem for
several days, but can not find any issue that describes the behavior I¹m
seeing. The problem is as follows:
I request index.html from the webserver and receive it properly in my
browser. I then log onto the server, edit the file with vi, save it and
exit. Then I return to my browser and request index.html again and it
appears as though nothing has changed. My edit does not show up. Sometimes,
after making an edit, I try to open the page in my browser and receive a
message that the browser couldn't reach the server.
In trying to track down the problem, I have discovered that, first, the web
server is not crashing. It is also receiving and logging the GET request for
the page. When it logs the request, it logs a 200 OK and the correct *new*
file size. I then performed an experiment using wget to request index.html.
On the first request, I receive the correct version. After editing
index.html on the server and adding a large number of characters, I submit
the request with wget again and receive an error saying "No data received."
After a few minutes, the requests begin to work again and I receive the
correct, new version. After editing the file again and removing any number
of characters, I make the request again and receive a file of the correct,
new size. However, the contents of the file when opened still contain the
removed characters, and the file itself is truncated by the same number of
characters I had removed.
My initial thoughts were that the problem had to do with memory caching or
disk caching in Apache, but I have confirmed that those modules are not
loaded. No caching is enabled. Also, no errors are logged. Stopping and
starting Apache makes no difference. I can even completely remove and
reinstall the Apache files, including the document root, and upon starting
up Apache, it will continue for several minutes with this behavior. In every
case, eventually, after several minutes, the correct, new file will be
delivered properly.
Over the weekend I tested the configuration on both Linux and OS X, and did
not have any problems. One other test I performed before the weekend went as
follows:
I had just edited the file index.html and confirmed that Apache was not
sending it correctly. I went on the AIX server, shut down Apache, completely
removed the server root, including the document root where index.html was
stored. Took the time to compile a brand new copy of 2.2.4 ensuring that all
the caching options were disabled. Installed the new version and configured
it. Copied a new index.html into the document root and started the server.
All of this took 30 to 45 minutes, and when I first requested the page with
wget, I received the same broken file I had last received from the Apache
process I had shutdown earlier. After a 3 or 4 minutes went past, the server
started serving the new index.html correctly.
This is happening on more than one AIX server. I am really confused. Has
anyone seen anything like this? Am I missing something in AIX? I appreciate
everyone's help.
Regards,
Ryan Coulter
The information included in this e-mail message, including any attachments, is intended only for the person or organization to which it is addressed. This e-mail message may contain information that is privileged or confidential. If you receive this e-mail message and are not the intended recipient or responsible for delivering the message to the intended recipient, you may not use, disseminate, distribute or copy the information included in this e-mail and any attachments. If you received this e-mail message by mistake, please reply by e-mail and destroy all copies of this message and any attachments. Thank you.
Re: [users@httpd] Help with Apache 2 problem on AIX 5.3
Posted by "William A. Rowe, Jr." <wr...@rowe-clan.net>.
Yes - for crazyness' sake, rename the file you wish to update and drop
a replacement file in it's place. See if the filesystem acknowledges
you are serving a different file.
You might also look at EnableMMAP off which can sometimes have very
similar symptoms to EnableSendfile.
Bill
Coulter, Ryan wrote:
> I spoke too soon about "EnableSendfile off" not working. Upon creating a new
> file to request, and having set the NBC back to it original size, the new
> file is not exhibiting the problem, and it would appear that it is not being
> added to the network buffer cache. The old file is still cached somehow, and
> I will have to address that problem when necessary (a server reboot at the
> very least, should resolve it).
>
> So, Apache 2 on AIX 5.3 seems to require the "EnableSendfile off" directive,
> and this should be done during the initial configuration, prior to starting
> Apache the first time.
>
> Does anyone have anything else to add?
>
> Thanks again,
> Ryan
>
>
>> From: "Coulter, Ryan" <rc...@healtheast.org>
>> Reply-To: <us...@httpd.apache.org>
>> Date: Mon, 27 Aug 2007 12:03:45 -0500
>> To: <us...@httpd.apache.org>
>> Conversation: [users@httpd] Help with Apache 2 problem on AIX 5.3
>> Subject: Re: [users@httpd] Help with Apache 2 problem on AIX 5.3
>>
>> Thank you, Eric. I had tried this in my experiments as well, without much
>> luck. However, your comment led me to a page
>> (http://publib.boulder.ibm.com/httpserv/ihsdiag/questions.html) which
>> described the network buffer cache in AIX and its association with AIX's
>> send_file routine. What is baffling me now is that setting "EnableSendfile
>> off" does nothing to alleviate the problem, but if I set the network buffer
>> cache size to 0 (no -o nbc_limit=0), the problem goes away. I consequently
>> tried setting it to 0, setting "EnableSendfile off", restarting Apache and
>> then setting nbc_limit back to its previous setting. The problem returned,
>> even with EnableSendfile turned off. As long as the network buffer cache is
>> set to 0, I don't have any problems.
>>
>> So, at least I now know what seems to be the general source of the problem,
>> but does anyone know how to correct the behavior of EnableSendfile?
>> According to the page referenced above for IHS, this directive should
>> prevent Apache from using send_file and consequently prevent any static file
>> from being added to the network buffer cache. But that doesn't seem to be
>> the case in my experience today.
>>
>> Any other thoughts?
>>
>> Ryan Coulter
>>
>>
>>> From: Eric Covener <co...@gmail.com>
>>> Reply-To: <us...@httpd.apache.org>
>>> Date: Mon, 27 Aug 2007 11:41:27 -0400
>>> To: <us...@httpd.apache.org>
>>> Subject: Re: [users@httpd] Help with Apache 2 problem on AIX 5.3
>>>
>>> On 8/27/07, Coulter, Ryan <rc...@healtheast.org> wrote:
>>>> (My apologies for sending this earlier with no subject.)
>>>>
>>>> Hello. I am stumped by a problem I'm having with Apache 2 and IHS 2 on AIX
>>>> 5.3. I have tried this scenario with both a custom compiled Apache 2.2.4 as
>>>> well as IHS 2.0.47. In both cases, the behavior is identical. Using Apache
>>>> 1.3, I don't have the problem. I have been researching the problem for
>>>> several days, but can not find any issue that describes the behavior I'm
>>>> seeing. The problem is as follows:
>>>>
>>>> I request index.html from the webserver and receive it properly in my
>>>> browser. I then log onto the server, edit the file with vi, save it and
>>>> exit. Then I return to my browser and request index.html again and it
>>>> appears as though nothing has changed. My edit does not show up. Sometimes,
>>>> after making an edit, I try to open the page in my browser and receive a
>>>> message that the browser couldn't reach the server.
>>> Try disabling sendfile (EnableSendfile off) or asking AIX support what
>>> it takes (apar-wise) to get AIX to recognize a change in the
>>> filesystem when sendfile is enabled.
>>>
>>> --
>>> Eric Covener
>>> covener@gmail.com
>>>
>>> ---------------------------------------------------------------------
>>> The official User-To-User support forum of the Apache HTTP Server Project.
>>> See <URL:http://httpd.apache.org/userslist.html> for more info.
>>> To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
>>> " from the digest: users-digest-unsubscribe@httpd.apache.org
>>> For additional commands, e-mail: users-help@httpd.apache.org
>>>
>>
>>
>> The information included in this e-mail message, including any attachments, is
>> intended only for the person or organization to which it is addressed. This
>> e-mail message may contain information that is privileged or confidential. If
>> you receive this e-mail message and are not the intended recipient or
>> responsible for delivering the message to the intended recipient, you may not
>> use, disseminate, distribute or copy the information included in this e-mail
>> and any attachments. If you received this e-mail message by mistake, please
>> reply by e-mail and destroy all copies of this message and any attachments.
>> Thank you.
>>
>> ---------------------------------------------------------------------
>> The official User-To-User support forum of the Apache HTTP Server Project.
>> See <URL:http://httpd.apache.org/userslist.html> for more info.
>> To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
>> " from the digest: users-digest-unsubscribe@httpd.apache.org
>> For additional commands, e-mail: users-help@httpd.apache.org
>>
>
>
>
> The information included in this e-mail message, including any attachments, is intended only for the person or organization to which it is addressed. This e-mail message may contain information that is privileged or confidential. If you receive this e-mail message and are not the intended recipient or responsible for delivering the message to the intended recipient, you may not use, disseminate, distribute or copy the information included in this e-mail and any attachments. If you received this e-mail message by mistake, please reply by e-mail and destroy all copies of this message and any attachments. Thank you.
>
> ---------------------------------------------------------------------
> The official User-To-User support forum of the Apache HTTP Server Project.
> See <URL:http://httpd.apache.org/userslist.html> for more info.
> To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
> " from the digest: users-digest-unsubscribe@httpd.apache.org
> For additional commands, e-mail: users-help@httpd.apache.org
>
>
>
---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
" from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org
Re: [users@httpd] Help with Apache 2 problem on AIX 5.3
Posted by "Coulter, Ryan" <rc...@healtheast.org>.
I spoke too soon about "EnableSendfile off" not working. Upon creating a new
file to request, and having set the NBC back to it original size, the new
file is not exhibiting the problem, and it would appear that it is not being
added to the network buffer cache. The old file is still cached somehow, and
I will have to address that problem when necessary (a server reboot at the
very least, should resolve it).
So, Apache 2 on AIX 5.3 seems to require the "EnableSendfile off" directive,
and this should be done during the initial configuration, prior to starting
Apache the first time.
Does anyone have anything else to add?
Thanks again,
Ryan
> From: "Coulter, Ryan" <rc...@healtheast.org>
> Reply-To: <us...@httpd.apache.org>
> Date: Mon, 27 Aug 2007 12:03:45 -0500
> To: <us...@httpd.apache.org>
> Conversation: [users@httpd] Help with Apache 2 problem on AIX 5.3
> Subject: Re: [users@httpd] Help with Apache 2 problem on AIX 5.3
>
> Thank you, Eric. I had tried this in my experiments as well, without much
> luck. However, your comment led me to a page
> (http://publib.boulder.ibm.com/httpserv/ihsdiag/questions.html) which
> described the network buffer cache in AIX and its association with AIX's
> send_file routine. What is baffling me now is that setting "EnableSendfile
> off" does nothing to alleviate the problem, but if I set the network buffer
> cache size to 0 (no -o nbc_limit=0), the problem goes away. I consequently
> tried setting it to 0, setting "EnableSendfile off", restarting Apache and
> then setting nbc_limit back to its previous setting. The problem returned,
> even with EnableSendfile turned off. As long as the network buffer cache is
> set to 0, I don't have any problems.
>
> So, at least I now know what seems to be the general source of the problem,
> but does anyone know how to correct the behavior of EnableSendfile?
> According to the page referenced above for IHS, this directive should
> prevent Apache from using send_file and consequently prevent any static file
> from being added to the network buffer cache. But that doesn't seem to be
> the case in my experience today.
>
> Any other thoughts?
>
> Ryan Coulter
>
>
>> From: Eric Covener <co...@gmail.com>
>> Reply-To: <us...@httpd.apache.org>
>> Date: Mon, 27 Aug 2007 11:41:27 -0400
>> To: <us...@httpd.apache.org>
>> Subject: Re: [users@httpd] Help with Apache 2 problem on AIX 5.3
>>
>> On 8/27/07, Coulter, Ryan <rc...@healtheast.org> wrote:
>>>
>>> (My apologies for sending this earlier with no subject.)
>>>
>>> Hello. I am stumped by a problem I'm having with Apache 2 and IHS 2 on AIX
>>> 5.3. I have tried this scenario with both a custom compiled Apache 2.2.4 as
>>> well as IHS 2.0.47. In both cases, the behavior is identical. Using Apache
>>> 1.3, I don't have the problem. I have been researching the problem for
>>> several days, but can not find any issue that describes the behavior I'm
>>> seeing. The problem is as follows:
>>>
>>> I request index.html from the webserver and receive it properly in my
>>> browser. I then log onto the server, edit the file with vi, save it and
>>> exit. Then I return to my browser and request index.html again and it
>>> appears as though nothing has changed. My edit does not show up. Sometimes,
>>> after making an edit, I try to open the page in my browser and receive a
>>> message that the browser couldn't reach the server.
>>
>> Try disabling sendfile (EnableSendfile off) or asking AIX support what
>> it takes (apar-wise) to get AIX to recognize a change in the
>> filesystem when sendfile is enabled.
>>
>> --
>> Eric Covener
>> covener@gmail.com
>>
>> ---------------------------------------------------------------------
>> The official User-To-User support forum of the Apache HTTP Server Project.
>> See <URL:http://httpd.apache.org/userslist.html> for more info.
>> To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
>> " from the digest: users-digest-unsubscribe@httpd.apache.org
>> For additional commands, e-mail: users-help@httpd.apache.org
>>
>
>
>
> The information included in this e-mail message, including any attachments, is
> intended only for the person or organization to which it is addressed. This
> e-mail message may contain information that is privileged or confidential. If
> you receive this e-mail message and are not the intended recipient or
> responsible for delivering the message to the intended recipient, you may not
> use, disseminate, distribute or copy the information included in this e-mail
> and any attachments. If you received this e-mail message by mistake, please
> reply by e-mail and destroy all copies of this message and any attachments.
> Thank you.
>
> ---------------------------------------------------------------------
> The official User-To-User support forum of the Apache HTTP Server Project.
> See <URL:http://httpd.apache.org/userslist.html> for more info.
> To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
> " from the digest: users-digest-unsubscribe@httpd.apache.org
> For additional commands, e-mail: users-help@httpd.apache.org
>
The information included in this e-mail message, including any attachments, is intended only for the person or organization to which it is addressed. This e-mail message may contain information that is privileged or confidential. If you receive this e-mail message and are not the intended recipient or responsible for delivering the message to the intended recipient, you may not use, disseminate, distribute or copy the information included in this e-mail and any attachments. If you received this e-mail message by mistake, please reply by e-mail and destroy all copies of this message and any attachments. Thank you.
---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
" from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org
Re: [users@httpd] Help with Apache 2 problem on AIX 5.3
Posted by "Coulter, Ryan" <rc...@healtheast.org>.
Thank you, Eric. I had tried this in my experiments as well, without much
luck. However, your comment led me to a page
(http://publib.boulder.ibm.com/httpserv/ihsdiag/questions.html) which
described the network buffer cache in AIX and its association with AIX's
send_file routine. What is baffling me now is that setting "EnableSendfile
off" does nothing to alleviate the problem, but if I set the network buffer
cache size to 0 (no -o nbc_limit=0), the problem goes away. I consequently
tried setting it to 0, setting "EnableSendfile off", restarting Apache and
then setting nbc_limit back to its previous setting. The problem returned,
even with EnableSendfile turned off. As long as the network buffer cache is
set to 0, I don't have any problems.
So, at least I now know what seems to be the general source of the problem,
but does anyone know how to correct the behavior of EnableSendfile?
According to the page referenced above for IHS, this directive should
prevent Apache from using send_file and consequently prevent any static file
from being added to the network buffer cache. But that doesn't seem to be
the case in my experience today.
Any other thoughts?
Ryan Coulter
> From: Eric Covener <co...@gmail.com>
> Reply-To: <us...@httpd.apache.org>
> Date: Mon, 27 Aug 2007 11:41:27 -0400
> To: <us...@httpd.apache.org>
> Subject: Re: [users@httpd] Help with Apache 2 problem on AIX 5.3
>
> On 8/27/07, Coulter, Ryan <rc...@healtheast.org> wrote:
>>
>> (My apologies for sending this earlier with no subject.)
>>
>> Hello. I am stumped by a problem I'm having with Apache 2 and IHS 2 on AIX
>> 5.3. I have tried this scenario with both a custom compiled Apache 2.2.4 as
>> well as IHS 2.0.47. In both cases, the behavior is identical. Using Apache
>> 1.3, I don't have the problem. I have been researching the problem for
>> several days, but can not find any issue that describes the behavior I'm
>> seeing. The problem is as follows:
>>
>> I request index.html from the webserver and receive it properly in my
>> browser. I then log onto the server, edit the file with vi, save it and
>> exit. Then I return to my browser and request index.html again and it
>> appears as though nothing has changed. My edit does not show up. Sometimes,
>> after making an edit, I try to open the page in my browser and receive a
>> message that the browser couldn't reach the server.
>
> Try disabling sendfile (EnableSendfile off) or asking AIX support what
> it takes (apar-wise) to get AIX to recognize a change in the
> filesystem when sendfile is enabled.
>
> --
> Eric Covener
> covener@gmail.com
>
> ---------------------------------------------------------------------
> The official User-To-User support forum of the Apache HTTP Server Project.
> See <URL:http://httpd.apache.org/userslist.html> for more info.
> To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
> " from the digest: users-digest-unsubscribe@httpd.apache.org
> For additional commands, e-mail: users-help@httpd.apache.org
>
The information included in this e-mail message, including any attachments, is intended only for the person or organization to which it is addressed. This e-mail message may contain information that is privileged or confidential. If you receive this e-mail message and are not the intended recipient or responsible for delivering the message to the intended recipient, you may not use, disseminate, distribute or copy the information included in this e-mail and any attachments. If you received this e-mail message by mistake, please reply by e-mail and destroy all copies of this message and any attachments. Thank you.
---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
" from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org
Re: [users@httpd] Help with Apache 2 problem on AIX 5.3
Posted by Eric Covener <co...@gmail.com>.
On 8/27/07, Coulter, Ryan <rc...@healtheast.org> wrote:
>
> (My apologies for sending this earlier with no subject.)
>
> Hello. I am stumped by a problem I'm having with Apache 2 and IHS 2 on AIX
> 5.3. I have tried this scenario with both a custom compiled Apache 2.2.4 as
> well as IHS 2.0.47. In both cases, the behavior is identical. Using Apache
> 1.3, I don't have the problem. I have been researching the problem for
> several days, but can not find any issue that describes the behavior I'm
> seeing. The problem is as follows:
>
> I request index.html from the webserver and receive it properly in my
> browser. I then log onto the server, edit the file with vi, save it and
> exit. Then I return to my browser and request index.html again and it
> appears as though nothing has changed. My edit does not show up. Sometimes,
> after making an edit, I try to open the page in my browser and receive a
> message that the browser couldn't reach the server.
Try disabling sendfile (EnableSendfile off) or asking AIX support what
it takes (apar-wise) to get AIX to recognize a change in the
filesystem when sendfile is enabled.
--
Eric Covener
covener@gmail.com
---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
" from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org