I keep getting http 502 errors when accessing the squeak wiki from work. Is anyone else experiencing problems?
full error text looks like this Proxy Error The proxy server received an invalid response from an upstream server. The proxy server could not handle the request GET /. Reason: Error reading from remote server |
2007/1/8, Alan Capewell <[hidden email]>:
> > I keep getting http 502 errors when accessing the squeak wiki from work. Is > anyone else experiencing problems? > > full error text looks like this > > Proxy Error > The proxy server received an invalid response from an upstream server. > The proxy server could not handle the request GET /. > > Reason: Error reading from remote server 502 in general means the image is down. But wiki.squeak.org works for me. Philippe |
In reply to this post by Alan Capewell-3
On Mon, Jan 08, 2007 at 10:07:36AM -0800, Alan Capewell wrote:
> I keep getting http 502 errors when accessing the squeak wiki from work. Is > anyone else experiencing problems? > > full error text looks like this > > Proxy Error > The proxy server received an invalid response from an upstream server. > The proxy server could not handle the request GET /. > > Reason: Error reading from remote server I get the same error. |
Hi Alan and Pierce,
The same error response occurs while trying from abdn.ac.uk network which uses an internal Proxy Server. I believe the error is generated by that proxy server since I don't experience any such problem on my current direct connection. Can you both confirm being behind any proxy servers? Filip On 09/01/07, Pierce Ng <[hidden email]> wrote: > On Mon, Jan 08, 2007 at 10:07:36AM -0800, Alan Capewell wrote: > > I keep getting http 502 errors when accessing the squeak wiki from work. Is > > anyone else experiencing problems? > > > > full error text looks like this > > > > Proxy Error > > The proxy server received an invalid response from an upstream server. > > The proxy server could not handle the request GET /. > > > > Reason: Error reading from remote server > > I get the same error. > > > > |
I can confirm that the error should be related to an issue with beeing
behind a proxy server. When I use Squid I get the same error but it works when I use a direct connection. Franz Josef Filip Stadnik schrieb: > Hi Alan and Pierce, > > The same error response occurs while trying from abdn.ac.uk network > which uses an internal Proxy Server. I believe the error is generated > by that proxy server since I don't experience any such problem on my > current direct connection. > > Can you both confirm being behind any proxy servers? > > Filip > > > On 09/01/07, Pierce Ng <[hidden email]> wrote: >> On Mon, Jan 08, 2007 at 10:07:36AM -0800, Alan Capewell wrote: >> > I keep getting http 502 errors when accessing the squeak wiki from >> work. Is >> > anyone else experiencing problems? >> > >> > full error text looks like this >> > >> > Proxy Error >> > The proxy server received an invalid response from an upstream server. >> > The proxy server could not handle the request GET /. >> > >> > Reason: Error reading from remote server >> >> I get the same error. >> >> >> >> > |
In reply to this post by Filip Stadnik
On Tue, Jan 09, 2007 at 02:25:48PM +0000, Filip Stadnik wrote:
> Can you both confirm being behind any proxy servers? Looks like my ISP's transparent caching proxy is the cause. I used a public wifi which goes thru another ISP and can get to the site... - Pierce |
"Pierce Ng" <[hidden email]> wrote:
> On Tue, Jan 09, 2007 at 02:25:48PM +0000, Filip Stadnik wrote: > > Can you both confirm being behind any proxy servers? > > Looks like my ISP's transparent caching proxy is the cause. I used a public > wifi which goes thru another ISP and can get to the site... Does your ISP use NetCache, perchance? This is what an attempt from my machine ("telnet wiki.squeak.org 80") returns (as mutilated by an 80 column limit): GET / HTTP/1.1 Host: wiki.squeak.org HTTP/1.1 502 Proxy Error Date: Wed, 10 Jan 2007 14:59:51 GMT Content-Length: 379 Content-Type: text/html; charset=iso-8859-1 Via: 1.1 rba-cache2 (NetCache NetApp/6.0.4P1D6), 1.1 cbs-cache1 (NetCache NetApp /6.0.4P1) <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <html><head> <title>502 Proxy E rror</title> </head><body> <h1>Proxy Error</h1> <p>The proxy server received an inv alid response from an upstream server.<br /> The proxy server could not handle the request <em><a href="/">GET /</a></em >.<p> Reason: <strong>Error reading from remote server</strong></p></p> </body></h tml> Searching for the name/version in the Via header I found a reference to http://www.lagado.com/proxy-test, which neatly reveals all the proxies in your path. frank |
On Wed, Jan 10, 2007 at 05:03:48PM +0200, Frank Shearar wrote:
> "Pierce Ng" <[hidden email]> wrote: > > Looks like my ISP's transparent caching proxy is the cause. > > Does your ISP use NetCache, perchance? > > This is what an attempt from my machine ("telnet wiki.squeak.org 80") > returns (as mutilated by an 80 column limit): > > GET / HTTP/1.1 > Host: wiki.squeak.org I only get this: Trying 85.10.195.197... Connected to box2.squeakfoundation.org. Escape character is '^]'. GET / HTTP/1.1 Host: wiki.squeak.org Connection closed by foreign host. > Searching for the name/version in the Via header I found a reference to > http://www.lagado.com/proxy-test, which neatly reveals all the proxies in > your path. Cool! According to this site, my request "appears to have come via a proxy." There is one "X-BlueCoat-Via" header and two other X-Forwarded-For headers, so looks like there is a BlueCoat proxy somewhere in there... - Pierce |
Here is my situtation for last 3 days:
1) 9/1 - everything OK. 2) 10/1 - 502 Proxy Error all the day. The proxy test revealed a transparent proxy "glfd-cache-8.server.ntli.net" (62.252.0.11) in my way. 3) 11/1 - everything OK. The proxy test shows no proxy in my way as the first day. After manually setting the very same proxy in browser to simulate yesterday's behaviour all still works just fine for me. To sum up: 1) My ISP - virgin.net juggles with me every day :). 2) The malfunctioning proxy instance was either: - changed for a different one - reconfigured - or cured spontaneously after some delay (i.e. any "bad" record expired) Being out of trap, I am currently unable to further investigate the problem. Sorry :(. Cheers, Filip On 10/01/07, Pierce Ng <[hidden email]> wrote: > On Wed, Jan 10, 2007 at 05:03:48PM +0200, Frank Shearar wrote: > > "Pierce Ng" <[hidden email]> wrote: > > > Looks like my ISP's transparent caching proxy is the cause. > > > > Does your ISP use NetCache, perchance? > > > > This is what an attempt from my machine ("telnet wiki.squeak.org 80") > > returns (as mutilated by an 80 column limit): > > > > GET / HTTP/1.1 > > Host: wiki.squeak.org > > I only get this: > > Trying 85.10.195.197... > Connected to box2.squeakfoundation.org. > Escape character is '^]'. > GET / HTTP/1.1 > Host: wiki.squeak.org > > Connection closed by foreign host. > > > Searching for the name/version in the Via header I found a reference to > > http://www.lagado.com/proxy-test, which neatly reveals all the proxies in > > your path. > > Cool! According to this site, my request "appears to have come via a > proxy." There is one "X-BlueCoat-Via" header and two other X-Forwarded-For > headers, so looks like there is a BlueCoat proxy somewhere in there... > > - Pierce > > > |
In reply to this post by Filip Stadnik
Hi Filip
Apologies for not responding earlier. I am running from behind a proxy in the office (squid/2.6.STABLE4). I too have no problems accessing from home. I have tried to access through a different proxy and get the same problem whereas by-passing the proxy everything works fine. Sadly by-passing is not an option in the office. Does anyone know what version of Comanche the wiki is using or if it is fronted by Apache. I never had any problems accessing the old wiki via the proxy
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On Tue, 2007-01-16 at 05:24 -0800, Alan Capewell wrote:
> Does anyone know what version of Comanche the wiki is using or if it is > fronted by Apache. I never had any problems accessing the old wiki via the > proxy I don't have the answer to all of these questions but my understanding is that the wiki was moved wholesale. The image and files were simply copied. It is the same version of everything, including even the vm I believe. It is hosted behind Apache, 2.0.54 to be precise, and proxied by it. I'm not certain how it was hosted at GaTech. What has of course changed is the hostname (IP address) and I suspect the problem is that your proxy is troubled by that somehow. Can you access any of the other sites on that server? http://www.squeak.org/ http://lists.squeakfoundation.org/ Either way I suspect you are going to have to get some input from your proxy administrator to sort this out. Ken P.S. You might want to confirm that you get the same IP address for wiki.squeak.org and box2.squeakfoundation.org, just in case. signature.asc (196 bytes) Download Attachment |
>
> Either way I suspect you are going to have to get some input from your > proxy administrator to sort this out. > > Ken > > P.S. You might want to confirm that you get the same IP address for > wiki.squeak.org and box2.squeakfoundation.org, just in case. > I also see this happening - I use Squid at home as a transparent proxy, when I disable the proxy there's no problem. Here's the communication between squid and wiki.squeak.org (captured via tcpdump, and interpreted by wireshark) --- GET / HTTP/1.0 Host: wiki.squeak.org User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.1) Gecko/20060601 Firefox/2.0.0.1 (Ubuntu-edgy) Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Pragma: no-cache Via: 1.1 titanic.cumulo-nimbus:3128 (squid/2.5.STABLE14) X-Forwarded-For: unknown Cache-Control: no-cache, max-age=259200 Connection: keep-alive HTTP/1.1 502 Proxy Error Date: Tue, 16 Jan 2007 20:32:41 GMT Content-Length: 379 Connection: close Content-Type: text/html; charset=iso-8859-1 <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <html><head> <title>502 Proxy Error</title> </head><body> <h1>Proxy Error</h1> <p>The proxy server received an invalid response from an upstream server.<br /> The proxy server could not handle the request <em><a href="/">GET /</a></em>.<p> Reason: <strong>Error reading from remote server</strong></p></p> </body></html> --- If it helps, I can supply the raw tcpdump as well. I can also confirm that it's correctly connecting to box2.squeakfoundation.org and that both box2 and wiki.squeak.org resolve to the same IP address (85.10.195.197) Let me know if you need more information. Regards, Stuart. |
Thanks for the information. This helped me track down a possible cause
and I have upgraded apache2 hopefully fixing it. I would appreciate it if you could check whether or not you continue to see the same behavior or whether it now works for you. Ken On Wed, 2007-01-17 at 07:46 +1100, Stuart Herring wrote: > > > > Either way I suspect you are going to have to get some input from your > > proxy administrator to sort this out. > > > > Ken > > > > P.S. You might want to confirm that you get the same IP address for > > wiki.squeak.org and box2.squeakfoundation.org, just in case. > > > > I also see this happening - I use Squid at home as a transparent > proxy, when I disable the proxy there's no problem. > Here's the communication between squid and wiki.squeak.org (captured > via tcpdump, and interpreted by wireshark) > --- > GET / HTTP/1.0 > > Host: wiki.squeak.org > > User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.1) > Gecko/20060601 Firefox/2.0.0.1 (Ubuntu-edgy) > > Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5 > > Accept-Language: en-us,en;q=0.5 > > Accept-Encoding: gzip,deflate > > Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 > > Pragma: no-cache > > Via: 1.1 titanic.cumulo-nimbus:3128 (squid/2.5.STABLE14) > > X-Forwarded-For: unknown > > Cache-Control: no-cache, max-age=259200 > > Connection: keep-alive > > > > HTTP/1.1 502 Proxy Error > > Date: Tue, 16 Jan 2007 20:32:41 GMT > > Content-Length: 379 > > Connection: close > > Content-Type: text/html; charset=iso-8859-1 > > > > <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> > <html><head> > <title>502 Proxy Error</title> > </head><body> > <h1>Proxy Error</h1> > <p>The proxy server received an invalid > > response from an upstream server.<br /> > > The proxy server could not handle the request <em><a > href="/">GET /</a></em>.<p> > Reason: <strong>Error reading from remote server</strong></p></p> > </body></html> > --- > If it helps, I can supply the raw tcpdump as well. > I can also confirm that it's correctly connecting to > box2.squeakfoundation.org and that both box2 and wiki.squeak.org > resolve to the same IP address (85.10.195.197) > > Let me know if you need more information. > > Regards, > Stuart. > > signature.asc (196 bytes) Download Attachment |
On 1/17/07, Ken Causey <[hidden email]> wrote:
> Thanks for the information. This helped me track down a possible cause > and I have upgraded apache2 hopefully fixing it. I would appreciate it > if you could check whether or not you continue to see the same behavior > or whether it now works for you. Unfortunately it looks like it's still the same. Regards, Stuart. |
I still have the same problem too - Unfortunately unlike Stuart I don't have access to the office proxy logs Thanks for looking into this Alan |
In reply to this post by Stuart Herring-2
On Wed, Jan 17, 2007 at 06:18:58PM +1100, Stuart Herring wrote:
> On 1/17/07, Ken Causey <[hidden email]> wrote: > >Thanks for the information. This helped me track down a possible cause > >and I have upgraded apache2 hopefully fixing it. I would appreciate it > >if you could check whether or not you continue to see the same behavior > >or whether it now works for you. > > Unfortunately it looks like it's still the same. I don't know if it's related to this discussion or not, but I notice that I cannot upload a file to the swiki. The response page shows this: Proxy Error The proxy server received an invalid response from an upstream server. The proxy server could not handle the request GET /squeak/708.upload. Reason: Error reading from remote server |
This is yet another problem. Thanks for the report. I am able to
reproduce this and I suspect it is simply that we have missed something regarding the Apache configuration. Jochen: Any suggestions? Ken P.S. Interestingly enough I get a very similar error message [Wed Jan 17 17:57:08 2007] [error] [client 74.141.66.178] proxy: error reading status line from remote server 127.0.0.1, referer: http://wiki.squeak.org/squeak/2432.upload [Wed Jan 17 17:57:08 2007] [error] [client 74.141.66.178] proxy: Error reading from remote server returned by /squeak/2432.upload, referer: http://wiki.squeak.org/squeak/2432.upload when I attempt to upload to what we are seeing regarding the complaints from those attempting to access the site from behind a proxy. So maybe this is more related than I think. However I (and I assume David) can view the pages without any trouble whereas the others are reporting (I believe) a complete inability to access the site. In my research of the initial reports I found http://issues.apache.org/bugzilla/show_bug.cgi?id=37770 which seems related. I noticed that there was a new version of Apache2 (still 2.0.54 but a new intra-Debian version) and installed it. But it seems that has had no effect. I will continue to investigate, but any help is appreciated. On Wed, 2007-01-17 at 05:59 -0500, David T. Lewis wrote: > On Wed, Jan 17, 2007 at 06:18:58PM +1100, Stuart Herring wrote: > > On 1/17/07, Ken Causey <[hidden email]> wrote: > > >Thanks for the information. This helped me track down a possible cause > > >and I have upgraded apache2 hopefully fixing it. I would appreciate it > > >if you could check whether or not you continue to see the same behavior > > >or whether it now works for you. > > > > Unfortunately it looks like it's still the same. > > I don't know if it's related to this discussion or not, but I notice that > I cannot upload a file to the swiki. The response page shows this: > > Proxy Error > > The proxy server received an invalid response from an upstream server. > The proxy server could not handle the request GET /squeak/708.upload. > > Reason: Error reading from remote server > > > signature.asc (196 bytes) Download Attachment |
David: Please try again, I think I have fixed the problem you and I saw.
Stuart: Could you try accessing the site again from behind your proxy and report back? Thanks. It turns out that maybe I made this out to be harder than it was. The apache documentation regarding the proxy module mentions "For circumstances where you have a application server which doesn't implement keepalives or HTTP/1.1 properly, there are 2 environment variables which when set send a HTTP/1.0 with no keepalive." So I set them SetEnv force-proxy-request-1.0 1 SetEnv proxy-nokeepalive 1 for wiki.squeak.org and this seems to have taken care of at least one aspect of this issue, and I hope the other as well. Ken signature.asc (196 bytes) Download Attachment |
Hey Ken,
I think you can try it yourself as well. Just setup this HTTP proxy in in your browser: glfd-cache-8.server.ntli.net, port 80 I believe this one needs no authentication. Perhaps it could help you to analyse the problem. Let me know, if it helped Cheers, Filip On 17/01/07, Ken Causey <[hidden email]> wrote: > David: Please try again, I think I have fixed the problem you and I saw. > > Stuart: Could you try accessing the site again from behind your proxy > and report back? Thanks. > > It turns out that maybe I made this out to be harder than it was. The > apache documentation regarding the proxy module mentions > > "For circumstances where you have a application server which doesn't > implement keepalives or HTTP/1.1 properly, there are 2 environment > variables which when set send a HTTP/1.0 with no keepalive." > > So I set them > > SetEnv force-proxy-request-1.0 1 > SetEnv proxy-nokeepalive 1 > > for wiki.squeak.org and this seems to have taken care of at least one > aspect of this issue, and I hope the other as well. > > Ken > > > > > > > |
Thanks for the suggestion but I think I must need either authentication
or it doesn't like my IP address because if I use that I can't get anywhere. Good idea though. Ken On Wed, 2007-01-17 at 19:02 +0000, Filip Stadnik wrote: > Hey Ken, > > I think you can try it yourself as well. Just setup this HTTP proxy in > in your browser: > glfd-cache-8.server.ntli.net, port 80 > > I believe this one needs no authentication. > > Perhaps it could help you to analyse the problem. > Let me know, if it helped > > Cheers, > > Filip signature.asc (196 bytes) Download Attachment |
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