Please explain this 502 Bad Gateway error

hi,

I am using version 0.5.34.

I am testing nginx as a proxy server + static file server for my test
site
deployed on jetty.

Can you please explain the error mentioned here.

Error Log Entry : [2007/12/27 10:44:07 [error] 2625#0: *7 connect()
failed
(111: Connection refused) while connecting to upstream, client:
192.168.0.234, server: localhost, request: “GET
/KdocProj/dboard.html?_dc=1198726407859 HTTP/1.0”, upstream: "
http://192.168.0.241:8080/KdocProj/dboard.html?_dc=1198726407859", host:
"
192.168.0.241:8000"]

Thanks,
Rakesh.

On Thu, Dec 27, 2007 at 08:50:47PM +0530, just starting wrote:

192.168.0.241:8000"]
man errno:

 61 ECONNREFUSED Connection refused.  No connection could be made 

because
the target machine actively refused it. This usually
results
from trying to connect to a service that is inactive on the
for-
eign host.

The “Connection refused” usually means that backend does not listen
on 192.168.0.241:8080 or its listen queue is full: it can not handle all
requests.

Hi,

On Don 27.12.2007 20:50, just starting wrote:

(111: Connection refused) while connecting to upstream, client:
Which clearly say:

the connection to 192.168.0.241 on port 8080 with protocol http was not
successful.

What is in the jetty log?
Are you able to reach jetty with curl, curl -v
http://192.168.0.241:8080/ ?
Is a FW between nginx & jetty?

192.168.0.234, server: localhost, request: “GET
/KdocProj/dboard.html?_dc=1198726407859 HTTP/1.0”, upstream: "
http://192.168.0.241:8080/KdocProj/dboard.html?_dc=1198726407859", host: "
192.168.0.241:8000"]

Cheers

Aleks

hi,

First of all my sincere thanks.

Error Log Entry : [2007/12/27 10:44:07 [error] 2625#0: *7 connect()
failed (111: Connection refused) while connecting to upstream, client:
192.168.0.234, server: localhost, request:
“GET /KdocProj/dboard.html?_dc=1198726407859 HTTP/1.0”, upstream: "
http://192.168.0.241:8080/KdocProj/dboard.html?_dc=1198726407859", host:
"
192.168.0.241:8000"]

Let me explain a few things.

The machine where I am testing the hosting is 192.168.0.241.
nginx is hosted on port 8000 and jetty on 8080 on the same machine
mentioned
above.

There is a statement in the error log like : “while connecting to
upstream,
client: 192.168.0.234,”, please note that 192.168.0.234 is the local
proxy
server for internet access. So, what i think happening here is that
nginx is
trying to access the local jetty server via proxy.

For Igor:

The “Connection refused” usually means that backend does not listen
on 192.168.0.241:8080 or its listen queue is full: it can not handle all
requests.

I am the only one testing this implementation. So, I dont think the
listen
queue is full and also I made sure that jetty is listening on port 8080.

Thanks,
Rakesh.

PS: I appreciate for your quick reply. Frankly I haven’t hoped for such
quick reply. Hope you do well in the future.

ohh…I forgot to mention that bit to you. I had it setup as 127.0.0.1
and in
that case also it was not working. Then for a change i altered it to
192.168.0.241. I will test it further and let you know how it goes.

Then it’s prbably firewall.

How is it possible if both my servers are hosted on the same machine
with ip
192.168.0.241.

Thanks
Rakesh.

On Fri, Dec 28, 2007 at 12:09:45AM +0530, just starting wrote:

ohh…I forgot to mention that bit to you. I had it setup as 127.0.0.1 and in
that case also it was not working. Then for a change i altered it to
192.168.0.241. I will test it further and let you know how it goes.

Then it’s prbably firewall.

How is it possible if both my servers are hosted on the same machine with ip
192.168.0.241.

I have no idea. The “Connection refused” is a system error, but not
nginx’s
one. This is what kernel returns to nginx.

Are you able to do on this host

telnet 192.168.0.241 8080

?

On Thu, Dec 27, 2007 at 10:36:00PM +0530, just starting wrote:

Let me explain a few things.

The machine where I am testing the hosting is 192.168.0.241.
nginx is hosted on port 8000 and jetty on 8080 on the same machine mentioned
above.

There is a statement in the error log like : “while connecting to upstream,
client: 192.168.0.234,”, please note that 192.168.0.234 is the local proxy
server for internet access. So, what i think happening here is that nginx is
trying to access the local jetty server via proxy.

The “client: 192.168.0.234” means that someone on 192.168.0.234 has
connected
to nginx and request. nginx proxies the request to 192.168.0.241:8080.

Probably you should set “proxy_pass http://127.0.0.1:8080” instead
of 192.168.0.241:8080.

For Igor:

The “Connection refused” usually means that backend does not listen
on 192.168.0.241:8080 or its listen queue is full: it can not handle all
requests.

I am the only one testing this implementation. So, I dont think the listen
queue is full and also I made sure that jetty is listening on port 8080.

Then it’s prbably firewall.

The answer is yes to the question.

Should I copy the conf file for you to have a look.

Thanks,
Paritosh.

On Fri, Dec 28, 2007 at 01:03:07AM +0530, just starting wrote:

The answer is yes to the question.

So you are able to do on this host

telnet 192.168.0.241 8080
HEAD / HTTP/1.0

Does this error appear from the very first request or after some time ?

Should I copy the conf file for you to have a look.

I do not think that this is configuration issue.