[squid-users] 503 service unavailable on connection refused

[Alex Rousskov]

On 05/29/2017 01:03 AM, Dominic Kim wrote:

> It looks squid is retrying many times.
> And after reach maximum retry limit, it responds with 503 service
> unavailable.

> As you know maximum limit is 10 times.
> It looks that it retries 10 times within just 3 seconds.

> Are there any way to configure retry interval?

There is not -- Squid retries as fast as possible. A quality patch
adding an ACL-driven artificial retry delay and/or an exponential
backoff algorithm should be welcomed IMO.

Alex.


> 2017-05-23 1:13 GMT+09:00 Alex Rousskov:
> 
>     On 05/22/2017 03:02 AM, Dominic Kim wrote:
>     > I have tested with squid 3.3, 3.5, 4.
>     > And the behavior were same.
> 
>     When using Squid v3.5 or v4, please reproduce the problem using a single
>     HTTP transaction while collecting level-7 or higher debugging and then
>     post the corresponding (compressed) cache.log.
> 
>     http://wiki.squid-cache.org/SquidFaq/BugReporting#Debugging_a_single_transaction
>     <http://wiki.squid-cache.org/SquidFaq/BugReporting#Debugging_a_single_transaction>
> 
>     Alex.
> 
> 
>     > 2017-05-22 18:01 GMT+09:00 Dominic Kim:
>     >
>     >     When I connect to a target server via squid, if server does not
>     >     exist, I get "No route to host" error.
>     >     And if server exist, but port is not opened yet, I get "Connection
>     >     refused" error.
>     >
>     >     As per the definition of "connect_retries" option, it should retry
>     >     when connection attempt failed.
>     >     (reference: http://www.squid-cache.org/Doc/config/connect_retries/
>     <http://www.squid-cache.org/Doc/config/connect_retries/>
>     >     <http://www.squid-cache.org/Doc/config/connect_retries/
>     <http://www.squid-cache.org/Doc/config/connect_retries/>>)
>     >
>     >     IMHO, in both the cases, connection attempts failed and it is
>     >     supposed to retry.
>     >     However, if I enable this feature, it only retries on "No route to
>     >     host" error.
>     >     In case of "Connection refused", I am getting 503 service
>     >     unavailable error immediately.
>     >
>     >     Are there anyway to fix this behavior?
>     >     Kindly help me.