Re: Warning "Revalidation failed" and TCP_REFRESH_UNMODIFIED/200

 On Wed, 3 Aug 2011 18:38:11 +0300, Tsachi wrote:
> Hey,
> I am testing Squid 3.2.0.5,

 Please keep up with the beta releases. Current "most stable" is
 3.2.0.8, followed closely by 3.2.0.10.

> Can you please comment if these are normal or not:
>
> Client is sending a GET request for a file (No IMS in the request),
> Squid has the file but it is Stale.
> Squid sends an IMS request to the HTTP server and get a 304 reply
> (Not modified)
> Then Squid sends the file to the Client with HTTP 200 and in the
> access.log I see this:
>
> 1312373066.721 20 10.102.151.51 TCP_REFRESH_UNMODIFIED/200 10955
> GET http://10.102.150.90/Mydir/50.docx - HIER_DIRECT/10.102.150.90
>
> application/vnd.openxmlformats-officedocument.wordprocessingml.document
>
> Should the line in access.log be TCP_REFRESH_UNMODIFIED/304 ?

 No.

 If the client requested an object with no ETag and Squid performed IMS
 with an ETag. The client would need to be sent an updated version with
 header changes including ETag and body in case there was some hidden
 change between Etag and no-ETag. In that case TCP_REFRESH_UNMODIFIED/200
 is correct.

 From the below I see that both are incorrect for what happened to you.

 FWIW: in the latest releases we are starting to make distinction
 between client-squid and squid-server connection details in the logging
 now to clarify this type of situation. Especially since adaptation can
 change things radically between them.

>
> Looking in the replay header we see these:
> Warning: 110 squid/3.2.0.5 "Response is stale"
> Warning: 111 squid/3.2.0.5 "Revalidation failed" <<<<<<<< Why this ?

 Server replied with a 5xx status code.

 Bug the first: seems to be missing a timestamp indicating when that
 happened, so can be removed when obsolete.

> X-Cache: HIT from SquidBeta
>
> Here is the request and the replay client side:
>
> GET /Mydir/50.docx HTTP/1.1
> Accept: */*
> Accept-Encoding: gzip, deflate
> User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1;
> GTB7.1; InfoPath.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR
> 3.0.4506.2152; .NET CLR 3.5.30729)
> Host: 10.102.150.90
> Connection: Keep-Alive
>
> HTTP/1.1 200 OK
> Content-Type:
>
> application/vnd.openxmlformats-officedocument.wordprocessingml.document
> Last-Modified: Wed, 03 Aug 2011 10:28:27 GMT
> Content-Length: 10442
> Accept-Ranges: bytes
> ETag: "2146c914c851cc1:0"
> Server: Microsoft-IIS/7.0
> X-Powered-By: ASP.NET
> Date: Wed, 03 Aug 2011 10:50:47 GMT
> Age: 3473
> Warning: 110 squid/3.2.0.5 "Response is stale"
> Warning: 111 squid/3.2.0.5 "Revalidation failed"
> X-Cache: HIT from SquidBeta
> Via: 1.1 SquidBeta (squid/3.2.0.5)
> Connection: keep-alive

 Bug the second: should log TCP_REFRESH_FAIL/200 for revalidate failure
 with server but 200 sent to client anyway.

 Please check the latest beta for these two bugs before continuing.

 Amos
Received on Wed Aug 03 2011 - 23:08:40 MDT