[squid-users] Re: ICP and HTCP and StoreID

Actually, it is working. I found two mistakes in my config - a typo in
cache_peer_access directive and absence of 'allow-miss' in the
cache_peer definition.

After fixing them, inter cache communication is working only with
altered URLs but this still does the job:
- If UDP is MISS the originating peer makes a TCP connection to
destination server and caches the result
- if UDP is HIT, the call is forwarded via sibling with modified URL,
but the sibling handles the request without problems

UDP HIT request example:
peer B: UDP_HIT/000 0 HTCP_TST
http://c.youtube.com.squid.internal/videoplayback/09ebf166f4892e4f.140.712704-950271
- HIER_NONE/- -
peer B: TCP_HIT/200 237948 GET
http://c.youtube.com.squid.internal/videoplayback/09ebf166f4892e4f.140.712704-950271
- HIER_NONE/- application/octet-stream
peer A: TCP_MISS/200 237948 GET
http://r2---sn-bavc5aoxu-nv4e.googlevideo.com/videoplayback? -
SIBLING_HIT/peerb application/octet-stream

UDP MISS request example:
peer B: UDP_MISS/000 0 HTCP_TST
http://c.youtube.com.squid.internal/videoplayback/09ebf166f4892e4f.140.2138112-2375679
- HIER_NONE/- -
peer A: TCP_MISS/200 237938 GET
http://r2---sn-bavc5aoxu-nv4e.googlevideo.com/videoplayback? -
HIER_DIRECT/r2---sn-bavc5aoxu-nv4e.googlevideo.com
application/octet-stream

Case closed!

On Wed, Jan 15, 2014 at 6:22 PM, Niki Gorchilov <niki_at_gorchilov.com> wrote:
> Hi All,
>
> I know, according to wiki
> (http://wiki.squid-cache.org/Features/StoreID) ICP & HTCP are not
> supported. “URL queries received from cache_peer siblings are not
> passed through StoreID helper. So the resulting store/cache lookup
> will MISS on URLs normally alterd by StoreID.”
>
> Still, in lab test show that cache peer is queried by the StoreID
> altered URL, so this part is actually working. At least in version
> 3.4.1.
>
> The real problem is, when a siblink replies with UDP_HIT, the actual
> HTTP request sent to this peer uses the altered URL, instead of the
> original one.
>
> Here's a simple example:
>
> 1. Peer A receives request for URL like
> http://r2---sn-bavc5aoxu-nv4e.googlevideo.com/videoplayback?
> 2. Peer A's StoreID helper normalizes the URL to
> http://c.youtube.com.squid.internal/videoplayback/09ebf166f4892e4f.140.950272-1187839
> 3. Peer A makes an ICP/HTCP query to Peer B for
> http://c.youtube.com.squid.internal/videoplayback/09ebf166f4892e4f.140.950272-1187839
> 4. Peer B replies with "UDP_HIT/000 0 HTCP_TST
> http://c.youtube.com.squid.internal/videoplayback/09ebf166f4892e4f.140.950272-1187839"
> 5. Peer A creates HTTP connection to Peer B and makes "GET
> http://c.youtube.com.squid.internal/videoplayback/09ebf166f4892e4f.140.950272-1187839
> HTTP/1.1"
> 6. Peer B, tries to connect to the non-existent host
> c.youtube.com.squid.internal and as a result generates HTTP 504 error.
> 7. Peer A receives "TCP_MISS/504 4181 GET
> http://c.youtube.com.squid.internal/videoplayback/09ebf166f4892e4f.140.950272-1187839
> - HIER_NONE/- text/html" and goes directly to youtube "TCP_MISS/200
> 237938 GET http://r2---sn-bavc5aoxu-nv4e.googlevideo.com/videoplayback?
> - HIER_DIRECT/r2---sn-bavc5aoxu-nv4e.googlevideo.com
> application/octet-stream"
>
> The question is how to force squid to use the original URL when making
> the TCP/HTTP connection to the peer after UDP_HIT? UDP request shall
> keep using the normalized/rewritten URL.
>
> Thank in advance for any ideas.
>
> Best,
> Niki
Received on Wed Jan 15 2014 - 22:32:10 MST