[squid-users] ICP and HTCP and StoreID

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 - 16:23:37 MST