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@xxxxxxxxxxxxx> 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
