Thanks again for your answers. On my test server, I did setup 3 apaches on 127.0.0.1:[81|82|83] and 3 squids on 192.168.16.[11|12|13] Sorry, the post is a bit long... ====================================================================== Delete browser cache and start 3 squids with brand new cache... ====================================================================== ==> /var/log/squid/cache.log <== .... 2008/06/26 11:10:54| Accepting accelerated HTTP connections at 192.168.17.11, port 80, FD 11. 2008/06/26 11:10:54| Accepting ICP messages at 0.0.0.0, port 3130, FD 12. 2008/06/26 11:10:54| WCCP Disabled. 2008/06/26 11:10:54| Configuring Parent 127.0.0.1/8081/0 2008/06/26 11:10:54| Configuring Sibling 192.168.17.12/80/3130 2008/06/26 11:10:54| Configuring Sibling 192.168.17.13/80/3130 2008/06/26 11:10:54| Ready to serve requests. .... ==> /var/log/squid2/cache.log <== .... 2008/06/26 11:10:56| Accepting accelerated HTTP connections at 192.168.17.12, port 80, FD 11. 2008/06/26 11:10:56| Accepting ICP messages at 0.0.0.0, port 3130, FD 12. 2008/06/26 11:10:56| WCCP Disabled. 2008/06/26 11:10:56| Configuring Parent 127.0.0.1/8082/0 2008/06/26 11:10:56| Configuring Sibling 192.168.17.11/80/3130 2008/06/26 11:10:56| Configuring Sibling 192.168.17.13/80/3130 2008/06/26 11:10:56| Ready to serve requests. .... ==> /var/log/squid3/cache.log <== .... 2008/06/26 11:10:57| Accepting accelerated HTTP connections at 192.168.17.13, port 80, FD 11. 2008/06/26 11:10:57| Accepting ICP messages at 0.0.0.0, port 3130, FD 12. 2008/06/26 11:10:57| WCCP Disabled. 2008/06/26 11:10:57| Configuring Parent 127.0.0.1/8083/0 2008/06/26 11:10:57| Configuring Sibling 192.168.17.11/80/3130 2008/06/26 11:10:57| Configuring Sibling 192.168.17.12/80/3130 2008/06/26 11:10:57| Ready to serve requests. .... ====================================================================== Access squid1... ====================================================================== ==> /var/log/squid1/access.log <== 1214491088.291 1001 192.168.17.11 TCP_MISS/200 2329 GET http://192.168.17.11/ - TIMEOUT_FIRST_UP_PARENT/127.0.0.1 text/html 1214491089.292 1000 192.168.17.11 TCP_MISS/200 4378 GET http://192.168.17.11/img/apache_header.gif - TIMEOUT_FIRST_UP_PARENT/127.0.0.1 image/gif ==> /var/log/httpd/apache-8081.access_log <== 127.0.0.1 - - [26/Jun/2008:16:38:08 +0200] "GET / HTTP/1.0" 200 2020 127.0.0.1 - - [26/Jun/2008:16:38:09 +0200] "GET /img/apache_header.gif HTTP/1.0" 200 4084 ==> /var/log/squid2/access.log <== 1214491087.293 0 192.168.17.12 TCP_MEM_HIT/200 373 GET internal://pc-03/squid-internal-periodic/store_digest - NONE/- application/cache-digest ==> /var/log/squid3/access.log <== 1214491086.740 0 192.168.17.12 UDP_MISS/000 42 ICP_QUERY http://192.168.17.11/ - NONE/- - 1214491086.740 0 192.168.17.13 UDP_MISS/000 42 ICP_QUERY http://192.168.17.11/ - NONE/- - 1214491087.740 0 192.168.17.12 UDP_MISS/000 63 ICP_QUERY http://192.168.17.11/img/apache_header.gif - NONE/- - 1214491087.740 0 192.168.17.13 UDP_MISS/000 63 ICP_QUERY http://192.168.17.11/img/apache_header.gif - NONE/- - 1214491147.291 0 192.168.17.13 TCP_MEM_HIT/200 373 GET internal://pc-03/squid-internal-periodic/store_digest - NONE/- application/cache-digest ====================================================================== Access squid1 again... ====================================================================== ==> /var/log/squid1/access.log <== 1214491262.555 0 192.168.17.11 TCP_REFRESH_HIT/304 189 GET http://192.168.17.11/ - FIRST_UP_PARENT/127.0.0.1 - 1214491262.936 380 192.168.17.11 TCP_REFRESH_HIT/304 189 GET http://192.168.17.11/img/apache_header.gif - FIRST_UP_PARENT/127.0.0.1 - ==> /var/log/httpd/apache-8081.access_log <== 127.0.0.1 - - [26/Jun/2008:16:41:02 +0200] "GET / HTTP/1.0" 304 - 127.0.0.1 - - [26/Jun/2008:16:41:02 +0200] "GET /img/apache_header.gif HTTP/1.0" 304 - ====================================================================== Access squid1 several times ====================================================================== ==> /var/log/squid1/access.log <== 1214491330.658 0 192.168.17.11 TCP_IMS_HIT/304 253 GET http://192.168.17.11/ - NONE/- text/html 1214491331.150 492 192.168.17.11 TCP_IMS_HIT/304 238 GET http://192.168.17.11/img/apache_header.gif - NONE/- image/gif 1214491393.377 749 192.168.17.11 TCP_IMS_HIT/304 244 GET http://192.168.17.11/ - NONE/- text/html 1214491393.556 17 192.168.17.11 TCP_IMS_HIT/304 237 GET http://192.168.17.11/img/apache_header.gif - NONE/- image/gif 1214491409.228 683 192.168.17.11 TCP_IMS_HIT/304 253 GET http://192.168.17.11/ - NONE/- text/html 1214491409.545 317 192.168.17.11 TCP_IMS_HIT/304 238 GET http://192.168.17.11/img/apache_header.gif - NONE/- image/gif ====================================================================== Access squid1 again with shift-reload ====================================================================== ==> /var/log/squid1/access.log <== 1214491556.821 224 192.168.17.11 TCP_MEM_HIT/200 2338 GET http://192.168.17.11/ - NONE/- text/html 1214491557.228 0 192.168.17.11 TCP_MEM_HIT/200 4387 GET http://192.168.17.11/img/apache_header.gif - NONE/- image/gif ====================================================================== Access squid2... ====================================================================== ==> /var/log/squid1/access.log <== 1214491626.204 0 192.168.17.11 TCP_MEM_HIT/200 372 GET internal://pc-03/squid-internal-periodic/store_digest - NONE/- application/cache-digest ==> /var/log/squid2/access.log <== 1214491626.205 2 192.168.17.12 TCP_MISS/200 2329 GET http://192.168.17.12/ - TIMEOUT_FIRST_UP_PARENT/127.0.0.1 text/html 1214491626.788 582 192.168.17.12 TCP_MISS/200 4378 GET http://192.168.17.12/img/apache_header.gif - TIMEOUT_FIRST_UP_PARENT/127.0.0.1 image/gif 1214491626.833 45 192.168.17.12 TCP_REFRESH_HIT/200 1388 GET http://192.168.17.12/favicon.ico - FIRST_UP_PARENT/127.0.0.1 text/plain ==> /var/log/squid3/access.log <== 1214491625.868 0 192.168.17.11 UDP_MISS/000 42 ICP_QUERY http://192.168.17.12/ - NONE/- - 1214491625.868 0 192.168.17.13 UDP_MISS/000 42 ICP_QUERY http://192.168.17.12/ - NONE/- - 1214491626.203 0 192.168.17.11 UDP_MISS/000 63 ICP_QUERY http://192.168.17.12/img/apache_header.gif - NONE/- - 1214491626.203 0 192.168.17.13 UDP_MISS/000 63 ICP_QUERY http://192.168.17.12/img/apache_header.gif - NONE/- - 1214491686.204 0 192.168.17.13 TCP_MEM_HIT/200 373 GET internal://pc-03/squid-internal-periodic/store_digest - NONE/- application/cache-digest ==> /var/log/httpd/apache-8082.access_log <== 127.0.0.1 - - [26/Jun/2008:16:47:06 +0200] "GET / HTTP/1.0" 200 2020 127.0.0.1 - - [26/Jun/2008:16:47:06 +0200] "GET /img/apache_header.gif HTTP/1.0" 200 4084 127.0.0.1 - - [26/Jun/2008:16:47:06 +0200] "GET /favicon.ico HTTP/1.0" 304 - ====================================================================== Access squid2 again... ====================================================================== ==> /var/log/squid2/access.log <== 1214491777.739 0 192.168.17.12 TCP_REFRESH_HIT/304 189 GET http://192.168.17.12/ - FIRST_UP_PARENT/127.0.0.1 - 1214491778.143 400 192.168.17.12 TCP_REFRESH_HIT/304 189 GET http://192.168.17.12/img/apache_header.gif - FIRST_UP_PARENT/127.0.0.1 - ==> /var/log/httpd/apache-8082.access_log <== 127.0.0.1 - - [26/Jun/2008:16:49:37 +0200] "GET / HTTP/1.0" 304 - 127.0.0.1 - - [26/Jun/2008:16:49:38 +0200] "GET /img/apache_header.gif HTTP/1.0" 304 - ====================================================================== Access squid2 again... ====================================================================== ==> /var/log/squid2/access.log <== 1214491859.081 0 192.168.17.12 TCP_IMS_HIT/304 253 GET http://192.168.17.12/ - NONE/- text/html 1214491859.331 249 192.168.17.12 TCP_IMS_HIT/304 238 GET http://192.168.17.12/img/apache_header.gif - NONE/- image/gif ====================================================================== Access squid2 again with shift-reload ====================================================================== ==> /var/log/squid2/access.log <== 1214491885.673 76 192.168.17.12 TCP_MEM_HIT/200 2339 GET http://192.168.17.12/ - NONE/- text/html 1214491885.763 90 192.168.17.12 TCP_MEM_HIT/200 4388 GET http://192.168.17.12/img/apache_header.gif - NONE/- image/gif ====================================================================== Access squid3 to be sure objects are cached, then purge the img from squid1 and access squid1... ====================================================================== ==> /var/log/squid1/access.log <== 1214492073.319 629 192.168.17.11 TCP_MEM_HIT/200 2338 GET http://192.168.17.11/ - NONE/- text/html 1214492073.408 88 192.168.17.11 TCP_MISS/200 4378 GET http://192.168.17.11/img/apache_header.gif - FIRST_UP_PARENT/127.0.0.1 image/gif ==> /var/log/httpd/apache-8081.access_log <== 127.0.0.1 - - [26/Jun/2008:16:54:33 +0200] "GET /img/apache_header.gif HTTP/1.0" 200 4084 ==> /var/log/squid3/access.log <== 1214492072.948 0 192.168.17.12 UDP_MISS/000 63 ICP_QUERY http://192.168.17.11/img/apache_header.gif - NONE/- - 1214492072.948 0 192.168.17.13 UDP_MISS/000 63 ICP_QUERY http://192.168.17.11/img/apache_header.gif - NONE/- - ====================================================================== Access squid1 to be sure objects are cached, then purge the img from squid3 and access squid3... ====================================================================== Same results as previous tests, but 1 <-> 3 Squid2 totaly ignored as sibling... ====================================================================== Access squid1,2,3 to be sure objects are cached, then purge the img from squid2 and access squid2... ====================================================================== Same results as previous tests, squid3 used as sibling but failed... At the same time, I suddenly got: ==> /var/log/squid2/cache.log <== 2008/06/26 17:05:05| Detected DEAD Sibling: squid3 2008/06/26 17:05:05| Detected DEAD Sibling: squid1 ====================================================================== So, to sumarize: Apaches work. Each squid access its own apache correctly. They all seem to exchange their digests: squid1: .... GET http://192.168.17.12/squid-internal-periodic/store_digest .... GET http://192.168.17.13/squid-internal-periodic/store_digest squid2: .... GET http://192.168.17.11/squid-internal-periodic/store_digest .... GET http://192.168.17.13/squid-internal-periodic/store_digest squid3: .... GET http://192.168.17.11/squid-internal-periodic/store_digest .... GET http://192.168.17.12/squid-internal-periodic/store_digest But, the DEAD siblings message is not good... As seen on the mailing list, I tried with icp_query_timeout 1000 in case the auto settings of the timeout are wrong... The siblings (at least squid 1 and 3) react when they are asked about a missing object, but don't send anything back, so apache is still used. Squid 2 is not very talkative... Almost there... ^_^ JD
