Web Caching\u6548\u7387\u7684\u6539\u5584\u4e3b\u8981\u8457\u91cd\u5728\uff1a
1\u63d0\u9ad8accumulative cache\u00a0hit ratio(\u6210\u529f\u5feb\u53d6\u7684\u6bd4\u7387):
\u3000\u4f7f\u7528\u8005\u53ef\u5728\u8f03\u77ed\u6642\u9593\u5167\u53d6\u5f97\u8cc7\u6599\uff0c\u800c\u4e0d\u7528\u9023\u5230\u539f\u59cb\u7db2\u8def\u53bb\u63a5\u53d6\u8cc7\u6599\uff0c\u4f7f\u5f97:
\u3000a.\u6e1b\u5c11\u4f7f\u7528\u8005\u7b49\u5f85\u7684latency(\u5ef6\u9072\u6642\u9593)
\u3000b.\u6e1b\u5c11cache miss\u7684\u767c\u751f\uff0c\u56e0\u70ba\u4e00\u4f46\u767c\u751fcache miss\u5247\u5fc5\u5b9a\u6703\u589e\u52a0latency
\u3000c.\u6e1b\u5c11\u7db2\u8def\u8ca0\u8f09\uff0c\u6e1b\u5c11\u8cc7\u6599\u5728\u91cd\u8986\u5730\u7db2\u8def\u4e0a\u81ea\u539f\u59cb\u7db2\u8def\u50b3\u9001\u51fa\u4f86
2\u5177\u53ef\u64f4\u5145\u6027
3load balancing(\u8ca0\u8f09\u5747\u8861)
4\u6709\u6548\u7387\u7684\u5feb\u53d6\u5206\u4eab
5Network Congestion(\u7db2\u8def\u64c1\u64e0)\u4ee5\u53caBandwidth Consumption(\u7db2\u8def\u983b\u5bec\u4f7f\u7528)\u7684\u6539\u5584
6\u5206\u5c64\u7c21\u55ae\u7684\u8a2d\u5b9a\u7ba1\u7406\u3002
7\u63d0\u5347\u5feb\u53d6\u6548\u80fd\u914d\u5099:ex\u8a18\u61b6\u9ad4,\u7db2\u8def\u5361<\/p>\n\n\n\n
……………\u00a0<\/p>\n\n\n\n
\u73fe\u6709\u7684Web Caching Protocol(\u638c\u63a7\u5feb\u53d6\u4f3a\u670d\u5668\u7fa4\u4e4b\u9593\u5206\u4eab\u904b\u4f5c\u7684\u5354\u5b9a) <\/p>\n\n\n\n
HTCP(Hyper Text Caching Protocol)
\u3000\u76ee\u524d\u9084\u5c6c\u65bcInternet-Draft\u7684\u7814\u64ec\u968e\u6bb5\uff0c\u5305\u542b\u5982\u4f55\u767c\u73fe\u5feb\u53d6\u4f3a\u670d\u5668\u3001object\uff0c\u4ee5\u53ca\u5982\u4f55\u7ba1\u7406\u3001\u76e3\u770b\u5176\u904b\u4f5c
HTTP(HyperText Transfer Protocol)v1.1
\u3000\u63d0\u4f9b\u4e86\u4ee5\u4e0b\u76f8\u95dcHeader\u652f\u63f4Web Caching\u7684\u904b\u4f5c\uff1aCache-Control\u3001Age\u3001Pragma: no-cache\u3001Expires
\u3000\u652f\u63f4Persistent Connection(\u6301\u7e8c\u6027\u9023\u7dda)\uff1a\u5c0d\u540c\u4e00\u500b\u4f7f\u7528\u8005\u800c\u8a00\uff0c\u5728\u4e00\u77ed\u6642\u9593\u5167\u65bc\u7db2\u7ad9\u4e0a\u700f\u89bd\uff0c\u4e0d\u65b7\u5730\u81ea\u7db2\u7ad9\u4e0a\u63a5\u53d6\u8cc7\u6599\uff0cHTTP\u4e3b\u8981\u67b6\u69cb\u5728TCP (Transmission Control Protocol)\u7684\u57fa\u790e\u4e0a\uff0c\u4e0d\u65b7\u7684\u5efa\u7acb\u9023\u7dda\u3001\u63a5\u6536\u8cc7\u6599\u3001\u95dc\u9589\u9023\u7dda\uff0c\u5c0d\u65bc\u7db2\u8def\u7684\u4f7f\u7528\u8207\u7db2\u7ad9\u4f3a\u670d\u5668\u800c\u8a00\uff0c\u90fd\u6703\u5c0e\u81f4\u8f03\u5dee\u7684\u4f7f\u7528\u6548\u76ca\uff0c\u65bc\u662f\u63d0\u51fa\u6301\u7e8c\u6027\u9023\u7dda\u7684\u65b9\u6cd5\uff0c\u5728\u4e0d\u91cd\u65b0\u9023\u7dda\u7684\u60c5\u6cc1\u4e0b\uff0c\u53ef\u63a5\u53d6\u591a\u6b21\u8cc7\u6599\u63a5\u6536
ICP(Internet Caching Protocol,\u7db2\u8def\u5feb\u53d6\u50b3\u8f38\u5354\u5b9a)
Hierarchical(\u968e\u5c64\u5f0f) Caching 1995
\u7f3a\u9ede:\u592a\u591a\u7684ICP Query \/ Response\u8cc7\u6599\u5728\u5feb\u53d6\u4f3a\u670d\u5668\u7fa4\u4e4b\u9593\u50b3\u9001\uff0c\u660e\u986f\u5730\u589e\u52a0\u4e86\u4f7f\u7528\u8005\u7b49\u5f85\u6642\u9593\u3002\u800c\u4e14\u6703\u9020\u6210\u904e\u591a\u7684\u9023\u7dda\u8981\u6c42\u96c6\u4e2d\u5728\u55ae\u4e00\u7684\u5feb\u53d6\u4f3a\u670d\u5668\u4e0a\uff0c\u5728\u968e\u5c64\u5f0f\u5feb\u53d6\u67b6\u69cb\u4e0a\u5f80\u5f80\u6703\u7522\u751f\u904e\u5ea6\u96c6\u4e2d\u7684\u554f\u984c\uff0c\u4f7f\u5f97\u8a72\u5feb\u53d6\u4f3a\u670d\u5668\u6210\u70ba\u6574\u500b\u67b6\u69cb\u4e2d\u7684\u74f6\u9838\u3002\u4e26\u4e14\uff0c\u7576\u4e0a\u5c64\u7684\u67d0\u500b\u5feb\u53d6\u4f3a\u670d\u5668\u767c\u751f\u932f\u8aa4\uff0c\u7121\u6cd5\u63d0\u4f9b\u670d\u52d9\u6642\uff0c\u4e5f\u6703\u4f7f\u7684\u6574\u500b\u968e\u5c64\u5f0f\u67b6\u69cb\u7121\u6cd5\u7e7c\u7e8c\u904b\u4f5c
icpv2(Internet Cache Protocol v2,\u7db2\u969b\u7db2\u8def\u5feb\u53d6\u901a\u8a0a\u5354\u5b9a\u7b2c\u4e8c\u7248)
\u7531Squid\u4ee3\u7406\/\u5feb\u53d6\u4f3a\u670d\u5668\u6240\u4f7f\u7528,port:3130
CARP (Cache Array Routing Protocol)
Distributed (\u5206\u6563\u5f0f) Caching
Microsoft \u63d0\u51fa\uff0c\u5229\u7528URL-hashing\u7684\u65b9\u5f0f\u5c07WWW client\u7684\u9023\u7dda\u8981\u6c42\u5206\u6563\u5230\u6240\u6709\u53c3\u8207CARP\u904b\u4f5c\u7684\u5feb\u53d6\u4f3a\u670d\u5668\u7fa4\u4e2d\u3002\u7531\u65bcCARP\u4f7f\u7528URL-hashing\u7684\u65b9\u5f0f\uff0c\u4f86\u5206\u914d\u9023\u7dda\u8981\u6c42\uff0c\u7279\u5b9aURL\u7684object\u6703\u88ab\u6307\u5b9a\u5230\u7279\u5b9a\u4f3a\u670d\u5668\uff0c\u800c\u4e0d\u6703\u8003\u91cf\u5230WWW client characteristic\uff0c\u96d6\u7136\u53ef\u4ee5\u9020\u5c31\u5168\u57df\u6027\u7684\u5feb\u53d6\u67b6\u69cb\uff0c\u4f46\u6548\u7387\u4e0d\u4f73\uff0c\u4e14\u4e0d\u9069\u5408\u5728\u5340\u57df\u8f03\u5ee3\u7684Web Caching\u5206\u4eab\u74b0\u5883\u4e2d\u4f7f\u7528\u3002
CARP \u4f7f\u7528\u4ee5\u96dc\u8a0a\u70ba\u57fa\u790e\u7684\u8def\u7531\u65b9\u5f0f\u4f86\u5728\u9663\u5217\u4e2d\u63d0\u4f9b\u300c\u8981\u6c42\u89e3\u6790\u8def\u5f91 (request resolution path)\u300d\u3002\u8981\u6c42\u89e3\u6790\u8def\u5f91\u662f\u4ee5\u9663\u5217\u6210\u54e1\u8eab\u4efd\u53ca URL \u7684\u96dc\u8a0a\u70ba\u57fa\u790e\uff0c\u9019\u8868\u793a\u700f\u89bd\u5668\u6216\u4e0b\u6e38\u4ee3\u7406\u4f3a\u670d\u5668 (Proxy Server) \u53ef\u77ad\u89e3\u6240\u8981\u6c42\u7684\u8cc7\u8a0a\u662f\u5132\u5b58\u65bc\u9663\u5217\u7684\u4f55\u8655
WCCP(Web Cache Control Protocol)
HTTP packet routing
\u914d\u5408Cisco\u767c\u5c55\u7684Cache Engine\uff0c\u5c07Cache Engine\u4f9d\u9644\u5728\u8def\u7531\u5668\u4e0a\uff0c\u5177\u6709Transparent Web Caching\u7684\u7279\u6027\uff0cCache Engine\u513c\u7136\u5c31\u662f\u5feb\u53d6\u4f3a\u670d\u5668\uff0c\u7576cache hit\u767c\u751f\u6642\uff0c\u4fbf\u5c07object\u50b3\u56de\u7d66\u9023\u7dda\u8981\u6c42\u7aef\uff0c\u5426\u5247\u7576cache miss\u767c\u751f\u6642\uff0c\u4fbf\u5c07\u9023\u7dda\u8981\u6c42\u5f80\u4e0b\u500b\u8def\u7531\u5668\u8f49\u9001\uff0c\u76f4\u5230object\u6240\u5728\u7684\u539f\u59cb\u7db2\u7ad9\u70ba\u6b62\u3002user\u4e0d\u9700\u4efb\u4f55\u8a2d\u5b9a
\u7f3a\u9ede\u662f\uff0c\u6574\u500b\u7db2\u8def\u4e0a\u90fd\u5fc5\u9808\u5b89\u88ddCache Engine\uff0c\u56e0\u70ba\u5176\u5b83\u4e00\u822c\u7684\u8def\u7531\u5668\u63a5\u6536\u5230\u6b64\u9023\u7dda\u8981\u6c42\u4e4b\u5c01\u5305\uff0c\u4ecd\u820a\u6703\u7e7c\u7e8c\u5c07\u5c01\u5305\u50b3\u905e\u4e0b\u53bb\uff0c\u4f46\u6b64\u9023\u7dda\u8981\u6c42\u4e4b\u5c01\u5305\u76ee\u7684\u5730\u662fobject\u539f\u59cb\u7db2\u7ad9\uff0c\u800c\u4e0d\u662f\u67d0\u500b\u5feb\u53d6\u4f3a\u670d\u5668\uff0c\u5728\u9019\u7a2e\u60c5\u6cc1\u4e0b\uff0c\u96d6\u6709\u50b3\u7d71\u7684\u5feb\u53d6\u4f3a\u670d\u5668\u5b58\u5728\u7db2\u8def\u4e0a\uff0c\u4e5f\u662f\u5f92\u7136\u7121\u529f\uff0c\u7121\u6cd5\u4f7f\u7528\u3002
……………………….
\u76f8\u95dc\u8b70\u984c
Forced HTTP packet routing(\u5f37\u5236\u6027\u7684HTTP\u5c01\u5305routing)\uff1a
\u6703\u5f15\u81f4\u7db2\u8def\u6548\u7387\u4f4e\u843d\u3002HTTP\u5c01\u5305routing\u53c8\u7a31URL routing\uff0c\u985e\u4f3cIP-routing\u4f46\u537b\u662f\u4f7f\u7528URL\u4f86\u53d6\u4ee3IP\u4f4d\u5740\uff0c\u540c\u6a23\u5730\u52a0\u5165default routing\u3002 HTTP\u5c01\u5305routing\u7684\u7f3a\u9ede\u5728\u65bc\u9700\u8981\u66f4\u63db\u65b0\u7684\u8def\u7531\u5668\u8207routing\u6f14\u7b97\u6cd5\uff0c\u4e26\u4e14\u4e0d\u80fd\u8003\u91cf\u5230\u5feb\u53d6\u4f3a\u670d\u5668Application-Level\u8ca0\u8f09\u3002
Adaptive Cache\uff1a
\u8a2d\u8a08\u5efa\u69cb\u4e00\u500bGlobal(\u5168\u57df\u6027\u7684)\u7db2\u8def\u5feb\u53d6\u67b6\u69cb\u3002\u7531\u65bcHTTP\u5c01\u5305\u662f\u5728\u900f\u904erouting\u8def\u5f91\u9078\u64c7\uff0c\u7d93\u904e\u8def\u7531\u5668\u6216LAN\u4ea4\u63db\u5668\u5230\u9054\u7db2\u8def\u5feb\u53d6\u4f3a\u670d\u5668\u3002\u7576\u7db2\u8def\u5feb\u53d6\u4f3a\u670d\u5668\u767c\u751fcache miss\u6642\uff0c\u6700\u5f8c\u4e0d\u8ad6\u662f\u81ea\u5feb\u53d6\u4f3a\u670d\u5668\u6216\u539f\u59cb\u7db2\u7ad9\u6240\u53d6\u5f97\u7684object\u52e2\u5fc5\u90fd\u6703\u7d93\u904erouter\u5169\u6b21\uff0c\u6240\u4ee5\u91dd\u5c0d\u4ee5\u4e0a\u7684\u7f3a\u9ede\u52a0\u4ee5\u6539\u5584\u3002CGMP (Cache Group Management Protocol)\u4f7f\u7528multicast \u4f86\u81ea\u52d5\u767c\u73fe\u9130\u8fd1\u7684\u5feb\u53d6\u4f3a\u670d\u5668\uff0c\u4e26\u4e14\u80fd\u5920\u52d5\u614b\u8abf\u6574\u5f7c\u6b64\u4e4b\u9593\u7684\u95dc\u4fc2\u8207\u67b6\u69cb\u3002
Cache Digest\uff1a
\u5c07\u4f3a\u670d\u5668cache\u5167\u6240\u6709objects\u7684URL Table\u5229\u7528hash function\u7c21\u5316\u70badigest
\u7406\u5ff5:\u5feb\u53d6\u4f3a\u670d\u5668\u5f7c\u6b64\u9593\u4ea4\u63dbCache Digest\uff0c\u53ef\u4ee5\u5728\u6bcf\u9694\u4e00\u5b9a\u6642\u9593\u9032\u884c\u4ea4\u63db\uff0c\u6216\u662f\u8996\u60c5\u6cc1\u4f86\u9032\u884c\u4ea4\u63db
\u4f8b\u5982\uff1a\u7576False miss, False hit\u767c\u751f\u983b\u7387\u904e\u9ad8\u6642\u3002\u5176\u4e2dFalse miss\u6307\u7684\u662f\uff0c\u96d6\u7136Cache Digest\u5229\u7528Hashing Table\u7684\u6a5f\u5236\uff0c\u5c07URL\u5c0d\u6620\u5230\u67d0\u500b\u6578\u5b57\uff0c\u4f8b\u5982\uff1an\uff0c\u82e5\u67d0\u500bURL\u7684object\u6709\u5b58\u5728\u8a72\u5feb\u53d6\u4f3a\u670d\u5668\u4e2d\uff0c\u5c31\u6703\u8a18\u9304object\u76f8\u95dc\u8cc7\u8a0a\u5728Hashing Table\u7684\u7b2cn\u7b46\u6b04\u4f4d\u4e2d\u3002\u5176\u5b83\u5feb\u53d6\u4f3a\u670d\u5668\u53ea\u8981\u5c07\u6b64Hashing Table\u53d6\u56de\uff0c\u5373\u53ef\u4e0d\u9700\u8981\u9001\u51faICP Query\u4e5f\u4e0d\u9700\u8981\u7b49\u5f85ICP Response\u5c31\u53ef\u99ac\u4e0a\u77e5\u9053\u8a72\u5feb\u53d6\u4f3a\u670d\u5668\u4e2d\u662f\u5426\u64c1\u6709\u6b64URL\u7684object\uff0c\u5927\u5e45\u6e1b\u5c11ICP Query \/ Response
web\u9801\u9762\u4fdd\u7559\u65b9\u6cd5
\u555f\u767c\u5f0f\u6f14\u7b97\u6cd5heuristic
1\u731c\u6e2c\u4fdd\u5b58\u6bcf\u500b\u7db2\u9801\u6642\u9593\u9577\u5ea6,\u6839\u64dalast-modified\u8868\u982d\u63a8\u7b97\u4fdd\u5b58\u6642\u9593
2\u82e5\u7db2\u9801\u5728\u67d0\u6642\u524d\u88ab\u4fee\u6539,\u5247\u4fdd\u5b58\u5176\u5feb\u53d6\u7db2\u9801\u5230\u67d0\u6642
rfc2616\u8655\u7406
1\u4ee3\u7406\u7a0b\u5f0f\u9001\u7d66\u4f3a\u670d\u5668if-modified-since\u8981\u6c42\u8868\u982d,\u6307\u5b9a\u60f3\u8981\u7684\u7db2\u9801\u53ca\u88ab\u5feb\u53d6\u4e4b\u7db2\u9801last-modified(\u6700\u8fd1\u4fee\u6539\u6642\u9593)
2\u672a\u4fee\u6539\u5247\u56denot modified\u8a0a\u606f,\u4f7f\u7528\u5feb\u53d6\u5167\u7684\u7db2\u9801,\u82e5\u4fee\u6539\u5247\u50b3\u56de\u65b0\u7684\u5167\u5bb9
\u4e3b\u52d5\u5f0f\u5feb\u53d6
\u4ee3\u7406\u7a0b\u5f0f\u5f9e\u4f3a\u670d\u5668\u53d6\u5f97\u7db2\u9801\u5f8c,\u4fbf\u5c07\u6307\u5411\u8d85\u9023\u7d50\u7684\u7db2\u9801\u8f09\u5165\u5feb\u53d6
\u96d6\u53ef\u6e1b\u5c11\u5f8c\u7e8c\u8981\u6c42\u8655\u7406\u6642\u9593,\u4f46\u53ef\u80fd\u6709\u8655\u7406\u4e0d\u5b8c\u7684\u7db2\u9801
\u4f3a\u670d\u5668\u8907\u88fd
mirroring(\u93e1\u50cf\u8907\u88fd)\uff1a\u4f3a\u670d\u7aef\u5c07\u5167\u5bb9\u8907\u88fd\u5230\u591a\u500b\u4e14\u6563\u4f48\u5404\u8655\u7684\u4f4d\u7f6e
\u93e1\u50cf\u7db2\u7ad9\uff1a\u5b8c\u5168\u975c\u614b,\u53ef\u5c07\u5b8c\u6574\u6216\u90e8\u4efd\u5167\u5bb9\u653e\u5230\u6bcf\u500b\u5730\u9ede
\u6d41\u91cf\u7a81\u7136\u5927\u589e\u7684\u7db2\u7ad9\u6839\u64da\u9700\u8981\u628a\u81ea\u5df1\u8907\u88fd\u5230\u591a\u500b\u5730\u9ede,\u7b49\u5230\u7de9\u548c\u5f8c\u5728\u95dc\u9589\u7db2\u7ad9\uff1a\u9700\u65bc\u8a17\u7ba1\u7db2\u7ad9\u516c\u53f8\u5354\u8b70
CDN(content delivery networks,\u5167\u5bb9\u905e\u9001\u7db2\u8def)
\u5c07\u5167\u5bb9\u5f88\u6709\u6548\u7387\u5730\u63d0\u4f9b\u7d66\u7d42\u7aef\u4f7f\u7528\u8005,\u4e26\u6536\u53d6\u8cbb\u7528
1\u5167\u5bb9\u64c1\u6709\u8005\u5c07\u7db2\u7ad9\u5167\u5bb9\u4ea4\u7531CDN\u9032\u884c\u524d\u8655\u7406\u7a0b\u5f0f\u628aURL\u63db\u6389
2\u4fee\u6539\u904e\u7db2\u9801\u5b58\u5728\u5167\u5bb9\u64c1\u6709\u8005\u7db2\u7ad9,\u5f71\u50cf\u97f3\u8a0a\u7b49\u8cc7\u6599\u6539\u5728CDN\u4f3a\u670d\u5668\u4e0a\u6293\u53d6
3\u5c07CDN\u4f3a\u670d\u5668\u653e\u5165ISP\u7684LAN\u4e0a
CDN\u4f3a\u670d\u5668(CDN\u5047HTTP\u4f3a\u670d\u5668)
\u4e0d\u63d0\u4f9b\u4efb\u4f55\u5167\u5bb9
\u4e3b\u8981\u67e5\u51fa\u90a3\u500bCDN\u5167\u5bb9\u4f3a\u670d\u5668\u53ef\u63d0\u4f9b\u4f7f\u7528\u8005\u6700\u597d\u7684\u670d\u52d9
\u4e26\u5c07\u4f7f\u7528\u8005\u5c0e\u5f80CDN\u4f3a\u670d\u5668\uff08\u901a\u5e38\u662f\u4ee3\u7406\u7a0b\u5f0f\uff09
\u82e5\u4ee3\u7406\u7a0b\u5f0f\u7121\u6b64\u6a94\u5247\u5f9e\u771f\u5be6\u4f3a\u670d\u5668\u53d6\u51fa,\u4e26\u653e\u5165\u5feb\u53d6\u4ee5\u5099\u5f8c\u7e8c\u4f7f\u7528<\/p>\n","protected":false},"excerpt":{"rendered":"
Web Caching\u6548\u7387\u7684\u6539\u5584\u4e3b\u8981\u8457\u91cd\u5728\uff1a1\u63d0\u9ad8accum …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[29],"tags":[],"class_list":["post-861","post","type-post","status-publish","format-standard","hentry","category-osi-layer7"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/861","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/comments?post=861"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/861\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=861"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=861"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=861"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}