\u9019\u662f\u6839\u64da\u81ea\u5df1\u7684\u7b46\u8a18\u6574\u7406\u7684,\u5982\u6709\u932f\u8aa4,\u6b61\u8fce\u6307\u51fa\u4f86. \u3000\u3000tcp\u5354\u8b70\u672c\u8eab\u662f\u53ef\u9760\u7684,\u4e26\u4e0d\u7b49\u65bc\u61c9\u7528\u7a0b\u5e8f\u7528tcp\u767c\u9001\u6578\u64da\u5c31\u58f9\u5b9a\u662f\u53ef\u9760\u7684.\u4e0d\u7ba1\u662f\u5426\u963b\u585e,send\u767c\u9001\u7684\u5927\u5c0f,\u4e26\u4e0d\u4ee3\u8868\u5c0d\u7aefrecv\u5230\u591a\u5c11\u7684\u6578\u64da. \u3000\u3000\u5728\u963b\u585e\u6a21\u5f0f\u4e0b,send\u51fd\u6578\u7684\u904e\u7a0b\u662f\u5c07\u61c9\u7528\u7a0b\u5e8f\u8acb\u6c42\u767c\u9001\u7684\u6578\u64da\u62f7\u8c9d\u5230\u767c\u9001\u7de9\u5b58\u4e2d\u767c\u9001\u4e26\u5f97\u5230\u78ba\u8a8d\u5f8c\u518d\u8fd4\u56de.\u4f46\u7531\u65bc\u767c\u9001\u7de9\u5b58\u7684\u5b58\u5728,\u8868\u73fe\u70ba:\u5982\u679c\u767c\u9001\u7de9\u5b58\u5927\u5c0f\u6bd4\u8acb\u6c42\u767c\u9001\u7684\u5927\u5c0f\u8981\u5927,\u90a3\u9ebdsend\u51fd\u6578\u7acb\u5373\u8fd4\u56de,\u540c\u6642\u5411\u7db2\u7d61\u4e2d\u767c\u9001\u6578\u64da;\u5426\u5247,send\u5411\u7db2\u7d61\u767c\u9001\u7de9\u5b58\u4e2d\u4e0d\u80fd\u5bb9\u7d0d\u7684\u90a3\u90e8\u5206\u6578\u64da,\u4e26\u7b49\u5f85\u5c0d\u7aef\u78ba\u8a8d\u5f8c\u518d\u8fd4\u56de(\u63a5\u6536\u7aef\u53ea\u8981\u5c07\u6578\u64da\u6536\u5230\u63a5\u6536\u7de9\u5b58\u4e2d,\u5c31\u6703\u78ba\u8a8d,\u4e26\u4e0d\u58f9\u5b9a\u8981\u7b49\u5f85\u61c9\u7528\u7a0b\u5e8f\u8abf\u7528recv); \u3000\u3000\u5728\u975e\u963b\u585e\u6a21\u5f0f\u4e0b,send\u51fd\u6578\u7684\u904e\u7a0b\u50c5\u50c5\u662f\u5c07\u6578\u64da\u62f7\u8c9d\u5230\u5354\u8b70\u68e7\u7684\u7de9\u5b58\u5340\u800c\u5df2,\u5982\u679c\u7de9\u5b58\u5340\u53ef\u7528\u7a7a\u9593\u4e0d\u5920,\u5247\u76e1\u80fd\u529b\u7684\u62f7\u8c9d,\u8fd4\u56de\u6210\u529f\u62f7\u8c9d\u7684\u5927\u5c0f;\u5982\u7de9\u5b58\u5340\u53ef\u7528\u7a7a\u9593\u70ba0,\u5247\u8fd4\u56de-1,\u540c\u6642\u8a2d\u7f6eerrno\u70baEAGAIN. \u3000\u3000linux\u4e0b\u53ef\u7528sysctl -a | grep net.ipv4.tcp_wmem\u67e5\u770b\u7cfb\u7d71\u9ed8\u8a8d\u7684\u767c\u9001\u7de9\u5b58\u5927\u5c0f: \u3000\u3000net.ipv4.tcp_wmem = 4096 16384 81920 \u3000\u3000\u9019\u6709\u4e09\u500b\u503c,\u7b2c\u58f9\u500b\u503c\u662fsocket\u7684\u767c\u9001\u7de9\u5b58\u5340\u5206\u914d\u7684\u6700\u5c11\u5b57\u7bc0\u6578,\u7b2c\u4e8c\u500b\u503c\u662f\u9ed8\u8a8d\u503c(\u8a72\u503c\u6703\u88abnet.core.wmem_default\u8986\u84cb),\u7de9\u5b58\u5340\u5728\u7cfb\u7d71\u8ca0\u8f09\u4e0d\u91cd\u7684\u60c5\u6cc1\u4e0b\u53ef\u4ee5\u589e\u9577\u5230\u9019\u500b\u503c,\u7b2c\u4e09\u500b\u503c\u662f\u767c\u9001\u7de9\u5b58\u5340\u7a7a\u9593\u7684\u6700\u5927\u5b57\u7bc0\u6578(\u8a72\u503c\u6703\u88abnet.core.wmem_max\u8986\u84cb). \u3000\u3000\u6839\u64da\u5be6\u969b\u6e2c\u8a66,\u5982\u679c\u624b\u5de5\u66f4\u6539\u4e86net.ipv4.tcp_wmem\u7684\u503c,\u5247\u6703\u6309\u66f4\u6539\u7684\u503c\u4f86\u904b\u884c,\u5426\u5247\u5728\u9ed8\u8a8d\u60c5\u6cc1\u4e0b,\u5354\u8b70\u68e7\u901a\u5e38\u662f\u6309net.core.wmem_default\u548cnet.core.wmem_max\u7684\u503c\u4f86\u5206\u914d\u5167\u5b58\u7684. \u3000\u3000\u61c9\u7528\u7a0b\u5e8f\u61c9\u8a72\u6839\u64da\u61c9\u7528\u7684\u7279\u6027\u5728\u7a0b\u5e8f\u4e2d\u66f4\u6539\u767c\u9001\u7de9\u5b58\u5927\u5c0f: \u3000\u3000socklen_t sendbuflen = 0; \u3000\u3000socklen_t len = sizeof(sendbuflen); \u3000\u3000getsockopt(clientSocket, SOL_SOCKET, SO_SNDBUF, (void*)&sendbuflen, &len); \u3000\u3000printf(“default,sendbuf:%d\\n”, sendbuflen); \u3000\u3000sendbuflen = 10240; \u3000\u3000setsockopt(clientSocket, SOL_SOCKET, SO_SNDBUF, (void*)&sendbuflen, len); \u3000\u3000getsockopt(clientSocket, SOL_SOCKET, SO_SNDBUF, (void*)&sendbuflen, &len); \u3000\u3000printf(“now,sendbuf:%d\\n”, sendbuflen); \u3000\u3000\u9700\u8981\u8a3b\u610f\u7684\u662f,\u96d6\u7136\u5c07\u767c\u9001\u7de9\u5b58\u8a2d\u7f6e\u6210\u4e8610k,\u4f46\u5be6\u969b\u4e0a,\u5354\u8b70\u68e7\u6703\u5c07\u5176\u64f4\u59271\u500d,\u8a2d\u70ba20k. \u3000\u3000——————-\u5be6\u4f8b\u5206\u6790———————- \u3000\u3000\u5728\u5be6\u969b\u61c9\u7528\u4e2d,\u5982\u679c\u767c\u9001\u7aef\u662f\u975e\u963b\u585e\u767c\u9001,\u7531\u65bc\u7db2\u7d61\u7684\u963b\u585e\u6216\u8005\u63a5\u6536\u7aef\u8655\u7406\u904e\u6162,\u901a\u5e38\u51fa\u73fe\u7684\u60c5\u6cc1\u662f,\u767c\u9001\u61c9\u7528\u7a0b\u5e8f\u770b\u8d77\u4f86\u767c\u9001\u4e8610k\u7684\u6578\u64da,\u4f46\u662f\u53ea\u767c\u9001\u4e862k\u5230\u5c0d\u7aef\u7de9\u5b58\u4e2d,\u9084\u67098k\u5728\u672c\u6a5f\u7de9\u5b58\u4e2d(\u672a\u767c\u9001\u6216\u8005\u672a\u5f97\u5230\u63a5\u6536\u7aef\u7684\u78ba\u8a8d).\u90a3\u9ebd\u6b64\u6642,\u63a5\u6536\u61c9\u7528\u7a0b\u5e8f\u80fd\u5920\u6536\u5230\u7684\u6578\u64da\u70ba2k.\u5047\u5982\u63a5\u6536\u61c9\u7528\u7a0b\u5e8f\u8abf\u7528recv\u51fd\u6578\u7372\u53d6\u4e861k\u7684\u6578\u64da\u5728\u8655\u7406,\u5728\u9019\u500b\u77ac\u9593,\u767c\u751f\u4e86\u4ee5\u4e0b\u60c5\u6cc1\u4e4b\u58f9: \u3000\u3000A. \u767c\u9001\u61c9\u7528\u7a0b\u5e8f\u8a8d\u70basend\u5b8c\u4e8610k\u6578\u64da,\u95dc\u9589\u4e86socket: \u3000\u3000\u767c\u9001\u4e3b\u6a5f\u4f5c\u70batcp\u7684\u4e3b\u52d5\u95dc\u9589\u8005,\u9023\u63a5\u5c07\u8655\u65bcFIN_WAIT1\u7684\u534a\u95dc\u9589\u72c0\u614b(\u7b49\u5f85\u5c0d\u65b9\u7684ack),\u4e26\u4e14,\u767c\u9001\u7de9\u5b58\u4e2d\u76848k\u6578\u64da\u4e26\u4e0d\u6e05\u9664,\u4f9d\u7136\u6703\u767c\u9001\u7d66\u5c0d\u7aef.\u5982\u679c\u63a5\u6536\u61c9\u7528\u7a0b\u5e8f\u4f9d\u7136\u5728recv,\u90a3\u9ebd\u5b83\u6703\u6536\u5230\u4f59\u4e0b\u76848k\u6578\u64da(\u9019\u500b\u524d\u984c\u662f,\u63a5\u6536\u7aef\u6703\u5728\u767c\u9001\u7aefFIN_WAIT1\u72c0\u614b\u8d85\u6642\u524d\u6536\u5230\u4f59\u4e0b\u76848k\u6578\u64da.),\u7136\u5f8c\u5f97\u5230\u58f9\u500b\u5c0d\u7aefsocket\u88ab\u95dc\u9589\u7684\u6d88\u606f(recv\u8fd4\u56de0).\u9019\u6642,\u61c9\u8a72\u9032\u884c\u95dc\u9589. \u3000\u3000B. \u767c\u9001\u61c9\u7528\u7a0b\u5e8f\u518d\u6b21\u8abf\u7528send\u767c\u90018k\u7684\u6578\u64da: \u3000\u3000\u5047\u5982\u767c\u9001\u7de9\u5b58\u7684\u7a7a\u9593\u70ba20k,\u90a3\u9ebd\u767c\u9001\u7de9\u5b58\u53ef\u7528\u7a7a\u9593\u70ba20-8=12k,\u5927\u65bc\u8acb\u6c42\u767c\u9001\u76848k,\u6240\u4ee5send\u51fd\u6578\u5c07\u6578\u64da\u505a\u62f7\u8c9d\u5f8c,\u4e26\u7acb\u5373\u8fd4\u56de8192; \u3000\u3000\u5047\u5982\u767c\u9001\u7de9\u5b58\u7684\u7a7a\u9593\u70ba12k,\u90a3\u9ebd\u6b64\u6642\u767c\u9001\u7de9\u5b58\u53ef\u7528\u7a7a\u9593\u9084\u670912-8=4k,send()\u6703\u8fd4\u56de4096,\u61c9\u7528\u7a0b\u5e8f\u767c\u73fe\u8fd4\u56de\u7684\u503c\u5c0f\u65bc\u8acb\u6c42\u767c\u9001\u7684\u5927\u5c0f\u503c\u5f8c,\u53ef\u4ee5\u8a8d\u70ba\u7de9\u5b58\u5340\u5df2\u6eff,\u9019\u6642\u5fc5\u9808\u963b\u585e(\u6216\u901a\u904eselect\u7b49\u5f85\u4e0b\u58f9\u6b21socket\u53ef\u5beb\u7684\u4fe1\u865f),\u5982\u679c\u61c9\u7528\u7a0b\u5e8f\u4e0d\u7406\u6703,\u7acb\u5373\u518d\u6b21\u8abf\u7528send,\u90a3\u9ebd\u6703\u5f97\u5230-1\u7684\u503c,\u5728linux\u4e0b\u8868\u73fe\u70baerrno=EAGAIN. \u3000\u3000C. \u63a5\u6536\u61c9\u7528\u7a0b\u5e8f\u5728\u8655\u7406\u5b8c1k\u6578\u64da\u5f8c,\u95dc\u9589\u4e86socket: \u3000\u3000\u63a5\u6536\u4e3b\u6a5f\u4f5c\u70ba\u4e3b\u52d5\u95dc\u9589\u8005,\u9023\u63a5\u5c07\u8655\u65bcFIN_WAIT1\u7684\u534a\u95dc\u9589\u72c0\u614b(\u7b49\u5f85\u5c0d\u65b9\u7684ack).\u7136\u5f8c,\u767c\u9001\u61c9\u7528\u7a0b\u5e8f\u6703\u6536\u5230socket\u53ef\u8b80\u7684\u4fe1\u865f(\u901a\u5e38\u662fselect\u8abf\u7528\u8fd4\u56desocket\u53ef\u8b80),\u4f46\u5728\u8b80\u53d6\u6642\u6703\u767c\u73ferecv\u51fd\u6578\u8fd4\u56de0,\u9019\u6642\u61c9\u8a72\u8abf\u7528close\u51fd\u6578\u4f86\u95dc\u9589socket(\u767c\u9001\u7d66\u5c0d\u65b9ack); \u3000\u3000\u5982\u679c\u767c\u9001\u61c9\u7528\u7a0b\u5e8f\u6c92\u6709\u8655\u7406\u9019\u500b\u53ef\u8b80\u7684\u4fe1\u865f,\u800c\u662f\u7e7c\u7e8c\u8abf\u7528send,\u90a3\u9ebd\u7b2c\u58f9\u6b21\u6703\u50cf\u5f80\u5e38\u58f9\u6a23\u7e7c\u7e8c\u586b\u5145\u7de9\u5b58\u5340,\u7136\u5f8c\u8fd4\u56de,\u4f46\u5982\u679c\u518d\u6b21\u8abf\u7528send,\u9032\u7a0b\u6703\u6536\u5230SIGPIPE\u4fe1\u865f,\u8a72\u4fe1\u865f\u7684\u9ed8\u8a8d\u97ff\u61c9\u52d5\u4f5c\u662f\u9000\u51fa\u9032\u7a0b. \u3000\u3000D. \u4ea4\u63db\u6a5f\u6216\u8def\u7531\u5668\u7684\u7db2\u7d61\u65b7\u958b: \u3000\u3000\u63a5\u6536\u61c9\u7528\u7a0b\u5e8f\u5728\u8655\u7406\u5b8c\u5df2\u6536\u5230\u76841k\u6578\u64da\u5f8c,\u6703\u7e7c\u7e8c\u5f9e\u7de9\u5b58\u5340\u8b80\u53d6\u4f59\u4e0b\u76841k\u6578\u64da,\u7136\u5f8c\u5c31\u8868\u73fe\u70ba\u7121\u6578\u64da\u53ef\u8b80\u7684\u73fe\u8c61,\u9019\u7a2e\u60c5\u6cc1\u9700\u8981\u61c9\u7528\u7a0b\u5e8f\u4f86\u8655\u7406\u8d85\u6642.\u58f9\u822c\u505a\u6cd5\u662f\u8a2d\u5b9a\u58f9\u500bselect\u7b49\u5f85\u7684\u6700\u5927\u6642\u9593,\u5982\u679c\u8d85\u51fa\u9019\u500b\u6642\u9593\u4f9d\u7136\u6c92\u6709\u6578\u64da\u53ef\u8b80,\u5247\u8a8d\u70basocket\u5df2\u4e0d\u53ef\u7528. \u3000\u3000\u767c\u9001\u61c9\u7528\u7a0b\u5e8f\u6703\u4e0d\u65b7\u7684\u5c07\u4f59\u4e0b\u7684\u6578\u64da\u767c\u9001\u5230\u7db2\u7d61\u4e0a,\u4f46\u59cb\u7d42\u5f97\u4e0d\u5230\u78ba\u8a8d,\u6240\u4ee5\u7de9\u5b58\u5340\u7684\u53ef\u7528\u7a7a\u9593\u6301\u7e8c\u70ba0,\u9019\u7a2e\u60c5\u6cc1\u4e5f\u9700\u8981\u61c9\u7528\u7a0b\u5e8f\u4f86\u8655\u7406. \u3000\u3000\u5982\u679c\u4e0d\u7531\u61c9\u7528\u7a0b\u5e8f\u4f86\u8655\u7406\u9019\u7a2e\u60c5\u6cc1\u8d85\u6642\u7684\u60c5\u6cc1,\u4e5f\u53ef\u4ee5\u901a\u904etcp\u5354\u8b70\u672c\u8eab\u4f86\u8655\u7406,\u5177\u9ad4\u53ef\u4ee5\u67e5\u770bsysctl\u9805\u4e2d\u7684: \u3000\u3000net.ipv4.tcp_keepalive_intvl \u3000\u3000net.ipv4.tcp_keepalive_probes \u3000\u3000net.ipv4.tcp_keepalive_time \u3000\u3000\u6240\u4ee5,\u8981\u60f3\u7de8\u5beb\u512a\u79c0\u7684socket\u7a0b\u5e8f\u4e5f\u662f\u5f88\u4e0d\u5bb9\u6613\u7684.\u7279\u5225\u662f\u5728\u70ba\u61c9\u7528\u505a\u512a\u5316\u6642,\u5f88\u591a\u5de5\u4f5c\u90fd\u975e\u5e38\u7684\u7169\u7463.<\/p>\n","protected":false},"excerpt":{"rendered":"
\u9019\u662f\u6839\u64da\u81ea\u5df1\u7684\u7b46\u8a18\u6574\u7406\u7684,\u5982\u6709\u932f\u8aa4,\u6b61\u8fce\u6307\u51fa\u4f86. \u3000\u3000tcp\u5354\u8b70\u672c\u8eab\u662f\u53ef\u9760\u7684,\u4e26\u4e0d\u7b49\u65bc\u61c9\u7528\u7a0b\u5e8f\u7528tcp\u767c\u9001\u6578\u64da […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[531],"tags":[295,628],"class_list":["post-1572","post","type-post","status-publish","format-standard","hentry","category-unix","tag-linux","tag-tcp"],"_links":{"self":[{"href":"https:\/\/www.killtest.hk\/index.php\/wp-json\/wp\/v2\/posts\/1572","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.killtest.hk\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.killtest.hk\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.killtest.hk\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.killtest.hk\/index.php\/wp-json\/wp\/v2\/comments?post=1572"}],"version-history":[{"count":0,"href":"https:\/\/www.killtest.hk\/index.php\/wp-json\/wp\/v2\/posts\/1572\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.killtest.hk\/index.php\/wp-json\/wp\/v2\/media?parent=1572"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.killtest.hk\/index.php\/wp-json\/wp\/v2\/categories?post=1572"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.killtest.hk\/index.php\/wp-json\/wp\/v2\/tags?post=1572"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}