Windows上不同浏览器之间的保持活动和超时行为

简洁版本

为什么chrome发出保持活着的IE和FF不？

长版本

起初，我认为这是一个服务器端的问题。

我有一个Apache服务器，这是一个tomcat webapp的前端代理。这个应用程序的其中一个页面需要15-20分钟才能返回结果。我注意到，使用这个页面时，通过IE或FF访问时超时。如果您尝试访问networking时，您的networking电缆是否断开连接，则会转到标准的“无法访问”页面。在Chrome上，但是，它工作得很好。

这让我很好奇，所以我用服务器上的tcpdump窥探了stream量，这让我注意到了很大的差别。虽然IE和FF在它们超时之前一直保持沉默，但是chrome正在向服务器发送周期性的ACK数据包（并得到响应ACK）。另外值得注意的是，IE / FF似乎都发送了TCP断开连接，而不是从服务器收到任何超时。

所以是的，为什么IE浏览器/ FF断开时，Chrome不呢？为什么Chrome发送keep-alive和IE / FF不？

我试过在这个知识库文章中更改MS推荐的registry设置。它似乎没有改变任何行为。

来自IE的stream量示例（FF几乎相同）

23:25:56.814732 IP InternetExplorer.27378 > Server.https: . 83070:84430(1360) ack 154 win 65382 23:25:56.814976 IP InternetExplorer.27378 > Server.https: . 84430:85790(1360) ack 154 win 65382 23:25:56.814981 IP Server.https > InternetExplorer.27378: . ack 85790 win 63920 23:25:56.815201 IP InternetExplorer.27378 > Server.https: . 85790:87150(1360) ack 154 win 65382 23:25:56.815418 IP InternetExplorer.27378 > Server.https: . 87150:88510(1360) ack 154 win 65382 23:25:56.815422 IP Server.https > InternetExplorer.27378: . ack 88510 win 63920 23:25:56.815789 IP InternetExplorer.27378 > Server.https: . 88510:89870(1360) ack 154 win 65382 23:25:56.815916 IP InternetExplorer.27378 > Server.https: . 89870:91230(1360) ack 154 win 65382 23:25:56.815922 IP Server.https > InternetExplorer.27378: . ack 91230 win 63920 23:25:56.815929 IP InternetExplorer.27378 > Server.https: P 91230:91283(53) ack 154 win 65382 23:25:56.815940 IP Server.https > InternetExplorer.27378: . ack 91283 win 63920 23:25:56.858469 IP InternetExplorer.27378 > Server.https: . 91283:92643(1360) ack 154 win 65382 23:25:56.858773 IP InternetExplorer.27378 > Server.https: . 92643:94003(1360) ack 154 win 65382 23:25:56.858779 IP Server.https > InternetExplorer.27378: . ack 94003 win 63920 23:25:56.858992 IP InternetExplorer.27378 > Server.https: . 94003:95363(1360) ack 154 win 65382 23:25:56.859284 IP InternetExplorer.27378 > Server.https: . 95363:96723(1360) ack 154 win 65382 23:25:56.859288 IP Server.https > InternetExplorer.27378: . ack 96723 win 63920 23:25:56.859483 IP InternetExplorer.27378 > Server.https: . 96723:98083(1360) ack 154 win 65382 23:25:56.859731 IP InternetExplorer.27378 > Server.https: . 98083:99443(1360) ack 154 win 65382 23:25:56.859734 IP Server.https > InternetExplorer.27378: . ack 99443 win 63920 23:25:56.859737 IP InternetExplorer.27378 > Server.https: P 99443:99496(53) ack 154 win 65382 23:25:56.859743 IP Server.https > InternetExplorer.27378: . ack 99496 win 63920 23:25:56.902029 IP InternetExplorer.27378 > Server.https: . 99496:100856(1360) ack 154 win 65382 23:25:56.902484 IP InternetExplorer.27378 > Server.https: . 100856:102216(1360) ack 154 win 65382 23:25:56.902489 IP Server.https > InternetExplorer.27378: . ack 102216 win 63920 23:25:56.902585 IP InternetExplorer.27378 > Server.https: . 102216:103576(1360) ack 154 win 65382 23:25:56.902932 IP InternetExplorer.27378 > Server.https: . 103576:104936(1360) ack 154 win 65382 23:25:56.902935 IP Server.https > InternetExplorer.27378: . ack 104936 win 63920 23:25:56.903045 IP InternetExplorer.27378 > Server.https: P 104936:105622(686) ack 154 win 65382 23:25:56.903052 IP Server.https > InternetExplorer.27378: . ack 105622 win 63920 23:30:42.621188 IP InternetExplorer.27378 > Server.https: R 105622:105622(0) ack 154 win 9300

来自Chrome的stream量示例：

 21:58:54.534554 IP chrome.20353 > server.https: P 10125:11337(1212) ack 146 win 65303 21:58:54.534566 IP server.https > chrome.20353: . ack 11337 win 29088 21:58:54.534621 IP chrome.20353 > server.https: P 11337:12549(1212) ack 146 win 65303 21:58:54.534625 IP server.https > chrome.20353: . ack 12549 win 31512 21:58:54.534961 IP chrome.20353 > server.https: . 12549:13761(1212) ack 146 win 65303 21:58:54.534966 IP server.https > chrome.20353: . ack 13761 win 33936 21:58:54.535082 IP chrome.20353 > server.https: P 13761:14392(631) ack 146 win 65303 21:58:54.535086 IP server.https > chrome.20353: . ack 14392 win 36360 21:59:40.021420 IP chrome.20353 > server.https: . ack 146 win 65303 21:59:40.021437 IP server.https > chrome.20353: . ack 14392 win 36360 22:00:25.147256 IP chrome.20353 > server.https: . ack 146 win 65303 22:00:25.147307 IP server.https > chrome.20353: . ack 14392 win 36360 22:01:10.244639 IP chrome.20353 > server.https: . ack 146 win 65303 22:01:10.244669 IP server.https > chrome.20353: . ack 14392 win 36360 22:01:55.410540 IP chrome.20353 > server.https: . ack 146 win 65303 22:01:55.410560 IP server.https > chrome.20353: . ack 14392 win 36360 22:02:40.568607 IP chrome.20353 > server.https: . ack 146 win 65303 22:02:40.568642 IP server.https > chrome.20353: . ack 14392 win 36360 22:03:25.720408 IP chrome.20353 > server.https: . ack 146 win 65303 22:03:25.720438 IP server.https > chrome.20353: . ack 14392 win 36360 22:04:10.861881 IP chrome.20353 > server.https: . ack 146 win 65303 22:04:10.861914 IP server.https > chrome.20353: . ack 14392 win 36360 22:04:55.977031 IP chrome.20353 > server.https: . ack 146 win 65303 22:04:55.977063 IP server.https > chrome.20353: . ack 14392 win 36360 22:05:41.085828 IP chrome.20353 > server.https: . ack 146 win 65303 22:05:41.085848 IP server.https > chrome.20353: . ack 14392 win 36360 22:06:26.251530 IP chrome.20353 > server.https: . ack 146 win 65303 22:06:26.251550 IP server.https > chrome.20353: . ack 14392 win 36360 22:07:11.416086 IP chrome.20353 > server.https: . ack 146 win 65303 22:07:11.416154 IP server.https > chrome.20353: . ack 14392 win 36360 22:07:56.554244 IP chrome.20353 > server.https: . ack 146 win 65303 22:07:56.554275 IP server.https > chrome.20353: . ack 14392 win 36360 22:08:41.713610 IP chrome.20353 > server.https: . ack 146 win 65303 22:08:41.713628 IP server.https > chrome.20353: . ack 14392 win 36360 22:09:26.874657 IP chrome.20353 > server.https: . ack 146 win 65303 22:09:26.874684 IP server.https > chrome.20353: . ack 14392 win 36360 22:10:12.033494 IP chrome.20353 > server.https: . ack 146 win 65303 22:10:12.033512 IP server.https > chrome.20353: . ack 14392 win 36360 22:10:57.266808 IP chrome.20353 > server.https: . ack 146 win 65303 22:10:57.266846 IP server.https > chrome.20353: . ack 14392 win 36360 22:11:42.453183 IP chrome.20353 > server.https: . ack 146 win 65303 22:11:42.453204 IP server.https > chrome.20353: . ack 14392 win 36360 22:12:27.599746 IP chrome.20353 > server.https: . ack 146 win 65303 22:12:27.599787 IP server.https > chrome.20353: . ack 14392 win 36360 22:13:12.762650 IP chrome.20353 > server.https: . ack 146 win 65303 22:13:12.762682 IP server.https > chrome.20353: . ack 14392 win 36360 22:13:57.923229 IP chrome.20353 > server.https: . ack 146 win 65303 22:13:57.923248 IP server.https > chrome.20353: . ack 14392 win 36360 22:14:43.077688 IP chrome.20353 > server.https: . ack 146 win 65303 22:14:43.077716 IP server.https > chrome.20353: . ack 14392 win 36360 22:15:28.252353 IP chrome.20353 > server.https: . ack 146 win 65303 22:15:28.252372 IP server.https > chrome.20353: . ack 14392 win 36360 22:16:13.424019 IP chrome.20353 > server.https: . ack 146 win 65303 22:16:13.424050 IP server.https > chrome.20353: . ack 14392 win 36360 22:16:58.564352 IP chrome.20353 > server.https: . ack 146 win 65303 22:16:58.564368 IP server.https > chrome.20353: . ack 14392 win 36360 22:17:43.725261 IP chrome.20353 > server.https: . ack 146 win 65303 22:17:43.725291 IP server.https > chrome.20353: . ack 14392 win 36360 22:17:48.597411 IP server.https > chrome.20353: . 146:2570(2424) ack 14392 win 36360 22:17:48.682782 IP chrome.20353 > server.https: . ack 2570 win 65448 22:17:48.682804 IP server.https > chrome.20353: . 2570:6206(3636) ack 14392 win 36360 22:17:48.785650 IP chrome.20353 > server.https: . ack 6206 win 65448 22:17:48.785666 IP server.https > chrome.20353: . 6206:11054(4848) ack 14392 win 36360 22:17:48.894777 IP chrome.20353 > server.https: . ack 8630 win 65448 22:17:48.894792 IP server.https > chrome.20353: . 11054:14690(3636) ack 14392 win 36360 22:17:48.905976 IP chrome.20353 > server.https: . ack 11054 win 65448 22:17:48.905990 IP server.https > chrome.20353: . 14690:17114(2424) ack 14392 win 36360 22:17:48.905996 IP server.https > chrome.20353: P 17114:17420(306) ack 14392 win 36360 22:17:48.998232 IP chrome.20353 > server.https: . ack 15902 win 65448 22:17:49.293519 IP server.https > chrome.20353: . 15902:17114(1212) ack 14392 win 36360 22:17:49.412748 IP chrome.20353 > server.https: . ack 17420 win 65448 22:17:49.921452 IP chrome.20353 > server.https: P 14392:14685(293) ack 17420 win 65448 22:17:49.921493 IP server.https > chrome.20353: . ack 14685 win 38784 22:17:49.922027 IP server.https > chrome.20353: P 17420:17862(442) ack 14685 win 38784 22:17:50.323363 IP chrome.20353 > server.https: . ack 17862 win 65006 22:18:04.921966 IP server.https > chrome.20353: P 17862:17899(37) ack 14685 win 38784 22:18:04.922078 IP server.https > chrome.20353: F 17899:17899(0) ack 14685 win 38784 22:18:05.080745 IP chrome.20353 > server.https: . ack 17900 win 64969 22:18:10.030035 IP chrome.20353 > server.https: F 14685:14685(0) ack 17900 win 64969 22:18:10.030079 IP server.https > chrome.20353: . ack 14686 win 38784

我没有答案为什么，但我也观察到了同样的行为。我在这里logging了我的发现。

http://app-inf.blogspot.com/2012/09/browser-load-balancer-web-server-mod-jk.html

可能没有办法改变IE发送Keep-alive信号，但是我们改变了负载均衡器“Keep Alive Interval”的设置来保持连接。希望这有助于。