Hey I have a LVS loadbalancer (keepalived) that causes some problems...
First, the network - same physical network: firewall bond0 10.0.101.1 (forwards port 80 to 10.0.101.100) loadbalancer bond0 10.0.101.100 (corosync/pacemaker cluster real IPs are 10.0.101.101 and 10.0.101.102) loadbalancer bond0 10.0.102.1 (webserver network) webservers bond0 10.0.102.121-128 (only 121 is active during the following tests). To avoid redirects, the loadbalancer has send_redirects and accept_redirects disabled. Connections through the loadbalancer to a webserver are connected fine, but as soon as the http request is sent it causes problem when the response is large (in this case 10K is enough to make it fail). Examples with 1K and 10K files through loadbalancer: $ ab -c 10 -n 100 http://10.0.101.100/1K Document Path: /1K Document Length: 1024 bytes Time taken for tests: 0.069 seconds Requests per second: 1456.39 [#/sec] (mean) Time per request: 6.866 [ms] (mean) Time per request: 0.687 [ms] (mean, across all concurrent requests) Transfer rate: 1825.56 [Kbytes/sec] received $ ab -c 10 -n 100 http://10.0.101.100/10K Document Path: /10K Document Length: 10240 bytes Time taken for tests: 2.373 seconds Requests per second: 42.14 [#/sec] (mean) Time per request: 237.317 [ms] (mean) Time per request: 23.732 [ms] (mean, across all concurrent requests) Transfer rate: 432.03 [Kbytes/sec] received Examples with 1K and 10K files directly to webserver: $ ab -c 10 -n 100 http://10.0.102.121/1K Document Path: /1K Document Length: 1024 bytes Time taken for tests: 0.069 seconds Requests per second: 1459.04 [#/sec] (mean) Time per request: 6.854 [ms] (mean) Time per request: 0.685 [ms] (mean, across all concurrent requests) Transfer rate: 1825.23 [Kbytes/sec] received $ ab -c 10 -n 100 http://10.0.102.121/10K Document Path: /10K Document Length: 10240 bytes Time taken for tests: 0.101 seconds Requests per second: 988.28 [#/sec] (mean) Time per request: 10.119 [ms] (mean) Time per request: 1.012 [ms] (mean, across all concurrent requests) Transfer rate: 10200.69 [Kbytes/sec] received This shows that if the filesize is small enough it works fine, but when the size grows, something goes wrong... I have been looking at tcpdumps, but haven't figured out what excatly happens - but it looks like a ACK from the client doesn't get through to the webserver and it therefore waits and retransmits. /Anders _______________________________________________ Please read the documentation before posting - it's available at: http://www.linuxvirtualserver.org/ LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org Send requests to lvs-users-requ...@linuxvirtualserver.org or go to http://lists.graemef.net/mailman/listinfo/lvs-users
