Hi, I'm trying to understand how to load balancing works and testing it's benefits, and I'm in a trouble: in my tests (using ab command) I got better performance without the load balancer.
I try to describe my environment... I created three VM on Virtualbox with the same hardware and software configuration and redirected ports using NAT: CPU: 1 RAM: 1024MB Network: NAT Apache version: 2.4.41 Kernel: Linux node1 5.4.0-73-generic #82-Ubuntu SMP Wed Apr 14 17:39:42 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux OS: Ubuntu server 20.04.2 The machines: central: only acts as a load balancer (not a balancer member), otherwise used as 'normal' apache server for results comparison. NAT from 8010 to 80 node1: when load balancer is configured in the central machine, acts as balancer member. NAT from 8011 to 80 node2: when load balancer is configured in the central machine, acts as balancer member. NAT from 8012 to 80 Here a list of apache loaded module. spoiler!!! node1 and node2 have the same modules. central have the same modules as nod1 and node2 plus lbmethod_byrequests_module (shared)... Apache loaded modules in central: Loaded Modules: core_module (static) so_module (static) watchdog_module (static) http_module (static) log_config_module (static) logio_module (static) version_module (static) unixd_module (static) access_compat_module (shared) alias_module (shared) auth_basic_module (shared) authn_core_module (shared) authn_file_module (shared) authz_core_module (shared) authz_host_module (shared) authz_user_module (shared) autoindex_module (shared) deflate_module (shared) dir_module (shared) env_module (shared) filter_module (shared) lbmethod_byrequests_module (shared) mime_module (shared) mpm_event_module (shared) negotiation_module (shared) proxy_module (shared) proxy_balancer_module (shared) proxy_http_module (shared) reqtimeout_module (shared) setenvif_module (shared) slotmem_shm_module (shared) status_module (shared) Apache loaded modules in node1: core_module (static) so_module (static) watchdog_module (static) http_module (static) log_config_module (static) logio_module (static) version_module (static) unixd_module (static) access_compat_module (shared) alias_module (shared) auth_basic_module (shared) authn_core_module (shared) authn_file_module (shared) authz_core_module (shared) authz_host_module (shared) authz_user_module (shared) autoindex_module (shared) deflate_module (shared) dir_module (shared) env_module (shared) filter_module (shared) mime_module (shared) mpm_event_module (shared) negotiation_module (shared) proxy_module (shared) proxy_balancer_module (shared) proxy_http_module (shared) reqtimeout_module (shared) setenvif_module (shared) slotmem_shm_module (shared) status_module (shared) Apache loaded modules in node2: core_module (static) so_module (static) watchdog_module (static) http_module (static) log_config_module (static) logio_module (static) version_module (static) unixd_module (static) access_compat_module (shared) alias_module (shared) auth_basic_module (shared) authn_core_module (shared) authn_file_module (shared) authz_core_module (shared) authz_host_module (shared) authz_user_module (shared) autoindex_module (shared) deflate_module (shared) dir_module (shared) env_module (shared) filter_module (shared) mime_module (shared) mpm_event_module (shared) negotiation_module (shared) proxy_module (shared) proxy_balancer_module (shared) proxy_http_module (shared) reqtimeout_module (shared) setenvif_module (shared) slotmem_shm_module (shared) status_module (shared) Results when I run 'ab -k -n 10000 -c 1000 http://vm_host_ip_address:8010/' with no balancer... Finished 10000 requests Server Software: Apache/2.4.41 Server Hostname: 192.168.68.210 Server Port: 8010 Document Path: / Document Length: 97098 bytes Concurrency Level: 1000 Time taken for tests: 24.029 seconds Complete requests: 10000 Failed requests: 5526 (Connect: 0, Receive: 0, Length: 5526, Exceptions: 0) Keep-Alive requests: 8938 Total transferred: 870844342 bytes HTML transferred: 868062523 bytes Requests per second: 416.16 [#/sec] (mean) Time per request: 2402.908 [ms] (mean) Time per request: 2.403 [ms] (mean, across all concurrent requests) Transfer rate: 35391.87 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 22 144.2 0 1039 Processing: 0 1087 2291.1 451 18504 Waiting: 0 1207 2615.1 426 18470 Total: 0 1109 2372.3 451 19514 Percentage of the requests served within a certain time (ms) 50% 451 66% 585 75% 678 80% 764 90% 1868 95% 7315 98% 10098 99% 11156 100% 19514 (longest request) Finished 10000 requests No changes on vhost configuration file... <VirtualHost *:80> ServerAdmin webmaster@localhost DocumentRoot /var/www/html ErrorLog ${APACHE_LOG_DIR}/error.log CustomLog ${APACHE_LOG_DIR}/access.log combined </VirtualHost> Results when I run 'ab -k -n 10000 -c 1000 http://vm_host_ip_address:8010/' with balancer configured... Finished 10000 requests Server Software: Apache/2.4.41 Server Hostname: 192.168.68.210 Server Port: 8010 Document Path: / Document Length: 97098 bytes Concurrency Level: 1000 Time taken for tests: 15.527 seconds Complete requests: 10000 Failed requests: 834 (Connect: 0, Receive: 0, Length: 834, Exceptions: 0) Keep-Alive requests: 9166 Total transferred: 892851836 bytes HTML transferred: 890000268 bytes Requests per second: 644.04 [#/sec] (mean) Time per request: 1552.701 [ms] (mean) Time per request: 1.553 [ms] (mean, across all concurrent requests) Transfer rate: 56155.42 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 22 146.6 0 1038 Processing: 0 657 1668.1 122 13453 Waiting: 0 752 1883.8 121 13453 Total: 0 679 1763.1 122 14476 Percentage of the requests served within a certain time (ms) 50% 122 66% 234 75% 330 80% 402 90% 1657 95% 4987 98% 7221 99% 8733 100% 14476 (longest request) Finished 10000 requests I replaced the apache vhost config file with... <Proxy balancer://mycluster> BalancerMember http://vm_host_ip_address:8011 BalancerMember http://vm_host_ip_address:8012 </Proxy> ProxyPreserveHost On ProxyPass / balancer://mycluster/ ProxyPassReverse / balancer://mycluster/ The index.html file is a 90KB plain text file for both node1 and node2 I'm missing something? The problem is the way virtualbox handles this network configuration and in a real world the results would be different? -- Marc Serra -- Manxa 1876, S.L. * Ctra. Les Tries, 85. 17800 Olot (Girona)**Tel. 972 27 45 30 Fax 972 27 45 32* * Manxa Industrial | *Coneix més aquí <http://www.manxaindustrial.com> * Manxa Ferros | *Coneix més aquí <http://www.manxaferros.com/> * Manxa Ferreteria i Parament de la Llar | *Coneix més aquí <https://www.manxabricolatge.com> ** -- El contingut d’aquest correu electrònic i els seus annexos és estrictament confidencial. En el cas que no siguis el destinatari i hagis rebut aquest missatge per error, preguem que ho comuniquis al remitent i procedeixis a la seva eliminació, sense difondre, emmagatzemar o copiar el seu contingut. Imprimeix aquest correu només si és necessari. El contenido de este correo electrónico y sus anexos es estrictamente confidencial. 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