Red Hat Bugzilla – Bug 970473
visit page duplicates.cgi and 502 Proxy Error happened
Last modified: 2014-07-21 00:31:55 EDT
Created attachment 756625 [details] screenshot for comment0 Description of problem: visit page duplicates.cgi and 502 Proxy Error happened Version-Release number of selected component (if applicable): prod env version 4.4-3.3 How reproducible: always Steps to Reproduce: 1. click 'Most frequently reported bugs' in 'Most Common Actions' section on homepage. 2. check the result. Actual results: 502 Proxy Error The proxy server received an invalid response from an upstream server. The proxy server could not handle the request GET /duplicates.cgi. Reason: Error reading from remote server Expected results: duplicates.cgi page would be shown up. Additional info: screenshot attched.
more infos for this bug: tried for 4 times on prod env, always happened this problem as comment0. tried for 3 times on QE test env, 2 times correct but one time met errors like: Internal Server Error The server encountered an internal error or misconfiguration and was unable to complete your request. Please contact the server administrator, sysadmin-engops@redhat.com and inform them of the time the error occurred, and anything you might have done that may have caused the error. More information about this error may be available in the server error log. Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
This behaviour still happens on the production server, taking around two minutes to show the 502 error page, but does not cause a long query timeout notification to be sent to the admin list.
This issue appears to have been fixed by the recent migration to the new webservers and mod_perl. Now, visiting https://bugzilla.redhat.com/duplicates.cgi takes about 15 seconds the first time and about 5 seconds on subsequent visits (the speedup being due to the caching performed by both the database and mod_perl). This suggests that the problem was on the webserver side, which would explain the previously noted lack of a long query timeout notification from the database (and the apparent lack of related entries in the slow query logs). Tested using Fedora 20 and Firefox 30.0.