Confluence throws 'Preemptive authentication requested but no default proxy credentials available' when accessing pages using outbound proxy
Platform notice: Server and Data Center only. This article only applies to Atlassian products on the Server and Data Center platforms.
Support for Server* products ended on February 15th 2024. If you are running a Server product, you can visit the Atlassian Server end of support announcement to review your migration options.
*Except Fisheye and Crucible
Problem
When accessing pages that contains content obtained from an external service, the following warnings appear in atlassian-confluence.log:
2017-03-13 16:55:33,585 WARN [http-nio-443-exec-11] [apache.commons.httpclient.HttpMethodDirector] authenticateProxy Required proxy credentials not available for BASIC <any realm>@proxy.xxx.com:3128
-- referer: http://localhost:8090/display/TEST | url: /rest/calendar-services/1.0/calendar/events.json | traceId: bd997c289a6e64a2 | userName: admin
2017-03-13 16:55:33,585 WARN [http-nio-443-exec-10] [apache.commons.httpclient.HttpMethodDirector] authenticateProxy Preemptive authentication requested but no default proxy credentials available
-- referer: http://localhost:8090/display/TEST | url: /rest/calendar-services/1.0/calendar/events.json | traceId: 194954d8084x97e7 | userName: adminThe page can be loaded fine and the content appears correctly and as expected. However, the warnings above still appear in the logs as noise.
Diagnosis
Confluence is configured with an outbound HTTP/HTTPS proxy as per the documentation below, but no credentials (http.proxyUser and http.proxyPassword) is required for the outbound proxy.
Workaround
To ensure the warnings no longer appear in your logs, include the following properties into your Java options (setenv.sh / setenv.bat) or catalina.properties and restart Confluence. There should be no values passed as no credentials are required.
http.proxyUser=
http.proxyPassword=
https.proxyUser=
https.proxyPassword=