Modern UI logging

The modern UI logs capture error output from all modern UI endpoints (Funnelback URLs that start with /s/). This includes the HTML, JSON and XML endpoints as well as the auto-completion, cache, all results and recommender endpoints.

Log files

Logging is captured at the search package level. This means that log messages from all results pages in a search package will be captured in the same set of log files.

To access the modern UI logs for a results page, navigate to the details page for the parent search package and select the browse log files option from the tools section.

The modern UI logs are located under the collection log files heading:

  • modernui.Public.log: contains messages logged via the public search interface (accesses that are received on the public HTTP and HTTPS web server ports).

  • modernui.Admin.log: contains messages logged via the admin search interface (accesses that are received on the admin HTTPS web server ports).

If you are debugging make sure you check the URL that you are accessing Funnelback on and view the appropriate log file.

Log levels

The following log levels are defined in log4j:


The modern UI default log level is:

  • INFO: for com.funnelback classes and

  • WARN: for everything else.

Only log messages at the specified log level or higher will appear in your log files. e.g. for non-com.funnelback classes you will only see warn, error or fatal log messages unless you increase your log level.

Increasing the log level for a request

A special HTTP header can be passed in with a search request to increase the log level for the duration of that HTTP request. This enables you to perform debugging on modern UI related requests. This can be used to debug search templates, plugins and related functionality.

Passing in the x-funnelback-request-detailed-logging: true request header when making a request to a modern UI endpoint (any Funnelback URL starting with /s/) will increase the log level for that request to TRACE level.

You can use a tool such as the ModHeader browser extension to send this additional HTTP header. Don’t forget to turn this off when you finish testing though otherwise your log files will be filled with lots of additional logging.