Using Solr's admin web interface, we can set various log levels. Go to the admin interface by typing the following URL:
http://localhost:8983/solr/
You should see the following admin screen:
You will see that on the left-hand side, there is a Logging option. Click on it and there will be a submenu item called Level, which will open up the following screen:
Here, we can set the logging level for many different log categories in a hierarchical order. For example, let's say I want to set org.apache.http.conn.ssl to log level and set all the subcategories under it to debug level; I will click on the edit icon next to ssl, as shown here:
This will open up a small popup with various log levels that we can set.
Various log level settings are listed here:
- ALL: Logs everything
- TRACE: Logs everything but leaves the least important messages
- DEBUG: Logs debug-level messages
- INFO: Logs info-level messages
- WARN: Logs all warning messages
- ERROR: Logs all errors
- FATAL: Logs every fatal message
- OFF: Removes logging
- UNSET: Removes the previously selected logging option
You can also set the log level using an API:
curl -s http://localhost:8983/solr/admin/info/logging --data-binary "set=root:WARN"
The preceding curl command sets the root category to the WARN level.