Allow to view performance metric and monitoring events generated by the backend.

see the installation guide

$ vi front.config.json

{
        "db" : 
        {
                "host"   : "localhost", /*   MySQL database connection string */
                "dbname" : "watcheddb", /*   MySQL database name */
                "user"   : "watched",   /*   MySQL login */
                "pass"   : "watched"    /*   MySQL password */
        },
        "displayErrorDetails" : false,
        "addContentLengthHeader" : false
}

The frontend doesnt check for changes in its configuration file, so after each edit you'll need to restart it.