Filter

Enable Sniffy filter in web.xml

<filter>
    <filter-name>sniffer</filter-name>
    <filter-class>io.sniffy.servlet.SniffyFilter</filter-class>
    <async-supported>true</async-supported>
    <init-param>
        <param-name>enabled</param-name> (1)
        <param-value>true</param-value> <!-- default: true -->
    </init-param>
    <init-param>
        <param-name>exclude-pattern</param-name> (2)
        <param-value>^/vets.html$</param-value> <!-- optional -->
    </init-param>
    <init-param>
        <param-name>inject-html</param-name> (3)
        <param-value>true</param-value> <!-- default: true -->
    </init-param>
    <init-param>
        <param-name>inject-html-exclude-pattern</param-name> (4)
        <param-value>^/peds.html$</param-value> <!-- optional -->
    </init-param>
    <init-param>
        <param-name>monitor-socket</param-name> (5)
        <param-value>false</param-value> <!-- default: true -->
    </init-param>
</filter>
<filter-mapping>
    <filter-name>sniffer</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

Allows disabling the Sniffy filter in web.xml
Allows excluding some of the request URL’s from Sniffer filter
Enables injection of Sniffy toolbar to HTML. If disabled the html remains untouched. You still can get the number of executed queries from Sniffy-Sql-Queries HTTP header.
Allows excluding of Sniffy toolbar injection to some of the request URL’s
Allows disabling socket monitoring functionality; will also disable fault tolerance testing features

Apart from obvious false and true values, you can set inject-html and 'enabled' parameters to a system value. It will act as described in table below:

Table 1. Sniffy Filter Configuration
-Dio.sniffy.filterEnabled or IO_SNIFFY_FILTER_ENABLED	enabled filter init param	Effective value
null	absent	true
true	absent	true
false	absent	false
null	false	false
true	false	false
false	false	false
null	true	true
true	true	true
false	true	true
null	system	false
true	system	true
false	system	false

Similar rules are applied to inject-html filter parameter