HandleHttpRequest runs twice if requested from browser (Chrome, Firefox)

Hi,

I need to handle an HTTP request and I need to respond an HTML file with NiFi.

My flow is like

HandleHttpRequest -> ExecuteSQL -> HandleHttpResponse.

I need to query our database to show proper HTML result.

My problem is HandleHttpRequest runs twice for each request when triggered by browsers such as Chrome, Firefox. HandleHttpRequest runs once if I use Postman or SoapUI.

I've tried to eliminate the second call by using HashContent and DetectDuplicate but it makes some of our requests fail. I've investigated the issue and I've found that Chrome and Firefox creates an additional request for displaying favicon and sometimes some other reasons. (Link)

I need to find real request and I need to eliminate other requests. The real request can be the second one depending on the browser status. Browser decides when to create new requests and their orders.

So, my question is how can I run my flow exactly one time when user creates request from their browser? Because I do some operations on the database and second call ruins these operations.

Thanks.