I am working on a performance analysis for a client, some page requests need to do a cfhttp call, I had the thought to use cfthread for the http call, so that other processing could happen in parallel.

Curious about this, I wrote some simple scripts to test, first my control script:

<cfhttp url="http://google.com/robots.txt" method="get"></cfhttp>
<cfdbinfo datasource="cfdocexamples" name="tables" type="tables">
<cfoutput query="tables">
    <cfif Left(tables.table_name, 3) IS NOT "SYS">
        <cfquery datasource="cfdocexamples">
            SELECT * FROM #tables.table_name#
        </cfquery>
    </cfif>
</cfoutput>

Next my threaded script:

<cfthread name="doit">
  <cfhttp url="http://google.com/robots.txt" method="get"></cfhttp>
</cfthread>
<cfdbinfo datasource="cfdocexamples" name="tables" type="tables">
<cfoutput query="tables">
    <cfif Left(tables.table_name, 3) IS NOT "SYS">
        <cfquery datasource="cfdocexamples">
            SELECT * FROM #tables.table_name#
        </cfquery>
    </cfif>
</cfoutput>
<!--- make sure thread is done processing --->
<cfthread action="join" name="doit" />

I then used Apache Bench to create some concurrent load on the scripts:

As you can see when you limit the number of threads that can be created you create a bottle neck in your application (this is why I wrote an entry when CF8 came out titled CFThread Don't Abuse It. You might wonder why I choose maxthreads=2 for one of the tests... If you are running Standard Edition that is the most concurrent threads you are allowed to create with cfthread, for a situation like this it can really hamper performance.

This test also illustrates how using threads (with the correct settings) can increase performance.