Why is CFTHREAD not running query and creating a file? - coldfusion

Question

I have a function that should check the date of a file. If the file is greater than sixty seconds, a query should run and create a new file. The query takes sixty seconds to run.
This process works perfectly when it's not wrapped in a CFTHREAD. When CFTHREAD is used, nothing seems to happen. I get no errors. What I expect to see, is a new file being made. I never see that new file.
Where should I look for an error? What am I missing? Why is CFTHREAD not working?
<!--- GET CATEGORIES --->
<cffunction name="getCategories" access="remote">
<cfscript>
LOCAL.MaxFileAge = 60;
LOCAL.MaxFileUnits = 's';
// THE FILE
LOCAL.TheFileDaily = "#VARIABLES.JSDir#\#VARIABLES.DayMonth#-categories.json";
// THE FILE DOES NOT EXIST
if (fileExists(LOCAL.TheFileDaily) == false) {
LOCAL.MakeNewFile = true;
// THE FILE EXISTS
} else {
// GET THE DATE OF THE FILE
LOCAL.LastModified = getFileInfo(LOCAL.TheFileDaily).LastModified;
// GET FILE AGE
LOCAL.FileAge = dateDiff(LOCAL.MaxFileUnits, LOCAL.LastModified, now());
// FILE IS OLD
if (LOCAL.FileAge > LOCAL.MaxFileAge) {
LOCAL.MakeNewFile = true;
} else {
LOCAL.MakeNewFile = false;
}
}
</cfscript>
<cfif LOCAL.MakeNewFile eq true>
<cfthread action="run" priority="HIGH">
<cfquery name="Q">
SELECT Stuff
FROM Tables
</cfquery>
<!--- MAKE THE DAILY FILE --->
<cffile action="write" file="#LOCAL.TheFileDaily#" output="#serializeJSON(Q)#">
</cfthread>
</cfif>
</cffunction>

Answer 1

You can't write to and share the local scope to a seperate thread, you need to share them via the request scope (request is the ideal scope for this as developers have very tight control over what data is contained within). You might try something like this:
Create a struct within the request scope and write to that.
In fairness, only variables you need to transfer need be in the request scope's struct. This is just a generic update because I don't know what the contents of your CFTHREAD really looks like. In this case, it actually looks like TheFileDaily is the only variable you're sharing, so that would be the only thing that needed to be in the request scope.
<!--- GET CATEGORIES --->
<cffunction name="getCategories" access="remote">
<cfscript>
request.lData = StructNew();
request.lData.MaxFileAge = 60;
request.lData.MaxFileUnits = 's';
// THE FILE
request.lData.TheFileDaily = "#VARIABLES.JSDir#\#VARIABLES.DayMonth#-categories.json";
// THE FILE DOES NOT EXIST
if (fileExists(request.lData.TheFileDaily) == false) {
request.lData.MakeNewFile = true;
// THE FILE EXISTS
} else {
// GET THE DATE OF THE FILE
request.lData.LastModified = getFileInfo(request.lData.TheFileDaily).LastModified;
// GET FILE AGE
request.lData.FileAge = dateDiff(request.lData.MaxFileUnits, request.lData.LastModified, now());
// FILE IS OLD
if (request.lData.FileAge > request.lData.MaxFileAge) {
request.lData.MakeNewFile = true;
} else {
request.lData.MakeNewFile = false;
}
}
</cfscript>
<cfif request.lData.MakeNewFile eq true>
<cfthread action="run" priority="HIGH">
<cfquery name="Q">
SELECT Stuff
FROM Tables
</cfquery>
<!--- MAKE THE DAILY FILE --->
<cffile action="write" file="#request.lData.TheFileDaily#" output="#serializeJSON(Q)#">
</cfthread>
</cfif>
</cffunction>
Useful sources:
Working with Threads
Adam Cameron's post on the topic