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Clearing the ColdFusion template cache programmatically

Note: This blog post is from 2012. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.
I was asked today how one might clear the template cache ColdFusion template cache programmatically, as opposed to clicking the button in the CF Admin (Caching) page. The good news is that pretty much anything done in the CF Admin can be done programmatically, via the CF Adminapi, since CF 7. And there is in fact an AdminAPI method to clear the template cache. I'll show the code in a moment.

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Comments
Good tips there Charlie.

Just a follow up, if you have a multi instance environment, with trusted cache on, you need to call the clearTrustedCache() on each instance.

The way we have this done this, is by having an admin extension page (like you suggest) in the CF administrator on the CFusion instance. This calls a CF page per instance to clears its local trusted cache. Works really well and is a one stop button to clear all caches on X amount of instances.
# Posted By Tom Jenkins | 12/14/12 5:15 AM
@Tom, yep, and just to be clear, this is why I'd said that the method cleared the entire template cache "across all templates and applications on the CF *instance*" (emphasis added). I suppose I could have added, "and only that instance, if you have multiple instances", but your comment now will make that clarification. :-)

And yes, fair point that if you have a cluster of instances, sharing the same code base, then if you needed to clear the template cache on one, you'd likely need to clear it on all instances in the cluster. Thanks for pointing it out.
# Posted By Charlie Arehart | 12/14/12 10:10 AM
@Charlie,

Have you ever run into an issue where the template cache is so large that it brings a site down?
# Posted By Steve Withington | 1/23/13 3:23 PM
Found this article from the googles. Works great.

But worried about placing a template somewhere that has the CF Admin password. Is there a way to protect that? Or a way to specify a user account other than the 'admin', say one that had less privileges than 'admin'?

Thanks...Rick...
# Posted By Rick | 1/21/14 4:35 PM
@Rick, what I do is treat it like any other sort of password-protected CF code: i check if a cfadmin var in the session scope exists: if not, I prompt for it, and I use that in the code.

I realize I just showed the password being stored in code above. I was just offering the simplest example and assumed people could/would modify it to suit their tastes. But glad you asked, and hope this comment will suffice to get you/others going on this point.
# Posted By Charlie Arehart | 1/21/14 4:51 PM
@Charlie : thanks for your quick response to an old thread.

I have added code for a login form before the code is entered (wandered into the adminapi docs to figure out how to specify a user other than 'admin'; was quite proud of myself). So that part is working.

But I notice that the number of entries returned by the directorylist command are nowhere near the number of CFM/CFC files on the site. My count stops at about 862.

I have set the requesttimeout setting to "120", but that doesn't help. Can you think of any reason why directorylist is not returning all of the files into the array?

Thanks.
# Posted By Rick | 1/22/14 3:43 PM
@Rick, sorry for the delay in responding to this one. So about "the directorylist command", do you mean the CFML function? Or might you be referring to something in the admin API (since that was also being discussed here)?

As for it not returning all files, and you wondering if a timeout is impacting things, I'd say that if you hit a timeout before it finished, you'd get an error not a low number. So I suspect something else is at play for you.

But first I wonder: why are you doing a directorylist in the first place? Is it that you want to have CF look at ALL files in a folder? Just note that CF10 adds that as a feature of the cleartrustedcache method. But maybe you are wanting to look at all files in a folder and only get those that are updated recently.

Anyway, if indeed you are using the directorylist function, and if the "low" number returned is because you are counting all files in that folder and any subfolders, it could be that the function is not recursing into subfolders. There is an argument to control that. It's not clear from the docs what its default is.

Hope that helps.
# Posted By Charlie Arehart | 2/4/14 7:07 PM
Hey Charlie,

Whenever we are using composition as a style for our cfcs, we are finding that cfcs that are instantiated in the "parent" cfc will not clear from the trustedcache when clearing by file or by the entire directory. The only way we can get this to work is to clear then entire trusted cache.

parent.cfc
function init()
this.exampleChild = new child();
this.exampleChild.newFunctionJustUploaded()

child.cfc
function newFunctionJustUploaded()
return void


We would upload changes to child.cfc, clear child.cfc and parent.cfc and then parent.cfc would bomb stating that newFunctionJustUploaded() is not defined. We try programatically clearing the trusted cache by file and directory repeatedly -- no luck.

The funny thing is, we can try to recreate a test case, but the test never succeeds in demonstrating the problem! Our test cases have zero traffic, so that's the only conclusion we can make. Something under the hood does not allow child CFCs under a composition "chain" to recompile when programatically clearing the trusted cache, even when we clear all files in the composition chain/or the entire directory when there is a moderate amount of traffic to those files.

Unfortunately, the performance hit when clearing the whole trusted cache is pretty substantial, so we try to avoid that whenever possible.

I'm not sure if this comment is a question or a comment, but there it is. This post comes up in google as a top result.
# Posted By Brian | 4/24/14 9:44 AM
Odd that under CF11 our active webservice no longer appear in the listing under the admin. I confirmed that I am on the right admin that is connected to the iis site we are hitting. strange
# Posted By Alex | 4/16/15 1:49 PM
Alex, since CF10, you will not find that CF adds web services to the list in the CF admin anymore. You can add them, but don't need to.

That said, this blog entry is not at all about web services, or CF11. It seems an odd place for you to have raised this issue. :-) FWIW, if you look on the right, I do have a web services category, currently with 8 current entries, and one of them may be a better place to raise such questions (though for now, if you have only a closing comment on this, feel free to add it here).
# Posted By Charlie Arehart | 4/16/15 2:08 PM
We skipped 10 and when to 11 :) I will use the correct section in the future thanks!
# Posted By Alex | 4/16/15 2:15 PM
Hey Charlie,

I have a question in regards of CF9, recently I added a new Jar file to the C:\ColdFusion9\cfusion9_home\WEB-INF\lib folder, this new jar is just a Java 1.5 library with some new functionality, I was doing some tests, but after that the Jar file was no longer necessary and I delete it.

But my application still has visibility of the classes I had on that Jar, I'm facing some caching issues, have you ever seen the same issue ? if so, what do you recommend ? do you know how to clear this kind of java classes and clear this cache ? I tried already from the Admin console but nothing works.

Any help will be very appreciated.
Thanks in advance.
# Posted By Ricardo P. Silva | 2/24/17 10:02 AM
Ricardo, that's an interesting question with a lot more behind it than meets the eye, potentially. So this is a long comment, but I hope to get you to your solution.

1) Let's clarify first what you mean by "my application still has visibility of the classes I had on that Jar".

2) And second, when you say you "deleted" the jar, do you really mean you deleted the file (from that CF lib folder), and restarted CF (which would be required for it to be "gone" from CF)? Or might you mean only that you simply renamed the jar file?

I will say that it sounds like you maybe just renamed it. This is a frequent cause of confusion, because folks think that the name of the file is significant. But to Java, it is not. AT ALL. Java looks in ALL jars and classes (in its classpath) to find the first which matches the class (and optionally package) name requested by the Java code.

3) So let's also clarify what you're "seeing". When you say "my application still has visibility of the classes I had on that Jar", do you mean that you can write code that calls those classes and they work?

4) And even if you would say you really did DELETE the jar file, are you 100% sure that the class you're requesting isn't found by some other Java jar (or class file), that perhaps comes with CF or the underlying CFML server (Jrun in your case)?

5) Or do you perhaps mean that you are running some CFML code which is failing because it refers to these classes, which you feel were deleted, and it's failing because it can't find them?

You see how your problem can be any of a number of things.

6) Even if it's this last issue, of an error arising because you have code still trying to call the classes that you feel you deleted, let me clarify first that you may well still have such CFML code calling such classes. :-) But I'll assume you have confirmed that's not the case.

6a) If your point is that you DO see the errors from pages "still accessing it", and you think you HAVE edited them to remove such access, that's then a different matter. And perhaps that's how you think this challenge somehow related to to the subject of this blog post.

6b) First, if you thought it may be that CF is "caching in the template cache" such code of yours which had referred to this Java class (you removed), but you feel you removed that code referring to it, it's worth noting that if you restart CF, that clears the template cache. Did you do that? did it help?

6c) If you did and it did not (and this latter line of questioning is what you think is going on), the only other possibility I readily see is that perhaps you have CFML classes which have been *saved* (per the "save class files" option I allude to above--but don't elaborate on, as it's beyond the scope of this post). It MAY be possible that you could have saved class files that were from a version of your CFML back when it was still referring to this now-removed Java class (and somehow your edited file is NOT overriding that saved class file. There are reasons, but let's not devolve into that discussion here.) The problem is that it's hard to delete a specific cfclass file for a given CFML template.

6d) In most cases, people with some issue like this (this latter point I'm making, where you once had code referring to a java class, but you removed it, and yet still see errors like it's trying to refer to it) have simply resorted to deleting all their cfclass files (in the wwwroot\WEB-INF\cfclasses folder). That's often overkill, so don't do it unless you're sure that not of the other proposals I make above work first.

Let us know how it goes. I have given numbers to the paragraphs above (in a hierarchy where appropriate), if you may want to easily refer back to a point in any reply.

(And if you remain stuck, I'm confident I could resolve this in a consulting session, in perhaps less than 15 minutes. More at the www.carehart.org/consulting.)
# Posted By Charlie Arehart | 2/24/17 11:32 AM
@Charlie, hello,

Thanks for answering me, I'm going to answer point by point.

1) I was using that java 1.5 Jar with CF9, in other words, I'm calling Java from CF9 this way and was working fine:

<cfset Request.whateverJavaVar = Createobject("java", "com.company.whatever.WhateverClassName") />

Even now when the JAR file is not present into the lib folder and I have restarted the CF9 app server several times.. the Jar is gone and I still do see the CF server still has visibility of the "WhateverClassName" class,.. I was specting an error, but no, no errors calling WhateverClassName.someMethod(), that's why I think the classes were cached or something, that's what I meant when I said "my application still has visibility of the classes I had on that Jar".

2) I actually deleted the JAR file.

3) Yes. and it is crazy, seems to me, the DF server has loaded the definitions of those classes somewhere and I can't clean/erase them.

4) exactly, I'm 100% sure those classes does not exist somewhere else, I was coding those classes from scratch.. there is no way I can have another class name with exactly the same signature into the same package somewhere else.

5, 6, 6a do not apply.

6b) I tried to clear the cache from the admin page, nothing works.

6c) this might be the root cause of the issue, I'm not sure, CF could be loading the definition of those java classes somewhere, and I don't know where.

6d) for me is located at C:\ColdFusion9\cfusion9_home\WEB-INF\cfclasses and it is empty.

Before posting this comment, I did test again, and my local CF9 application server is "reading" this class that is supposed does not exist.

I'm not sure if I mentioned before this is happening on my local environment (my PC) and I do not want to propagate this issue to the actual DEV, QA and PROD environments :o(
# Posted By Ricardo P. Silva | 2/24/17 1:07 PM
OK, Ricardo. Let's try some other things, then. (To be clear, no, I don't think there's some bug here, just a case of you having the class somewhere ELSE than that lib location.)

1) So you said you had put the jar in CF's WEB-INF\lib folder, from which you deleted it. Well, note that there is a sibling to that called classes (WEB-INF\classes), where one can put a .class file (.jars typically go in lib, .class files typically go in classes). CF automatically can load classes or jars from both. Worth double checking to see if you or anyone put a version of your mystery class there.

2) The CF admin also lets you point to STILL OTHER locations to load classes and/or jars. See the "java & vm" page, and its "coldfusion class path" field. Anything there? If so, check those folders.

3) Better still, the CF admin also has a page that prints out ALL the jars it has loaded. See the "Settings Summary" (right under "java & jvm"), and its "CF Server java class path" field, and see if perhaps there's a folder you recognize loading the jar in question (from somewhere not identified above).

4) Finally, you may be able to get the location of the JAR using this code:

<cfdump var="#classLoader.forName("yourpackage.youclassname").getProtectionDomain().getCodeSource().getLocation().tostring()#">

That should print out the location but under some circumstances it may not work. Just to see if it works with a class that CF always has, you could try this:

<cfdump var="#classLoader.forName("macromedia.jdbc.MacromediaDriver").getProtectionDomain().getCodeSource().getLocation().tostring()#">

That reports (on a CF11 server):

C:/ColdFusion11/cfusion/lib/macromedia_drivers.jar

Let us know how you go.
# Posted By Charlie Arehart | 2/24/17 2:23 PM
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