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You can change this to any path you want in ehcache.xml and it applies globally.

The ColdFusion documentation for the cacheSetProperties() tag currently shows that diskstore is a valid option:

http://help.adobe.com/en_US/ColdFusion/9.0/CFMLRef/WSc3ff6d0ea77859461172e0811cbec22c24-7c18.html

My testing, however, has shown that is not working in the shipping build of ColdFusion 9. Try the following example (you'll need to create a directory off your root, c:/temp):

Before:

After:

If you run this code and check the c:/temp directory you should find it empty. Check your jave temp directory (c:/windows/temp on wintel) and you'll see that the files are still written there showing that the default value in ehcache.xml is being used and not the value being set in the cacheSetProperties() function.

The obvious action is to remove this attribute from the documentation until it can be implemented in a later version of ColdFusion. I would like to see it implemented, though, as I think it's useful to be able to set the diskstore location programmatically.

CacheGetMetadata() Returns both Cache Wide and Item Specific Metadata (ER 81842)

What this actually returns to you is a structure with two sets of information:

Cache_hitcount and cache_misscount apply to the overall cache. In other words, how many hits and misses the entire cache have received. The rest of the keys returned in the structure apply to the item passed in to the cacheGetMetadata() function.

I see a couple of potential issues with how this has been implemented. What I think we really need is two separate functions here. The existing cacheGetMetadata() should return just the metadata that is specific to the item passed to the function, not metadata on the entire cache. I would expect a separate function to retrieve metadata for the cache itself. To avoid confusion, I'd call the new function something like cacheGetStats(). In my mind it would return the cache_hitcount and cache_misscount that are currently returned by the cacheGetMetadata() function. It would also return a whole lot more that's available from ehcache but not exposed to ColdFusion – things like the total number of items currently in the cache, total size in bytes of all of the items in the cache, etc.

An Alternate Proposal for Additional ehcache Functionality (ER 81843)

Inability to Specify Cache Key in Functions (ER 81844)

This creates a cache region at runtime called customCache. Getting, putting and flushing the cache are all supported from the cfcache tag. However, it's not currently possible to use any of the caching functions to operate on the custom cache region because there is no way to specify which cache region you want to use – the functions always apply to the default object or template cache.

I'd like to propose adding an optional attribute to all cache functions to allow a developer to pass in a custom cache region (key) for the function to operate against where applicable.

Naming Inconsistencies for Removing Cache Items (81845)

Using a function instead, you use cacheRemove():

Fragment Cache Gotcha (bug 81846)

Consider the following example:

If you execute this, you'll get some output as well as a dump of all of the cached items in the template cache (getalltemplatecacheids is an undocumented function). At this point, there are two items in the cache:

Now say you weren't happy that the two lines of output on your page were all run together and you wanted to put a line break between each one. You might modify your code and add in a simple paragraph tag or line break like so:

Go ahead and run the code once you've inserted the

tag. What you'll now see is that you have three items in the cache:

What's happening is that ColdFusion is using the position of the code in your page as part of the ID for the cached item. When you inserted the

tag, the position of the fragment you cached also changed by moving down a few lines, and ColdFusion assumed you had added a new page fragment that you wanted to cache.

This may or may not be a big deal to people as CF will still pull the correct cached item every time. The gotcha is that if you have a lot of caching going on, and you're making a lot of changes in a development environment, it's possible to fill your cache up with a lot of junk pretty quickly.

I'm not making any statements on how this feature was implemented - I just want to make people aware of how the template cache works under the covers since it's not documented and if people are paying attention when they are developing they might see some things with the template cache that don't make sense if they don't know how it works.

cacheSetProperties() and cacheGetProperties() are Missing Configurable Parameters (ER 81847)

diskSpoolBufferSizeMB: This is the size to allocate the DiskStore for a spool buffer. Writes are made to this area and then asynchronously written to disk. The default size is 30MB. Each spool buffer is used only by its cache. If you get OutOfMemory errors consider lowering this value. To improve DiskStore performance consider increasing it. Trace level logging in the DiskStore will show if put back ups are occurring.

clearOnFlush: It determines whether the MemoryStore should be cleared when flush() is called on the cache. By default, the MemoryStore is cleared. Useful is you want to back up a cache to the file system without clearing the MemoryStore.

diskExpiryThreadIntervalSeconds: The number of seconds between runs of the disk expiry thread. The default value is 120 seconds.

I'm not sure why these were left out but it would be nice if they were also included in the configurable properties using ColdFusion functions.