call_user_func_array randomly throwing warning: "Unable to call parent::func"

[budfroggy]

I am seeing something really weird, and I am at a loss as to how to debug it.

I have a production system that serves up a couple million pages a month, and it includes a comment system. I have a memcache caching layer on top of the database, so everything first checks the cache, and if it finds nothing, goes to the database.

 

The simplified call stack looks like this:

 

Comment->load( )

CacheLayer->getCommentData( $id )

CacheLayer->get( $function, $params )

  call_user_func_array( array( 'parent', $function ), $params )

 

Now, the problem is as follows:

call_user_func_array returns: Warning: call_user_func_array() [function.call-user-func-array]: Unable to call parent::getCommentData()

for certain IDs consistently, but works fine for others, i.e. IDs 13596, 5221, and about 5 others consistently fail at this point, whereas the thousands of other comments work just fine.

 

I tried load the entire database into our QA environment to replicate it, but I am not seeing the same problems.

 

I am at a complete loss. Any and all help would be much appreciated.

 

Thanks