Core/Loader 346 Issue

It sounds like the issue is due to writing to the database and not read due to high traffic of visits. So caching the database would not really help here. (if the writes are the problem, caching is still always good practice for reading whenever possible)

How many is "several data feeds"? And are you triggering them all at the same time? If you do, I highly recommend to change that to start with to run one or two script at a time. Implement a locking, an example here https://stackoverflow.com/questions/5428...-lock-safe

Other things to consider could be.

• Check execution time for the scripts. If they take more the 3 min to complete, a new instance will start before the old is completed, and that way use up more and more resources. Again, locking feature is good here.
  
• Check what MySQL engine you use. For write heavy databases, InnoDB is recommended as it only do row level locking while the default MyISAM do table level locking on writes. Here is some good information on this https://stackoverflow.com/questions/1567...and-innodb
  
• Maybe upgrade to MySQL replication Master - Slave setup. More info about that http://www.rackspace.com/knowledge_cente...asterslave But this is a project of it self to update all code to support it.
  
• Also, what type of data are the feeds returning. XML or JSON formatted? I would recommend JSON if you don't already use it, and the feeds supports it, as it is faster in most cases to decode in PHP (https://stackoverflow.com/questions/4288...ml-parsing)