Magento Cache Warming - magento

Question

My team and I are rapidly launching new stores and views on Magento Enterprise Edition but we're running into an issue with caching. To be clear, the caching part itself works great. We have several complex products that take about 17 seconds to build, but after its cached the pages loads in 300ms, which is awesome! Unfortunately, if we clear the cache under any serious load (high traffic) we seem to be experiencing a cache miss storm, where every page request is trying to populate the cache, causing our webhead to stall out with load averages above 50.
Do you have any suggestions for avoiding this? Are there documented best practices for pre-warming a cache for new code deployments or even just content and configuration changes?
This could be related, so I'll include it: After clicking the button to refresh the cache and before the refreshing process is complete most pages on the front end die with 500 error codes and seemingly random error messages. Any idea what might cause that?

Answer 1

I implemented a solution to warm up a cache after a CMS Block is saved. You may take the inspiration of this solution to do the same for different cases (product save, CMS block, CMS Page, Category Save, etc)
This piece of code can be triggered after a CMS Block save by using an observer cms_block_save_after:
/**
* Clean targeted cache block and warmup if content is provided
*/
public function clearBlockHtmlCache(Varien_Event_Observer $observer)
{
$block = $observer->getEvent()->getObject();
$id = $block->getCacheKey();
// Remove only specific cache block
Mage::app()->getCacheInstance()->getFrontend()->remove(strtoupper($id));
// no print, it's ok just warmup cache with filters processing
$block->toHtml();
}