Can prefetch caching help me solve, first page request for every page is slow?

Question

for some reason the first request for every single pages on our site is pretty slow. 2nd hit and subsequent are good.

Thinking of applying a patch for CD per below:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <cacheSize>500MB</cacheSize>

  <template desc="mysitetemplate">{xxxxxxxx-8F46-4948-AE74-DA5B6B5AFA86}</template>

  <template desc="mysiteLayout">{xxxxxx-64EE-4919-9D41-02FD40FD1466}</template>

  <item desc="mySiteHome">{xxxxxx-DEA5-42EA-9C1C-8A5DF7E70EF9}</item>
  <children desc="mySiteMainIems">{xxxxxxxx-DEA5-42EA-9C1C-8A5DF7E70EF9}</children>
</configuration>

So that all the relevant items that uses layouts, templates defined above are prefetched. Also the home and its children as well.

Is this a good approach, has anyone done this before and faced any issues /worked well?

Answer 1

The Second request being served well is for the reason it is returned from Sitecore caches - Item Cache or even HTML Cache, if that is configured for the rendering. Adding to Prefetch Cache might help, and you can check whether the required item is returned from cache or not, using Sitecore Cache Admin marketplace module

But, If your first request is taking long time to load the page, I would suggest you to check in code - lets say a Custom pipeline or processor - which is called on every request. Or say, a rendering which is added in the main Default Layout of your website. If you are using something like say ShareThis component, its good to add it as ASYNC on page, and it doesn't add up to the page load.

PS: A Strong Advice: Please do not hide code issues using cache, you might be able to shoo it away for now, but it will reappear sometime in future and with a problem bigger in size.

Answer 2

I have done it before and its good to cache frequently used items. One thing to note is application start time increases with size of prefetch catch i.e when you reset app pool it might take more time depending on size of cache.