title: Magento "Front controller reached 100 router match iterations" error
body: <p>My site is going down once or twice a day when it starts throwing the exception "Front controller reached 100 router match iterations". Once this happens access to the admin and frontend is gone. I am just left with an error page.</p>
  
  <p>This started after upgrading from Magento 1.5.0.1 to 1.5.1.0. If I manually clear the var/cache/ directory I am up and running again.</p>
  
  <p>I have googled the heck out of this one. In the limited search results I have found nothing has helped me with resolving this.</p>
  
  <p>Any insight into why this may be happening and how it could be resolved would be appreciated.</p>
  
  <p>--update-----------------------</p>
  
  <p>Using the debugging code provided in the helpful answer from, Andrey Tserkus, I was able to determine that the error is caused by some of my routers disappearing. </p>
  
  <p>The normal routers output by the debug code are: 
  Total 7: admin, standard, cms, amshopby, fishpig_wordpress, seosuite, default</p>
  
  <p>When the error occurs they have changed to:
  Total 3: admin, standard, default</p>
  
  <p>When this happens it seems the missing routes causes the code to iterate to 100 for every page request. I will investigate this condition further.</p>