Let's say you've got a site that you're taking into a phase that will have lots of traffic.
Let's say you've decided to centralize on a single database machine.
Let's say you have many load balanced web servers on the front end.
Let's say you're considering putting a memcache on each of the front ends, and taking advantage of the fact that it can be configured to write to the DB, and read from the memcache.
What about the issue that as soon as you have a write to the DB, most of your memcaches are now out of date?
Would it be advisable and straight forward to send all writes not only to the DB but also to all the memcache instances?
Would it make more sense to start splitting off your tables onto different MySQL servers? What are you favorite tables to split off?
Anyone with experience on this care to share?
Comments
Wrong use of memcache
the great advantage of memcache is that you access a central server from all of your web heads so that the cache isn't redundant. It is a network based cache so in the settings.php file you tell Drupal about the hostname/IP address plus port of the memcache server and it gets accessed over the network.
You will want to start one memcache server for every cache_* table you have. This prevents the clearing of one cache from spilling over into other caches and wastefully losing data. This is all described pretty well here: http://www.lullabot.com/articles/how_install_memcache_debian_etch
Thanks!
Thank you. :-)
http://www.sticksallison.com
http://www.sticksallison.com