I've currently written an environment.rb that reads the /etc/aws/hosts directory and populates the memcache server array with the then current members of the memcached role.
What is the least invasive way of repopulating the memcache object when that directory structure changes either due to scaling or failure without having to restart the rails stack? (We use apache2 with passenger and RubyE as our rails stack) There is also some fragility with this method because only ip addresses are used to identify the instances, and if those instances change thier ip's due to dhcp, then #1 they become unavailable to the memcache object, and #2 even if we could repopulate the memcache object with the now current IP's, the hashing algorithm would change and they keys would most likely result in misses anyway. In my testing if memcache goes down, this method also results in a server 500 error, until the memcache process is restarted and becomes available. That's not good, we need a way to continue running the app, albiet with reduced performance while memcache is MIA. We need a more fault tolerant solution and I'm assuming we are going to have to have the sessions ultimately be database backed. Are there any solutions that folks are using in this environment that combine a scaling memcache role and db backed rails sessions? --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "scalr-discuss" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/scalr-discuss?hl=en -~----------~----~----~----~------~----~------~--~---
