How to tell doctrine to ignore Memcached if server is offline? - php

Question

I'm testing Memcached on my Symfony2 application
I set it to cache doctrine's queries, results and metadata:
orm:
entity_managers:
default:
metadata_cache_driver:
type: service
id: doctrine.cache.memcache2
query_cache_driver:
type: service
id: doctrine.cache.memcache2
result_cache_driver:
type: service
id: doctrine.cache.memcache2
services:
memcache:
class: Memcache
calls:
- [ addserver, [ 'localhost', 11211 ]]
doctrine.cache.memcache2:
class: Doctrine\Common\Cache\MemcacheCache
calls:
- [setMemcache, [#memcache]]
Until now, everything works fine.
I was wondering how does doctrine behaves if the Memcached server goes down. As far as I could see, the application breaks. In dev mode I get the following message:
Notice: MemcachePool::get(): Server localhost (tcp 11211, udp 0) failed with: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
(10060)
500 Internal Server Error - ContextErrorException
In production mode I'm also presented with an http 500.
Is there a way to tell doctrine to bypass/ignore the Memcached server and go directly to the database, instead of returning 500s?

Answer 1

You can use The Second Level Cache available in doctrine/orm 2.5
see:
http://doctrine-orm.readthedocs.org/projects/doctrine-orm/en/latest/reference/second-level-cache.html
The idea to keep you default options for orm and add a memcache as second level cache:
orm:
entity_managers:
default:
auto_mapping: true
second_level_cache:
region_cache_driver:
type: service
id: doctrine.cache.memcache2
enabled: true
regions:
region_name:
cache_driver:
type: service
id: doctrine.cache.memcache2
When turned on, entities will be first searched in cache and if they are not found, a database query will be fired and then the entity result will be stored in a cache provider.