Introduction

Tech Note

Current implementation uses a caching library called Stash, via Stash-bundle. If this changes, then the configuration format will most likely change as well. Stash supports the following cache handlers: FileSystem, Memcache, APC, Sqlite, XCache and BlackHole.

Cache service

The cache system is exposed as a "cache" service, and can be reused by any other service as described on the Persistence cache page.

Configuration

During Setup wizard and manually using ezpublish:configure console command a default configuration is generated currently using FileSystem, using %kernel.cache_dir%/stash to store cache files.

The configuration is placed in ezpublish/config/ezpublish.yml, and looks like:

stash:
    caches:
        default:
            handlers:
                - FileSystem
            inMemory: false
            registerDoctrineAdapter: false

The default settings used during setup wizard as found in ezpublish/config/ezpublish_setup.yml:

stash:
    caches:
        default:
            handlers:
                - BlackHole
            inMemory: true
            registerDoctrineAdapter: false

This setting works across all installs and just caches objects within the same request thanks to the inMemory: true setting.

If you want to change to another handler, see in Stash handlers configuration below for what kind of settings you have available.

Multi repository setup

New in 5.2 is the possibility to select a specific Stash cache pool on a siteaccess or sitegroup level, the following example shows use in a sitegroup:

        ezdemo_group:
            cache_pool_name: "default"
            database:
                ...

The "default" here refers to the name of the cache pool as specified in the stash configuration block shown above, if your install has several repositories (databases), then make sure every group of sites using different repositories also uses a different cache pool to avoid unwanted effects.
NB: We plan to make this more native in the future, so this setting will someday not be needed.

Stash handlers configuration

General settings

To check which cache settings are available for your installation, run the following command in your terminal :

php ezpublish/console config:dump-reference stash

FileSystem

This cache handler is using local filesystem, by default the Symfony cache folder, as this is per server, it does not support multi server (cluster) setups!

Available settings

path

dirSplit

filePermissions

dirPermissions

memKeyLimit

keyHashFunction

stash:
    caches:
        default:
            handlers:
                - FileSystem
            inMemory: true
            registerDoctrineAdapter: false
            FileSystem:
                keyHashFunction: 'crc32'

APC

This cache handler is using shard memory using APC's user cache feature, as this is per server, it does not support multi server (cluster) setups, unless you use PHP-FPM on a dedicated server (this way, user cache can be shared among all the workers in one pool).

Please also note that the default value for apc.shm_size is 128MB. However, 256MB is recommended for APC to work properly. For more details please refer to the APC configuration manual.

Available settings

Memcache

This cache handler is using Memcached, a distributed caching solution, this is the only supported cache solution for multi server (cluster) setups!

For in-depth information on the settings, see: http://php.net/Memcached

Example with Memcache

stash:
    caches:
        default:
            handlers: [ Memcache ]
            inMemory: true
            registerDoctrineAdapter: false
            Memcache:
                prefix_key: ezdemo_
                retry_timeout: 1
                servers:
                    -
                        server: 127.0.0.1
                        port: 11211