DFS cluster split tables #

By default, the MySQLi DFS cluster will use distinct tables to store storage and cache files.

This makes maintenance and deployment much easier, by allowing to TRUNCATE the cache table and instantly remove all caches. There is also a performances benefit since less contention will happen on each table.

In a multi-site environment, it will also allow you to use different cache tables for different sites by setting a different cache table for each site.

Settings #

The feature is enabled by default.

CLUSTER_METADATA_TABLE_CACHE constant in config.[cluster.]php #

Default: "ezdfsfile_cache"

Defines the name of the table where cache files metadata is stored. Set it to an existing table to use this table for cache storage.

eZDFSClusteringSettings.MetaDataTableNameCache in file.ini #

Default: "ezdfsfile_cache"

Defines the name of the table where cache files metadata is stored. Set it to an existing table to use this table for cache storage.

Note: CLUSTER_METADATA_TABLE_CACHE is recommended over the INI setting, since it will affect both the FileHandler API, from within requests handled by index.php, and the cluster index used to deliver binary files over HTTP. We recommend that you use the constant and not the INI setting.

CLUSTER_METADATA_CACHE_PATH constant in config.[cluster.]php #

Default: "/cache/"

Path part for storage files, used to distinguish cache files from storage files. Must only be modified if you have changed FileSettings.StorageDir in site.ini.

CLUSTER_METADATA_STORAGE_PATH constant in config.[cluster.]php #

Default: "/storage/"

Path part for storage files, used to distinguish storage files from cache files. Must only be modified if you have changed FileSettings.StorageDir in site.ini.

Upgrading from Exponential < 5.2 #

If you migrate from an earlier version, it is recommended that you remove cache entries from the storage table.

To do so, the safest way is to:

• unclusterize data (bin/php/clusterize.php -u)
• run TRUNCATE TABLE ezdfsfile
• clusterize data again (bin/php/clusterize.php)

Backwards compatibility #

This change doesn't introduce any serious BC break. If you don't run the upgrade operation described above, the only consequence is that the unused cache entries in ezdfsfile will remain there.

You can also disable the feature completely by setting CLUSTER_METADATA_TABLE_CACHE to ezdfsfile in config.cluster.php.