When your application has one instance, it’s generally safe to use the default session storage, which is the local file system. You can only see problems if your single instance crashes, the local file system goes away, and you lose your sessions. For many applications, this works just fine, but you need to consider how this affects your application.
If you have multiple application instances or you need a more robust solution for your application, use Redis or Memcached as a backup store for your session data. The buildpack supports both backups and when one is bound to your application, it detects it and configures PHP to use it for session storage.
By default, there is no configuration necessary. To create a Redis or Memcached service, ensure that the service name contains redis-sessions
or memcached-sessions
and then bind the service to the application.
Example:
$ cf create-service redis some-plan app-redis-sessions $ cf bind-service app app-redis-sessions $ cf restage app
If you want to use a specific service instance or change the search key, you can set either REDIS_SESSION_STORE_SERVICE_NAME
or MEMCACHED_SESSION_STORE_SERVICE_NAME
in .bp-config/options.json
to the new search key. The session configuration extension searches the bound services by name for the new session key.
When detected, the following changes are made:
redis
PHP extension is installed, which provides the session save handlersession.name
is set to PHPSESSIONID
which deactivates sticky sessionssession.save_handler
is configured to redis
session.save_path
is configured based on the bound credentials, for example tcp://host:port?auth=pass
memcached
PHP extension is installed, which provides the session save handlersession.name
is set to PHPSESSIONID
which deactivates sticky sessionssession.save_handler
is configured to memcached
session.save_path
is configured based on the bound credentials (i.e. PERSISTENT=app_sessions host:port
)memcached.sess_binary
is set to On
memcached.use_sasl
is set to On
, which enables authenticationmemcached.sess_sasl_username
and memcached.sess_sasl_password
are set with the service credentials