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Configuration / Advanced Configuration / Sessions

By default, Bolt's sessions are managed behind the scenes for you by a configurable abstraction layer.

Configuration options are selected based on an order of precedence from varying locations, and merges options together.

Precedence is as follows:

  • Options from $app['session.options']
  • Options from php.ini, if enabled with $app['session.options.import_from_ini'] (enabled by default)
  • Fallback default options hard-coded in Bolt's SessionServiceProvider

These defaults are limited to those that are useful, and secure.

Note: Under most circumstances you should not need to adjust these settings.

Setting options

Changing session settings for a Bolt site can be done either by editing the site's config.yml file, or via dependency injection.

in your config.yml, settings are done adding the required parameter key and value, to the sessions key, i.e.:

    key: value

Setting via dependency injection is done by calling $app->share($app->extend()) on the 'session.options' container value, i.e.:

$app['session.options'] = $app->share($app->extend(
    function ($options) {
        // Use the $options parameter as a key/value hash map.
        // $options['key'] = 'value';

        return $options;

Browser cookies

By default, Bolt will inherit the settings cookies_lifetime, cookies_domain, and enforce_ssl (for cookie_secure) should no override options be set, as per the order of precedence explained in the introduction.

However, there are several override settings available, should you need more fine-grained control.

Life time

Time in seconds, that a cookie will be valid for. Setting this value to 0 means "until the browser is closed".

Key Default
cookie_lifetime 1209600 Integer >= 0

In .php.ini this setting is session.cookie_lifetime.

Base URI path

Specifies URI path to set in the session cookie.

Key Default
cookie_path / URI string

In .php.ini this setting is session.cookie_path.

Override domain name

Specifies the domain to set in the session cookie. Default is null, meaning the host name of the server which generated the cookie.

Key Default
cookie_domain HTTP(S) request host name A fully qualified domain name

In .php.ini this setting is session.cookie_domain.

Enforce HTTPS requests

Setting this to true will enforce a HTTPS connection requirement to set, and use, the session cookie.

Key Default
cookie_secure false Boolean on/off toggle

In .php.ini this setting is session.cookie_secure.

Restricting request to the HTTP protocol

Marks the cookie as accessible only through the HTTP protocol, blocking access to requests by things such as JavaScript.

This setting can effectively help to reduce identity theft through XSS attacks, although browser support may vary.

Key Default
cookie_httponly true Boolean on/off toggle

Setting in your config.yml:

In .php.ini this setting is session.cookie_httponly.

Session ID generation

Session IDs are randomly generated to uniquely identify a user's session. Bolt internally handles this generation in a fashion close to how PHP 7.1+ now does to better ensure the uniqueness of the generated ID.

By default, both PHP & Bolt use an ID length of 32, which should provide only a small chance of collisions, or predictability, of the generated ID.

On hosts with a consistent amount of available CPU resources, and a focus on security, you should consider a number of 48 or greater. However, this will increase the server load, and amount of time taken to generate session IDs.

An example of generating 1,000 session IDs on PHP 7.0 and an Intel i5-5200:

ID length milliseconds
32 0.002059
48 0.002560
64 0.003031
128 0.003016
256 0.004132

Maximum value supported is 256.

Key Default
sid_length 32 Integer between 32 & 256

In PHP 7.1+ the .php.ini this setting is session.sid_length.

Session storage handler

Session storage handling, by default, is our filesystem layer. However, we also support Redis & Memcached for more advanced use-cases.

Key Default
save_handler filesystem filesystem, redis, memcached

Setting in your config.yml:

In .php.ini this setting is session.save_handler.

Note: Some web hosting providers may implement alternative session handling that is not compatible with Bolt's.
Should you encounter exceptions from SessionServiceProvider indicating problems with PHP's system save path, set save_handler: filesystem, and the save_path option shown below.

Using the Redis handler

When using Redis as the handler, the following options are also under the connections subkey, of the session options:

Key Default
host localhost Host name or I.P. address of Redis server
port 6379 TCP port of Redis server
timeout 0.0 A float value in seconds (0.0 meanings unlimited)
persistent null Boolean to toggle persistent connections
password null (optional) Authenticate the connection using a password. Warning: The password is sent in plain-text over the network.
prefix null (optional) Prefix string used on all keys
database null Integer of the database index to connect to

If the native \Redis library is available, it will be used as the handler for Redis, if not available, it will instead check for the PHP implementation of the native library, \Predis\Client and use that.

Using the Memcached handler

When using Memcached as the handler, the following options are also under the connections subkey, of the session options:

Key Default
host localhost String host name or I.P. address of Memcached server
port 11211 TCP port of Memcached server
weight 0 (optional) The weight of the server relative to the total weight of all the servers in the pool. This controls the probability of the server being selected for operations.
expiretime 86400 (optional) Life time in seconds of stored keys
prefix sf2s (optional) Prefix string used on all keys

Saved session file path

Session data is cached in between requests. Bolt puts these files in a hidden directory of the cache, and is not cleared by the normal cache clearing functionality in Bolt.

Instead, it uses garbage collection to manage deletion of expired sessions. See the section below on garbage collection for details on configuration.

Key Default
save_path cache://.sessions Path passed to the save_handler

Note: Manually deleting session data on a live server is never advised. Should this ever be required on a live server, ensure all users are logged off, and place the site into maintenance mode first.

In .php.ini this setting is session.save_path.

Using the Filesystem handler

When using the default filesystem handler, the save_path parameter needs to be in the form of {mount point}://{path}.

See the Overview of Bolt's Filesystem page for details on the mount points available in Bolt.

Warning: If you set this to a world-readable directory, such as /tmp, other users on the server may be able to hijack sessions, or extract potentially sensitive data.

Using the Redis handler

When using Redis as the handler, save_path should be defined in the format tcp://IPADDRESS:PORT, with a default of tcp://

Using the Memcached handler

When using Memcached as the handler, save_path should be defined in the format IPADDRESS:PORT, with a default of

Garbage collection

Session garbage collection is the removal of sessions older than the configured maximum life time.

The need to perform garbage collection is determined based on a random probability calculation during the initialisation of each session.

Maximum life time

The maximum life time setting specifies the number of seconds after which session data will be seen as 'garbage' and potentially cleaned up.

Key Default
gc_maxlifetime 1209600 Integer of seconds

In .php.ini this setting is session.gc_maxlifetime.

Probability & divisor

The setting gc_divisor coupled with gc_probability define the probability that the garbage collection (GC) process is performed.

In Bolt's session storage handler, the probability is calculated by generating a random number between 0 and gc_divisor. If the value of gc_probability is greater than the random number, garbage collection will be performed, and session files older than the maximum configured life time are removed.

Note: To disable garbage collection, set gc_probability to -1.

Key Default
gc_probability 1 Integer
gc_divisor 1000 Integer

In .php.ini these settings are:

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