Phoenix.SessionProcess.Config (phoenix_session_process v1.0.1)

Configuration management for Phoenix.SessionProcess.

This module provides access to all configurable aspects of the session process library. Configuration is done through application environment variables and can be set in your config/config.exs file.

Configuration Options

All configuration is done under the :phoenix_session_process application key:

config :phoenix_session_process,
  session_process: MyApp.SessionProcess,  # Default session module
  max_sessions: 10_000,                   # Maximum concurrent sessions
  session_ttl: 3_600_000,                # Session TTL in milliseconds (1 hour)
  rate_limit: 100,                       # Sessions per minute limit
  unmatched_action_handler: :log         # How to handle unmatched actions (:log, :warn, :silent, or custom function)

Options

`:session_process`

Type: module()
Default: Phoenix.SessionProcess.DefaultSessionProcess
Description: The default module to use when creating session processes without specifying a module

`:max_sessions`

Type: integer()
Default: 10_000
Description: Maximum number of concurrent sessions allowed. Helps prevent memory exhaustion.

`:session_ttl`

Type: integer()
Default: 3_600_000 (1 hour in milliseconds)
Description: Time-to-live for idle sessions. Sessions are automatically cleaned up after this period.

`:rate_limit`

Type: integer()
Default: 100
Description: Maximum number of new sessions that can be created per minute. Prevents abuse.

`:unmatched_action_handler`

Type: :log | :warn | :silent | (action, reducer_module, reducer_name -> any())
Default: :log
Description: How to handle actions that don't match any pattern in a reducer's handle_action/2:
- :log - Log debug message suggesting use of action prefix
- :warn - Log warning message (useful for debugging)
- :silent - No logging
- Custom function with arity 3: fun(action, reducer_module, reducer_name)

Runtime Configuration

Configuration can be provided in two ways:

1. Application Environment (config files)

# config/config.exs
config :phoenix_session_process,
  session_process: MyApp.SessionProcess,
  max_sessions: 10_000

2. Supervisor Start Options (runtime)

# lib/my_app/application.ex
def start(_type, _args) do
  children = [
    {Phoenix.SessionProcess, [
      session_process: MyApp.SessionProcess,
      max_sessions: 20_000,
      session_ttl: :timer.hours(2),
      rate_limit: 150
    ]}
  ]

  Supervisor.start_link(children, strategy: :one_for_one)
end

Priority: Runtime options (passed to supervisor) take precedence over application environment.

Environment-specific Configuration

Different environments can have different configurations:

# config/dev.exs
config :phoenix_session_process,
  session_ttl: :timer.hours(8)  # Longer TTL for development

# config/prod.exs
config :phoenix_session_process,
  max_sessions: 50_000,         # Higher limit for production
  session_ttl: :timer.minutes(30)  # Shorter TTL for production

Summary

Functions

max_sessions()

Returns the maximum number of allowed concurrent sessions.

rate_limit()

Returns the rate limit for session creation (sessions per minute).

session_process()

Returns the configured default session process module.

session_ttl()

Returns the session time-to-live (TTL) in milliseconds.

unmatched_action_handler()

Returns the handler for unmatched actions in reducers.

valid_session_id?(session_id)

Validates whether a session ID has the correct format.

Functions

max_sessions()

@spec max_sessions() :: integer()

Returns the maximum number of allowed concurrent sessions.

Examples

iex> max = Phoenix.SessionProcess.Config.max_sessions()
iex> is_integer(max)
true
iex> max > 0
true

Returns

integer() - Maximum concurrent sessions allowed (default: 10,000)

Configuration

Set in your config file:

config :phoenix_session_process,
  max_sessions: 50_000

rate_limit()

@spec rate_limit() :: integer()

Returns the rate limit for session creation (sessions per minute).

Examples

iex> limit = Phoenix.SessionProcess.Config.rate_limit()
iex> is_integer(limit)
true
iex> limit > 0
true

Returns

integer() - Maximum sessions that can be created per minute (default: 100)

Configuration

Set in your config file:

config :phoenix_session_process,
  rate_limit: 200  # Allow 200 sessions per minute

Note

This helps prevent session creation abuse and protects against DoS attacks.

session_process()

@spec session_process() :: module()

Returns the configured default session process module.

Examples

iex> module = Phoenix.SessionProcess.Config.session_process()
iex> is_atom(module)
true

Returns

module() - The configured session process module, or Phoenix.SessionProcess.DefaultSessionProcess if not configured

Configuration

Set in your config file:

config :phoenix_session_process,
  session_process: MyApp.CustomSessionProcess

session_ttl()

@spec session_ttl() :: integer()

Returns the session time-to-live (TTL) in milliseconds.

Examples

iex> ttl = Phoenix.SessionProcess.Config.session_ttl()
iex> is_integer(ttl)
true
iex> ttl > 0
true

Returns

integer() - Session TTL in milliseconds (default: 3,600,000 = 1 hour)

Configuration

Set in your config file:

config :phoenix_session_process,
  session_ttl: :timer.hours(2)  # 2 hours

Note

Sessions are automatically cleaned up after being idle for this duration.

unmatched_action_handler()

@spec unmatched_action_handler() :: :log | :warn | :silent | function()

Returns the handler for unmatched actions in reducers.

Examples

iex> Phoenix.SessionProcess.Config.unmatched_action_handler()
:log

Returns

:log - Log debug messages for unmatched actions (default)
:warn - Log warning messages for unmatched actions
:silent - No logging
function/3 - Custom handler function with signature: fun(action, reducer_module, reducer_name)

Configuration

Set in your config file:

config :phoenix_session_process,
  unmatched_action_handler: :warn

# Or with custom function:
config :phoenix_session_process,
  unmatched_action_handler: fn action, module, name ->
    MyApp.Metrics.track_unmatched_action(action, module, name)
  end

Note

This helps debug action routing issues. If you see many unmatched actions, consider using @action_prefix to limit which actions are routed to each reducer.

valid_session_id?(session_id)

@spec valid_session_id?(any()) :: boolean()

Validates whether a session ID has the correct format.

Examples

iex> Phoenix.SessionProcess.Config.valid_session_id?("valid_session_123")
true

iex> Phoenix.SessionProcess.Config.valid_session_id?("invalid@session")
false

iex> Phoenix.SessionProcess.Config.valid_session_id?("")
false

iex> Phoenix.SessionProcess.Config.valid_session_id?(nil)
false

Parameters

session_id - The session ID to validate

Returns

boolean() - true if the session ID is valid, false otherwise

Validation Rules

Must be a binary string
Length must be between 1 and 64 characters
Can only contain alphanumeric characters, underscores, and hyphens
This ensures URL-safety and prevents injection attacks