Advanced Connection

AdvancedConnection is a rails (~> 4.1) plugin that provides advanced management features for Rails' ActiveRecord connection pool. Features include:

Idle Connection Manager
Connection-less Code Blocks
Statement Pooling (EXPERIMENTAL)

Version

0.5.6

Installation

You need Gulp installed globally:

$ gem install advanced_connection

or in your Gemfile, add:

gem 'advanced_connection', '~> 0.5.6'

Then generate your AdvancedConnection configuration by executing:

bundle exec rails generate advanced_connection:install

Usage and Configuration

Idle Connection Manager

Enabling this will enable idle connection management. This allows you to specify settings to enable automatic warmup of connections on rails startup, min/max idle connections and idle connection culling.

  enable_idle_connection_manager = true | false

Pool queue type determines both how free connections will be checkout out of the pool, as well as how idle connections will be culled. The options are:

:fifo: All connections will have an equal opportunity to be used and culled (default)
:lifo, :stack: More frequently used connections will be reused, leaving less frequently used connections to be culled
:prefer_older: Longer lived connections will tend to stick around longer, with younger connections being culled
:prefer_younger: Younger lived connections will tend to stick around longer, with older connections being culled

  connection_pool_queue_type = :fifo | :lifo | :stack | :prefer_older | :prefer_younger

How many connections to prestart on initial startup of rails. This can help to reduce the time it takes a restarted production node to start responding again.

  warmup_connections = integer | false

Minimum number of connection to keep idle. If, during the idle check, you have fewer than this many connections idle, then a number of new connections will be created up to this this number.

  min_idle_connections = integer

Maximum number of connections that can remain idle without being culled. If you have more idle conections than this, only the difference between the total idle and this maximum will be culled.

  max_idle_connections = integer | Float::INFINITY

How long (in seconds) a connection can remain idle before being culled

  max_idle_time = integer

How many seconds between idle checks (defaults to max_idle_time)

  idle_check_interval = integer

Connection-less Code Blocks

Enabling this will add a new method to ActiveRecord::Base that allows you to mark a block of code as not requiring a connection. This can be useful in reducing pressure on the pool, especially when you have sections of code that make potentially long-lived external requests. E.g.,

 require 'open-uri'
 results = ActiveRecord::Base.without_connection do
   open('http://some-slow-site.com/api/')
 end

During the call to the remote site, the db connection is checked in and subsequently checked back out once the block finishes. To enable this feature, uncomment the following:

  enable_without_connection = true | false

WARNING: this feature cannot be enabled with Statement Pooling.

Additionally, you can hook into the checkin / checkout lifecycle by way of callbacks. This can be extremely useful when employing something like Apartment to manage switching between tenants.

without_connection_callbacks = {
  # runs right before the connection is checked back into the pool
  before:  ->() { },
  around:  ->(&block) {
    tenant = Apartment::Tenant.current
    block.call
    Apartment::Tenant.switch(tenant)
  },
  # runs right after the connection is checked back out of the pool
  after:  ->() { }
}

Advanced Connection

Version

Installation

Usage and Configuration

Idle Connection Manager

Connection-less Code Blocks

Statement Pooling

Todos

License