Module: DeadBro::Collectors::Database

Defined in:
lib/dead_bro/collectors/database.rb

Overview

Database collector provides lightweight, best-effort information about the current ActiveRecord connection pool and a simple ping latency measurement.

Class Method Summary collapse

Class Method Details

.collect ⇒ Object 



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# File 'lib/dead_bro/collectors/database.rb', line 12

def collect
  return {disabled: true} unless db_enabled?
  return {available: false} unless defined?(::ActiveRecord)

  base = ::ActiveRecord::Base
  return {available: false} unless base.respond_to?(:connection_pool) && base.connection_pool

  pool = safe_connection_pool(base)

  {
    available: true,
    pool: pool_stats(pool),
    ping_ms: ping_ms(base)
  }
rescue => e
  {
    error_class: e.class.name,
    error_message: e.message.to_s[0, 500]
  }
end

.current_time ⇒ Object 



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# File 'lib/dead_bro/collectors/database.rb', line 107

def current_time
  Process.clock_gettime(Process::CLOCK_MONOTONIC)
rescue
  Time.now.to_f
end

.db_enabled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dead_bro/collectors/database.rb', line 33

def db_enabled?
  DeadBro.configuration.respond_to?(:enable_db_stats) &&
    DeadBro.configuration.enable_db_stats
rescue
  false
end

.elapsed_ms(started) ⇒ Object 



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# File 'lib/dead_bro/collectors/database.rb', line 113

def elapsed_ms(started)
  ((current_time - started) * 1000.0).round(2)
rescue
  nil
end

.ping_ms(base) ⇒ Object 



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# File 'lib/dead_bro/collectors/database.rb', line 89

def ping_ms(base)
  started = current_time
  base.connection_pool.with_connection do |conn|
    sql = case conn.adapter_name.to_s.downcase
    when /mysql/
      "SELECT 1"
    when /sqlite/
      "SELECT 1"
    else
      "SELECT 1"
    end
    conn.select_value(sql)
  end
  elapsed_ms(started)
rescue
  nil
end

.pool_stats(pool) ⇒ Object 



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# File 'lib/dead_bro/collectors/database.rb', line 54

def pool_stats(pool)
  return {} unless pool

  {
    size: begin
      safe_integer(pool.size)
    rescue
      nil
    end,
    connections: begin
      safe_integer(pool.connections.size)
    rescue
      nil
    end,
    busy: begin
      safe_integer(pool.respond_to?(:busy) ? pool.busy : nil)
    rescue
      nil
    end,
    dead: begin
      safe_integer(pool.respond_to?(:dead) ? pool.dead : nil)
    rescue
      nil
    end,
    num_waiting: begin
      safe_integer(pool.respond_to?(:num_waiting) ? pool.num_waiting : nil)
    rescue
      nil
    end,
    automatic_reconnect: pool.respond_to?(:automatic_reconnect) ? !!pool.automatic_reconnect : nil
  }
rescue
  {}
end

.safe_connection_pool(base) ⇒ Object 



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# File 'lib/dead_bro/collectors/database.rb', line 40

def safe_connection_pool(base)
  if base.respond_to?(:connection_pool)
    base.connection_pool
  elsif base.respond_to?(:connection_handler)
    begin
      base.connection_handler.retrieve_connection_pool(base)
    rescue
      nil
    end
  end
rescue
  nil
end

.safe_integer(value) ⇒ Object 



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# File 'lib/dead_bro/collectors/database.rb', line 119

def safe_integer(value)
  Integer(value)
rescue
  nil
end