postgresql-ec2.rb

total_memory = node[:memory][:total]
memory_size = Chef::Search::Query.new.search(:ec2_enums, "id:memory_size").flatten.first

if ( total_memory.to_i <= memory_size['small'].to_i ) 
  set[:postgresql][:shmmax] = "33554432"
  set[:postgresql][:shmall] = "2097152"
  set[:postgresql][:shmmni] = "4096"
  set[:postgresql][:max_connections] = "25"
  set[:postgresql][:shared_buffers] = "35MB"
  set[:postgresql][:work_mem] = "2MB"
  set[:postgresql][:maintenance_work_mem] = "2MB"
  set[:postgresql][:archive_ip] = ""
  set[:postgresql][:effective_cache_size] = "512MB"
  set[:postgresql][:log_min_duration_statement] = "200"
  set[:postgresql][:commit_delay] = "100"
  set[:postgresql][:checkpoint_segments] = "512"
  set[:postgresql][:random_page_cost] = "3.0"
elsif ( total_memory.to_i <= memory_size['huge'].to_i )
  set[:postgresql][:shmmax] = "73408081920"
  set[:postgresql][:shmall] = "1147001280"
  set[:postgresql][:shmmni] = "16384"
  set[:postgresql][:max_connections] = "500"
  set[:postgresql][:shared_buffers] = "35GB"
  set[:postgresql][:work_mem] = "5GB"
  set[:postgresql][:maintenance_work_mem] = "13GB"
  set[:postgresql][:archive_ip] = ""
  set[:postgresql][:effective_cache_size] = "50GB"
  set[:postgresql][:log_min_duration_statement] = "200"
  set[:postgresql][:commit_delay] = "100"
  set[:postgresql][:checkpoint_segments] = "512"
  set[:postgresql][:random_page_cost] = "3.0"
end