Class: Gizzard::FinishMigrateCommand

Inherits:

Command

• Object
• Command
• Gizzard::FinishMigrateCommand

Defined in:

lib/gizzard/commands.rb

Instance Attribute Summary

Attributes inherited from Command

#argv, #buffer, #command_options, #global_options, #job_injector, #manager

Instance Method Summary

• #run ⇒ Object

Methods inherited from Command

classify, #confirm!, #get_base_name, #help!, #initialize, make_job_injector, make_manager, #output, #require_tables, #require_template_options, run

Constructor Details

This class inherits a constructor from Gizzard::Command

Instance Method Details

#run ⇒ Object

# File 'lib/gizzard/commands.rb', line 680

def run
  from_shard_id_string, to_shard_id_string = @argv
  help!("Requires source & destination shard id") unless from_shard_id_string && to_shard_id_string
  from_shard_id = ShardId.parse(from_shard_id_string)
  to_shard_id = ShardId.parse(to_shard_id_string)

  write_only_shard_id = ShardId.new("localhost", "#{to_shard_id.table_prefix}_migrate_write_only")
  replica_shard_id = ShardId.new("localhost", "#{to_shard_id.table_prefix}_migrate_replica")

  # careful. need to validate some basic assumptions.
  unless global_options.force
    if manager.list_upward_links(from_shard_id).map { |link| link.up_id }.to_a != [ replica_shard_id ]
      STDERR.puts "Uplink from #{from_shard_id} is not a migration replica."
      exit 1
    end
    if manager.list_upward_links(to_shard_id).map { |link| link.up_id }.to_a != [ write_only_shard_id ]
      STDERR.puts "Uplink from #{to_shard_id} is not a write-only barrier."
      exit 1
    end
    if manager.list_upward_links(write_only_shard_id).map { |link| link.up_id }.to_a != [ replica_shard_id ]
      STDERR.puts "Uplink from write-only barrier is not a migration replica."
      exit 1
    end
  end

  manager.remove_link(write_only_shard_id, to_shard_id)
  manager.list_upward_links(replica_shard_id).each do |link|
    manager.remove_link(link.up_id, link.down_id)
    manager.add_link(link.up_id, to_shard_id, link.weight)
  end
  manager.remove_link(replica_shard_id, from_shard_id)
  manager.remove_link(replica_shard_id, write_only_shard_id)
  manager.replace_forwarding(replica_shard_id, to_shard_id)
  manager.delete_shard(replica_shard_id)
  manager.delete_shard(write_only_shard_id)
end