Sidekiq worker for Elasticsearch with connection pool

indexer.rb

module Search
  class Indexer
    include Sidekiq::Worker
    sidekiq_options queue: :low, retry: false, backtrace: true

    LOGGER = Sidekiq.logger.level == Logger::DEBUG ? Sidekiq.logger : nil

    SEARCH_POOL = ConnectionPool.new(size: SEARCH_UPDATE_POOL, timeout: 5) do
      Elasticsearch::Client.new host: ELASTICSEARCH_URL, logger: LOGGER
    end

    def perform(operation, klass, record_id, options = {})
      LOGGER.debug [operation, "#{klass}##{record_id} #{options.inspect}"] if LOGGER

      case operation.to_s
      when /index|update/
        SEARCH_POOL.with do |client|
          record = klass.constantize.find(record_id)
          record.__elasticsearch__.client = client
          record.__elasticsearch__.__send__ "#{operation}_document"
        end
      when /delete/
        SEARCH_POOL.with do |client|
          client.delete index: klass.constantize.index_name, type: klass.constantize.document_type, id: record_id
        end
      else
        fail ArgumentError, "Unknown operation '#{operation}'"
      end
    end
  end
end