Method: Fluent::Plugin::Output#write_guard

Defined in:

lib/fluent/plugin/output.rb

#write_guard(&block) ⇒ Object

# File 'lib/fluent/plugin/output.rb', line 975

def write_guard(&block)
  begin
    block.call
  rescue Fluent::Plugin::Buffer::BufferOverflowError
    log.warn "failed to write data into buffer by buffer overflow", action: @buffer_config.overflow_action
    case @buffer_config.overflow_action
    when :throw_exception
      raise
    when :block
      log.debug "buffer.write is now blocking"
      until @buffer.storable?
        if self.stopped?
          log.error "breaking block behavior to shutdown Fluentd"
          # to break infinite loop to exit Fluentd process
          raise
        end
        log.trace "sleeping until buffer can store more data"
        sleep 1
      end
      log.debug "retrying buffer.write after blocked operation"
      retry
    when :drop_oldest_chunk
      begin
        oldest = @buffer.dequeue_chunk
        if oldest
          log.warn "dropping oldest chunk to make space after buffer overflow", chunk_id: dump_unique_id_hex(oldest.unique_id)
          @buffer.purge_chunk(oldest.unique_id)
        else
          log.error "no queued chunks to be dropped for drop_oldest_chunk"
        end
      rescue
        # ignore any errors
      end
      raise unless @buffer.storable?
      retry
    else
      raise "BUG: unknown overflow_action '#{@buffer_config.overflow_action}'"
    end
  end
end