Fix in_monitor_agent's buffer_total_queued_size

[kimutansk]

Abstract

Now, in_monitor_agent's buffer_total_queued_size does't count queued chunk's sizes.
So fix for counting them.

Problem

• Version: Fluent1.1.3

• Buffer Settings

<buffer topic,tag>
  @type                       file
  path                        "/var/log/td-agent/buffer/#{ENV['PROCESS_NAME']}.forward_to_kafka.*.log"
  queued_chunks_limit_size    10000
  chunk_limit_size            32m
  total_limit_size            2400m
  flush_mode                  interval
  flush_interval              1.0
  flush_thread_burst_interval 0.1
  flush_thread_count          5
  retry_forever               true
  retry_max_interval          30s
  overflow_action             drop_oldest_chunk
</buffer>

• When that buffer plugin occured dropping oldest chunk to make space after buffer overflow, in_monitor agent returned below results.

plugin_category:output	type:kafka2	output_plugin:true	buffer_queue_length:10002	buffer_total_queued_size:39154788	retry_count:395

Queued total buffer size was about 2400mb, but in_monitor_agent's output was under 40mb, they were significantly different.

Reason

in_monitor_agent counts only stage_size, does't count queue_size.

https://github.com/fluent/fluentd/blob/v1.1.3/lib/fluent/plugin/in_monitor_agent.rb#L282

Fix detail

Fix in_monitor_agent's buffer_total_queued_size for counting queued chunk's sizes.

Fixed environment, in_monitor_agent's output was below, about 2400mb.

plugin_category:output	type:kafka2	output_plugin:true	buffer_queue_length:10002	buffer_total_queued_size:2513712017	retry_count:12

[repeatedly]

Could you update test?

[kimutansk]

Sorry, I missed.
Fixed in_monitor_agent's test.

[repeatedly]

Thanks!