<div dir="ltr">Hello there,<div>   </div><div>     As a performance optimization on our rabbit mq cluster (of 2 nodes), I removed following from a high volume non-durable queue</div><div><ol><li>AMQP_MANDATORY flag during publish and </li>

<li>AMQP_AUTOACK during consume. </li></ol> As a result the number of messages on that queue went down from 150 to 15 which is fantastic and expected. But this also increased overall cpu usage from 22% to 32% with an increased network traffic from 30k packets/sec to 40k packets/sec. The ingress & egress rate stayed the same before and after the change i.e. around 300 msgs/sec. </div>

<div><br></div><div>  So, my question is why would network traffic increase when I make all calls asynchronous when the ingress & egress rate is same ?</div><div><br></div><div>More info about the cluster:</div><div>
<div>
shri@mq1:~$ sudo rabbitmqctl status</div><div>Status of node rabbit@mq1 ...</div><div>[{pid,11689},</div><div> {running_applications,</div><div>     [{rabbitmq_management,"RabbitMQ Management Console","3.0.2"},</div>

<div>      {rabbitmq_management_agent,"RabbitMQ Management Agent","3.0.2"},</div><div>      {rabbit,"RabbitMQ","3.0.2"},</div><div>      {os_mon,"CPO  CXC 138 46","2.2.4"},</div>

<div>      {rabbitmq_mochiweb,"RabbitMQ Mochiweb Embedding","3.0.2"},</div><div>      {webmachine,"webmachine","1.9.1-rmq3.0.2-git52e62bc"},</div><div>      {mochiweb,"MochiMedia Web Server","2.3.1-rmq3.0.2-gitd541e9a"},</div>

<div>      {mnesia,"MNESIA  CXC 138 12","4.4.12"},</div><div>      {amqp_client,"RabbitMQ AMQP Client","3.0.2"},</div><div>      {xmerl,"XML parser","1.2.3"},</div>

<div>      {inets,"INETS  CXC 138 49","5.2"},</div><div>      {sasl,"SASL  CXC 138 11","2.1.8"},</div><div>      {stdlib,"ERTS  CXC 138 10","1.16.4"},</div><div>

      {kernel,"ERTS  CXC 138 10","2.13.4"}]},</div><div> {os,{unix,linux}},</div><div> {erlang_version,</div><div>     "Erlang R13B03 (erts-5.7.4) [source] [64-bit] [smp:12:12] [rq:12] [async-threads:30] [hipe] [kernel-poll:true]\n"},</div>

<div> {memory,</div><div>     [{total,469535752},</div><div>      {connection_procs,17995944},</div><div>      {queue_procs,11675696},</div><div>      {plugins,230048},</div><div>      {other_proc,126014264},</div><div>      {mnesia,18446743803509563784},</div>

<div>      {mgmt_db,12530864},</div><div>      {msg_index,1934440},</div><div>      {other_ets,-18446743803280937440},</div><div>      {binary,5524296},</div><div>      {code,18395964},</div><div>      {atom,3440321},</div>

<div>      {other_system,43167571}]},</div><div> {vm_memory_high_watermark,0.4},</div><div> {vm_memory_limit,5047128883},</div><div> {disk_free_limit,1000000000},</div><div> {disk_free,482189381632},</div><div> {file_descriptors,</div>

<div>     [{total_limit,65436},</div><div>      {total_used,309},</div><div>      {sockets_limit,58890},</div><div>      {sockets_used,298}]},</div><div> {processes,[{limit,1048576},{used,2992}]},</div><div> {run_queue,7},</div>

<div> {uptime,23771203}]</div><div>...done.</div></div><div><br></div><div><br></div><div>Thank you,</div><div>Shri</div></div>