1 Reply Latest reply: Jun 30, 2015 2:12 AM by Amirul Islam RSS

    Flow control: What are your real world experiences?

    Dan King Wayfarer

      We have an internal discussion going that revolves around flow control.

      Arguments for enabling it:

      -Most every storage vendor recommends enabling it.

      -It can be more efficient at managing traffic than TCP dropping and re-sending packets.

       

      Arguments against enabling it:

      -TCP was designed to handle its own flows.

      -Pause frames from a host unable to handle traffic can negatively impact other hosts currently not having issues.

       

       

      Anyone have any real world experiences where flow control either improved or hindered performance?

      Any other insight?

        • Re: Flow control: What are your real world experiences?
          Amirul Islam Adventurer

          Hi Dan,

          I've seen issues in a SmartStack when flow control hasn't been enabled. During high performance load and a manual controller failover, we observed 2 things:

          1) the time for activity to resume after the failover took longer than with flow control enabled

          2) 'choppy' performance (peaks and troughs in monitor>performance charts for IOPS) on the Nimble rather than consistent performance