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    Traffic Shaping ovpnc interface results in extreme CPU usage

    Scheduled Pinned Locked Moved Traffic Shaping
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    • N Offline
      namezero111111
      last edited by

      Dear folks,

      since upgrading one system for testing from 2.1 to 2.3.5, there have been extreme issues due to CPU usage.

      The system is used as a VPN gateway at a remote side and uses OpenVPN in Client mode as well as a CBQ shaper on the openvpn interface.

      However, after a few minutes (or heavy activity) the openvpn process pegs the CPU at 100% (mostly kernel time), and it stays that way even if the traffic stops.
      The high CPU causes timeouts and makes realtime apps (VoiP / RDP) unusable.
      Also, SSH connections to PFSense may break off as well as the WebGUI becomes sluggish/unresposive.

      As soon as the traffic shaper is disabled, the CPU usage drops to a few percent and the issue is gone (except no shaping, of course).

      There have been a few  reports about this, but no solution of using openvpn together with the shaper on 2.3.x:

      https://forum.pfsense.org/index.php?topic=134769.0

      https://forum.pfsense.org/index.php?topic=83861.15

      The altq config looks as follows:

      
       altq on ovpnc1 cbq qlimit 600  bandwidth 7168Kb queue {  qACK,  qDefault,  qDFSR,  qHigh,  qVeryHigh  }
      queue qACK on ovpnc1 bandwidth 15% priority 6 cbq (  red  , rio  , ecn ,  borrow  )
      queue qDefault on ovpnc1 bandwidth 20% priority 3 cbq (  red  , rio  , ecn  , default ,  borrow  )
      queue qDFSR on ovpnc1 bandwidth 20% priority 3 qlimit 550 cbq (  red  , rio  , ecn ,  borrow  )
      queue qHigh on ovpnc1 bandwidth 20% priority 4 cbq (  red  , rio  , ecn ,  borrow  )
      queue qVeryHigh on ovpnc1 bandwidth 20% priority 5 cbq (  red  , rio  , ecn ,  borrow  )
      
      

      Are there any insights into where to start debugging?
      We'd really like to upgrade from the older 2.1 versions.

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