[j-nsp] j-series high cpu after upgrade

[L Kennedy]

Hi,

I upgraded our J2320 from 9.5 to 10.2 this week - the box is now crawling
with CPU consistently 90%.  As far as I can see we're still well within the
spec of the box though - aggregate traffic is < 100Mb/s; no. of flow
sessions is between 10k-20k.  It is not doing anything overly-complicated -
firewalling between 5 zones, a handful of bgp sessions exchanging only a
small number of routes.  "Top" shows that it is flowd that is consuming the
CPU but that doesn't really tell me anything useful:

> show chassis routing-engine
Routing Engine status:
    Temperature                 35 degrees C / 95 degrees F
    CPU temperature             44 degrees C / 111 degrees F
    Total memory               512 MB Max   451 MB used ( 88 percent)
      Control plane memory     298 MB Max   271 MB used ( 91 percent)
      Data plane memory        214 MB Max   180 MB used ( 84 percent)
    CPU utilization:
      User                       9 percent
      Real-time threads         91 percent
      Kernel                     0 percent
      Idle                       0 percent
    Model                          RE-J2320-2000
    Serial ID                      VH6168
    Start time                     2011-03-08 22:56:09 GMT
    Uptime                         14 hours, 40 minutes, 31 seconds
    Last reboot reason             0x2:watchdog
    Load averages:                 1 minute   5 minute  15 minute
                                       1.69       1.60       1.48

> show chassis forwarding
FWDD status:
  State                                 Online
  Microkernel CPU utilization        11 percent
  Real-time threads CPU utilization  87 percent
  Heap utilization                   84 percent
  Buffer utilization                  0 percent
  Uptime:                               3 hours, 25 minutes, 2 seconds

Anyone any thoughts before I roll back?

regards
Liam.