I would advise opening a support case so we can troubleshoot what is hitting the CPU. I would not worry about appl in show cpu task. The generic fastiron process correlates with appl and generally shows as almost all of the usage there.
Ben Beck, RCNA, RCNI, Principal Technical Support Engineer support.ruckuswireless.com/contact-us
We are experiencing a High CPU during the day on ICX 7250 running Switching (Layer 2 traffic) and we used to have a high CPU on ICX 7550 Router due to Layer 4 and 5 packets. The reason why I mentioned both models is that both were connected to VSmart Zone and both were dropping CPU to 1% after I dsiconected them from SZ. So, we had the cas opened with Support and It took a lot itme to figure out why we had a hight CPU.