What is 'Slow Timer Recovery by rebooting itself' in AP System Profile ?
Sometimes all of sudden SSIDs will not being broadcasted in 2.4GHz radio on AP's. Clock Sync issue between AP and the controller could be one of the reason for this issue.
In below example we can see that there is a difference of more than 3min between the controller and AP clock. Due to this we might face the problem with the AP.
As a short term solution, in the latest image version(>220.127.116.11 or 18.104.22.168 and above) we do have an new option called 'Slow Timer Recovery by rebooting itself'. When this knob is enabled, AP will automatically reboot when the failure is detected.
(Aruba7030) #show ap system-profile default | include Timer
Slow Timer Recovery by rebooting itself Disabled
(Aruba7030) #configure terminal ap system-profile default
(Aruba7030) (AP system profile "default") #slow_timer_recovery
Controller Clock: ================ \par (NV-AK130-AC01) #show clock \par \par Fri Nov 18 11:12:28 CET 2016 Affected AP clock: ================= ~ # date Fri Nov 18 11:08:50 CET 2016 ~ # cat /proc/interrupts | grep timer 7: 4139525525 MIPS timer