Seeing alerts against the monitors and not showing any issues when checking from alternate monitoring tools.
Per engineering, an issue on some stations, where the Linux kernel is using too much memory.
Because there was not enough free memory for user-space, the machines were swapping heavily and most checks were rejected due to load.
Release : 99.0
Component : CA APP SYNTHETIC MONITOR (WATCHMOUSE)
The fix is a reboot of the station.
The following stations were rebooted and are now accepting all the checks:
Melbourne, Peth, Sofia, Vancouver, Prague, Denmark, Athens, Milan, Tokyo, Vilnius, Kuala Lumpur, Kharkov, Ho Chi Minh City, Cape Town.