I found the issue. I have a folder "user" in which 300k+ json is available. On my website, stats are being counted by those json. That is why cpu is 100% with the single visitors only. I have removed that stats counting code, now website is fine. But the matter is in Filemanger, if I try to open that folder "user" then aapanel gives time out. I check via ssh, bt-panel is using 100% cpu. But same folder I open in cPanel server then no high load. Why only aapanel has this issue?