High CPU utilization spikes were being reported to be occurring at, or near the same time every day-- on two separate Linux Servers. The utilization spikes were lasting anywhere from 30 seconds to five minutes.
The problem seemed to be happening after the DCS agent was installed on the RHEL 8 server(s)
Release : 6.9.1
An examination of the sisamdaemon logs showed that, at the time the CPU spike occurred (on both servers) the anti-malware program (AMD) was scanning the Oracle database folders which each of the two servers had installed on them.
Both servers had details gathered from sisamdaemon log found in .\var\log\sdcsslog\amdlog\
computer-508 Feb. 11 23:41 (11:41pm) Process: sisamdaemon 25% CPU 1.14GB Memory
Anti-Malware scan (sisamdaemon) starts at 11:31:48pm and runs until 11:42:30pm
At 11:31pm it starts heavy scanning in SQL and Oracle folders. In fact the last folders being scanned when the process completed were Oracle. Oracle is the second item in the process tree at 1.98 CPU and 1,002MB of Memory
Modifying the exclusion policy for AMD and antivirus to exclude the folders containing the Oracle database files eliminated the problem. The CPU spike did not occur again.