APIGW 9.3 + When using APM, gateway java CPU usage becomes high load

Document ID : KB000120649
Last Modified Date : 09/11/2018
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Question:
High load of CUP will occur under the following circumstances.

CA API Gateway 9.3 CR3 
CA-Precision-API-Monitoring-3.3.179 

If the request continues to be sent its CPU load factor exceeds 100%. 
After that, even if the transmission of the request stops, the usage rate of the CPU does not decrease. 
This problem only occurs if Precision - API - Monitoring is installed. 

Reproduction procedure: 
set io.httpCoreConcurrency=20000 

run the following command 

while true do curl -s -o /dev/null http://done 

After a while the CPU utilization of the gateway java process exceeds 100% 
Then stop the above command. 
But, CPU usage will not decrease. 
Environment:
CA API Gateway 9.3 CR3 
CA-Precision-API-Monitoring-3.3.179 
Answer:

This is due to insufficient resources.
[io.httpCoreConcurrency = 20000]: It's is too much.

As a guideline, the following values are recommended.

Memory 8 GB:
io.httpCoreConcurrency = 500
io.httpMaxConcurrency = 750

Memory 32 GB:
io.httpCoreConcurrency = 2000
io.httpMaxConcurrency = 3000

Setting appropriate values is important.