API GW Openshift cluster memory problem

Products

• CA API Gateway
• API SECURITY
• CA API Gateway Precision API Monitoring Module for API Gateway (Layer 7)
• CA API Gateway Enterprise Service Manager (Layer 7)
• STARTER PACK-7
• CA Microgateway

Issue/Introduction

We have problem with our openshift installation. We have 2 clusters each has a node (pod) running with GW 9.4 version. Last week, we have updated both clusters' memory from 4gi to 8gi. Since then 1st cluster does not have any problems however 2nd cluster consistently getting java.lang.OutOfMemoryError exception after running the pod for around 10 min. 

2020-04-06T08:54:55.666+0000 SEVERE  148    org.apache.tomcat.util.net.JIoEndpoint: Error allocating socket processor
java.lang.OutOfMemoryError: unable to create new native thread
 at java.lang.Thread.start0(Native Method)
 at java.lang.Thread.start(Thread.java:717)

Environment

Release : 9.4

Component : API GATEWAY

Cause

We also set at the same time :
io.httpCoreConcurrency=4500 and io.httpMaxConcurrency=6000

Resolution

Increasing the pod memory settings to  8gb is not enough for running io.httpCoreConcurrency=4500 and io.httpMaxConcurrency=6000 
 
containers:
    - resources:
        limits:
          cpu: 1500m
          memory: 8Gi
        requests:
          cpu: 800m
          memory: 4Gi
      readinessProbe:


Increase the pod memory allocation to 16gb or reduce io.httpCoreConcurrency and  io.httpMaxConcurrency