Wiremock 3.x has CPU Throttling issue while running performance testing in docker containers

Proposal

After upgrading wiremock 2.x to 3.x having CPU Throttling issue while running performance testing(locust in our case) in Docker containers. Attached the 2 version comparison details (JFR files omitted incase having sensitive data but details shared in wiremock slack community) Issue Details.zip

In our use case we have 4 WireMock container used as User Profile with 5ms delay

Each Container settings:

resources:
  requests:
    cpu: 250m
    memory: 1024Mi
  limits:
    cpu: 1000m
    memory: 1024Mi

Expected Behavior: While running the performance test against 4 wiremock containers with 80K request per min with total 1mil request in 15 min, expecting that there will be no CPU throttling or Memory issue.

Actual Behavior: When running the performance test against 4 wiremock container with 80K request per min, CPUT throttling starts after 3-4 min and it jumps almost 10-15 times of the CPU limits and causing containers to restart many times and crashing them.

Reproduction steps

Issue can be reproduced by running wiremock in Docker containers with using locust performance testing with 20-80K request / per min ramp up in 10min.

References

This issue discussed in wiremock slack community and here is the thread Slack Thread