Community Cluster is a Kubernetes cluster running on Google Kubernetes Engine that is available free of charge for Open Source community. Paying customers can also use Community Cluster for personal private repositories.
Community Cluster is configured the same way as anyone can configure a personal GKE cluster as described here.
By default a container is given 2 CPUs and 4 Gb of memory but it can be configured in
container: image: openjdk:8-jdk cpu: 4 memory: 12 task: script: ...
Containers on Community Cluster can use maximum 8.0 CPUs and up to 24 Gb of memory. Custom GKE clusters don't have that limitation though.
Scheduling Times on Community Cluster
Since Community Cluster is shared, scheduling times for containers can vary from time to time. Also the smaller a container require resources faster it will be scheduled.