etcd pressure that limits cluster scale
Scaling Che to thousands of concurrent workspaces strains etcd, the primary datastore for Kubernetes cluster state. Three categories of objects contribute most to etcd growth: CA certificate bundles, DevWorkspace custom resources, and Copied CSVs. The procedures that follow address each one.
The primary datastore of Kubernetes cluster configuration and state is etcd. It holds information about nodes, pods, services, and custom resources.
As a distributed key-value store, etcd does not scale well past a certain threshold. As the size of etcd grows, so does the load on the cluster, risking its stability.
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The default etcd size is 2 GB, and the recommended maximum is 8 GB. Exceeding the maximum limit can make the Kubernetes cluster unstable and unresponsive. Even though the data stored in a |
The size of the objects stored in etcd is also a critical factor. Each object consumes space, and as the number of objects increases, the overall size of etcd grows. The larger the object, the more space it takes. For example, etcd can be overloaded with only a few thousand large Kubernetes objects.