mirror of
https://github.com/openshift/openshift-docs.git
synced 2026-02-05 12:46:18 +01:00
50 lines
2.0 KiB
Plaintext
50 lines
2.0 KiB
Plaintext
// Module included in the following assemblies:
|
|
// * hosted-control-planes/hcp-prepare/hcp-sizing-guidance.adoc
|
|
|
|
:_mod-docs-content-type: CONCEPT
|
|
[id="hcp-load-based-limit_{context}"]
|
|
= Load-based limit
|
|
|
|
The maximum number of {hcp} that the cluster can host is calculated based on the hosted control plane pods CPU and memory utilizations when some workload is put on the hosted control plane Kubernetes API server.
|
|
|
|
The following method is used to measure the hosted control plane resource utilizations as the workload increases:
|
|
|
|
* A hosted cluster with 9 workers that use 8 vCPU and 32 GiB each, while using the KubeVirt platform
|
|
* The workload test profile that is configured to focus on API control-plane stress, based on the following definition:
|
|
|
|
+
|
|
** Created objects for each namespace, scaling up to 100 namespaces total
|
|
+
|
|
** Additional API stress with continuous object deletion and creation
|
|
+
|
|
** Workload queries-per-second (QPS) and Burst settings set high to remove any client-side throttling
|
|
|
|
As the load increases by 1000 QPS, the hosted control plane resource utilization increases by 9 vCPUs and 2.5 GB memory.
|
|
|
|
For general sizing purposes, consider the 1000 QPS API rate that is a _medium_ hosted cluster load, and a 2000 QPS API that is a _heavy_ hosted cluster load.
|
|
|
|
[NOTE]
|
|
====
|
|
This test provides an estimation factor to increase the compute resource utilization based on the expected API load. Exact utilization rates can vary based on the type and pace of the cluster workload.
|
|
====
|
|
|
|
The following example shows hosted control plane resource scaling for the workload and API rate definitions:
|
|
|
|
.API rate table
|
|
|===
|
|
| QPS (API rate) | vCPU usage | Memory usage (GiB)
|
|
|
|
| Low load (Less than 50 QPS)
|
|
| 2.9
|
|
| 11.1
|
|
|
|
| Medium load (1000 QPS)
|
|
| 11.9
|
|
| 13.6
|
|
|
|
| High load (2000 QPS)
|
|
| 20.9
|
|
| 16.1
|
|
|===
|
|
|
|
The hosted control plane sizing is about control-plane load and workloads that cause heavy API activity, etcd activity, or both. Hosted pod workloads that focus on data-plane loads, such as running a database, might not result in high API rates. |