Merge pull request #1731 from moio/discourage_third_party_sw

Discourage third party software on the upstream cluster
2026-09-25 12:38:05 +00:00 · 2025-07-07 08:32:21 -07:00
parent 9002cec58f c92719e715
commit f273d54164
22 changed files with 266 additions and 148 deletions
@@ -40,4 +40,3 @@ However, metrics-driven capacity planning analysis should be the ultimate guidan
 Using Rancher, you can monitor the state and processes of your cluster nodes, Kubernetes components, and software deployments through integration with Prometheus, a leading open-source monitoring solution, and Grafana, which lets you visualize the metrics from Prometheus.

 After you [enable monitoring](../../../integrations-in-rancher/monitoring-and-alerting/monitoring-and-alerting.md) in the cluster, you can set up alerts to let you know if your cluster is approaching its capacity. You can also use the Prometheus and Grafana monitoring framework to establish a baseline for key metrics as you scale.
-
@@ -10,7 +10,7 @@ This guide contains our recommendations for running the Rancher server, and is i

 ### Recommended Architecture and Infrastructure

-Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server on a high-availability Kubernetes cluster.
+Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server for a production installation.

 ### Deployment Strategies

@@ -14,8 +14,42 @@ If you are installing Rancher in a vSphere environment, refer to the best practi

 When you set up your high-availability Rancher installation, consider the following:

-### Run Rancher on a Separate Cluster
-Don't run other workloads or microservices in the Kubernetes cluster that Rancher is installed on.
+### Minimize Third-Party Software on the Upstream Cluster
+
+We generally recommend running Rancher on a dedicated cluster, free of other workloads, to avoid potential performance and compatibility issues.
+
+Rancher, especially when managing a growing number of clusters, nodes, and workloads, places a significant load on core Kubernetes components like `etcd` and `kube-apiserver` on the upstream cluster. Third-party software can interfere with the performance of these components and Rancher, potentially leading to instability.
+
+Furthermore, third-party software can functionally interfere with Rancher. To minimize compatibility risks, deploy only essential Kubernetes system components and Rancher on the upstream cluster.
+
+The following applications and components generally do not interfere with Rancher or the Kubernetes system:
+ * Rancher internal components, such as Fleet
+ * Rancher extensions
+ * Cluster API components
+ * CNIs, CPIs, CSIs
+ * Cloud controller managers
+ * Observability and monitoring tools (except prometheus-rancher-exporter)
+
+Note that each of these components has its own minimum resource requirements, which must be met in addition to Rancher's. For high-scale deployments, also consider dedicating separate nodes to non-Rancher software using [taints and tolerations](https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/) to minimize interference.
+
+The following software can interfere with Rancher performance and is therefore discouraged on the upstream cluster:
+ * [CrossPlane](https://www.crossplane.io/)
+ * [Argo CD](https://argoproj.github.io/cd/)
+ * [Flux](https://fluxcd.io/)
+ * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+ * Container registries such as [Harbor](https://goharbor.io/), which can require significant bandwidth for serving images
+
+### Guidance for Container Registries
+
+Container registries, such as [Harbor](https://goharbor.io/), can consume significant network bandwidth when serving images. This demand increases with the number of images, the frequency of image pulls, and the quantity of clusters and container runtimes they serve. Due to this potential for interference with Rancher UI and API traffic, we recommend against running container registries on the same cluster as the Rancher management server.
+
+Regardless of your deployment strategy for a container registry, ensure sufficient bandwidth is available, ideally reserved using Quality of Service (QoS) mechanisms.
+
+Consider the following recommendations based on your needs:
+
+* **Simple Setups (HA Not a Primary Concern):** A container registry deployed as a single Virtual Machine (VM) can be a viable solution.
+* **High Availability (HA) Requirements:** We recommend running the registry in a dedicated Kubernetes cluster. All other clusters should then be configured to pull images from this centralized, HA registry.
+* **Very Large-Scale or Complex Network Topologies:** Multiple registry clusters might be necessary. These can be deployed in a hierarchical or federated model to efficiently distribute images and manage traffic.

 ### Make sure nodes are configured correctly for Kubernetes
 It's important to follow K8s and etcd best practices when deploying your nodes, including disabling swap, double checking you have full network connectivity between all machines in the cluster, using unique hostnames, MAC addresses, and product_uuids for every node, checking that all correct ports are opened, and deploying with ssd backed etcd. More details can be found in the [kubernetes docs](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#before-you-begin) and [etcd's performance op guide](https://etcd.io/docs/v3.5/op-guide/performance/).
@@ -37,4 +71,3 @@ However, metrics-driven capacity planning analysis should be the ultimate guidan
 Using Rancher, you can monitor the state and processes of your cluster nodes, Kubernetes components, and software deployments through integration with Prometheus, a leading open-source monitoring solution, and Grafana, which lets you visualize the metrics from Prometheus.

 After you [enable monitoring](../../../integrations-in-rancher/monitoring-and-alerting/monitoring-and-alerting.md) in the cluster, you can set up alerts to let you know if your cluster is approaching its capacity. You can also use the Prometheus and Grafana monitoring framework to establish a baseline for key metrics as you scale.
-
@@ -23,23 +23,7 @@ When scaling up Rancher, one typical bottleneck is resource growth in the upstre

 ### Minimizing Third-Party Software on the Upstream Cluster

-Running Rancher at scale can put significant load on internal Kubernetes components, such as `etcd` or `kubeapiserver`. Issues may arise if third-party software interferes with the performance of those components or with Rancher.
-
-Every third-party piece of software carries a risk of interference. To prevent performance issues on the upstream cluster, you should avoid running any other apps or components, beyond Kubernetes system components and Rancher itself.
-
-Software in the following categories generally won't interfere with Rancher or Kubernetes system performance:
- * Rancher internal components, such as Fleet
- * Rancher extensions
- * Cluster API components
- * CNIs
- * Cloud controller managers
- * Observability and monitoring tools (with the exception of prometheus-rancher-exporter)
-
-On the other hand, the following software are found to interfere with Rancher performance at scale:
- * [CrossPlane](https://www.crossplane.io/)
- * [Argo CD](https://argoproj.github.io/cd/)
- * [Flux](https://fluxcd.io/)
- * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+Recommendations outlined in the [general Rancher recommendations](./tips-for-running-rancher.md#minimize-third-party-software-on-the-upstream-cluster) are particularly important in a high scale context.

 ### Managing Your Object Counts

@@ -10,7 +10,7 @@ This guide contains our recommendations for running the Rancher server, and is i

 ### Recommended Architecture and Infrastructure

-Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server on a high-availability Kubernetes cluster.
+Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server for a production installation.

 ### Deployment Strategies

@@ -14,8 +14,42 @@ If you are installing Rancher in a vSphere environment, refer to the best practi

 When you set up your high-availability Rancher installation, consider the following:

-### Run Rancher on a Separate Cluster
-Don't run other workloads or microservices in the Kubernetes cluster that Rancher is installed on.
+### Minimize Third-Party Software on the Upstream Cluster
+
+We generally recommend running Rancher on a dedicated cluster, free of other workloads, to avoid potential performance and compatibility issues.
+
+Rancher, especially when managing a growing number of clusters, nodes, and workloads, places a significant load on core Kubernetes components like `etcd` and `kube-apiserver` on the upstream cluster. Third-party software can interfere with the performance of these components and Rancher, potentially leading to instability.
+
+Furthermore, third-party software can functionally interfere with Rancher. To minimize compatibility risks, deploy only essential Kubernetes system components and Rancher on the upstream cluster.
+
+The following applications and components generally do not interfere with Rancher or the Kubernetes system:
+ * Rancher internal components, such as Fleet
+ * Rancher extensions
+ * Cluster API components
+ * CNIs, CPIs, CSIs
+ * Cloud controller managers
+ * Observability and monitoring tools (except prometheus-rancher-exporter)
+
+Note that each of these components has its own minimum resource requirements, which must be met in addition to Rancher's. For high-scale deployments, also consider dedicating separate nodes to non-Rancher software using [taints and tolerations](https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/) to minimize interference.
+
+The following software can interfere with Rancher performance and is therefore discouraged on the upstream cluster:
+ * [CrossPlane](https://www.crossplane.io/)
+ * [Argo CD](https://argoproj.github.io/cd/)
+ * [Flux](https://fluxcd.io/)
+ * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+ * Container registries such as [Harbor](https://goharbor.io/), which can require significant bandwidth for serving images
+
+### Guidance for Container Registries
+
+Container registries, such as [Harbor](https://goharbor.io/), can consume significant network bandwidth when serving images. This demand increases with the number of images, the frequency of image pulls, and the quantity of clusters and container runtimes they serve. Due to this potential for interference with Rancher UI and API traffic, we recommend against running container registries on the same cluster as the Rancher management server.
+
+Regardless of your deployment strategy for a container registry, ensure sufficient bandwidth is available, ideally reserved using Quality of Service (QoS) mechanisms.
+
+Consider the following recommendations based on your needs:
+
+* **Simple Setups (HA Not a Primary Concern):** A container registry deployed as a single Virtual Machine (VM) can be a viable solution.
+* **High Availability (HA) Requirements:** We recommend running the registry in a dedicated Kubernetes cluster. All other clusters should then be configured to pull images from this centralized, HA registry.
+* **Very Large-Scale or Complex Network Topologies:** Multiple registry clusters might be necessary. These can be deployed in a hierarchical or federated model to efficiently distribute images and manage traffic.

 ### Make sure nodes are configured correctly for Kubernetes
 It's important to follow K8s and etcd best practices when deploying your nodes, including disabling swap, double checking you have full network connectivity between all machines in the cluster, using unique hostnames, MAC addresses, and product_uuids for every node, checking that all correct ports are opened, and deploying with ssd backed etcd. More details can be found in the [kubernetes docs](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#before-you-begin) and [etcd's performance op guide](https://etcd.io/docs/v3.5/op-guide/performance/).
@@ -37,4 +71,3 @@ However, metrics-driven capacity planning analysis should be the ultimate guidan
 Using Rancher, you can monitor the state and processes of your cluster nodes, Kubernetes components, and software deployments through integration with Prometheus, a leading open-source monitoring solution, and Grafana, which lets you visualize the metrics from Prometheus.

 After you [enable monitoring](../../../integrations-in-rancher/monitoring-and-alerting/monitoring-and-alerting.md) in the cluster, you can set up alerts to let you know if your cluster is approaching its capacity. You can also use the Prometheus and Grafana monitoring framework to establish a baseline for key metrics as you scale.
-
@@ -23,23 +23,7 @@ When scaling up Rancher, one typical bottleneck is resource growth in the upstre

 ### Minimizing Third-Party Software on the Upstream Cluster

-Running Rancher at scale can put significant load on internal Kubernetes components, such as `etcd` or `kubeapiserver`. Issues may arise if third-party software interferes with the performance of those components or with Rancher.
-
-Every third-party piece of software carries a risk of interference. To prevent performance issues on the upstream cluster, you should avoid running any other apps or components, beyond Kubernetes system components and Rancher itself.
-
-Software in the following categories generally won't interfere with Rancher or Kubernetes system performance:
- * Rancher internal components, such as Fleet
- * Rancher extensions
- * Cluster API components
- * CNIs
- * Cloud controller managers
- * Observability and monitoring tools (with the exception of prometheus-rancher-exporter)
-
-On the other hand, the following software are found to interfere with Rancher performance at scale:
- * [CrossPlane](https://www.crossplane.io/)
- * [Argo CD](https://argoproj.github.io/cd/)
- * [Flux](https://fluxcd.io/)
- * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+Recommendations outlined in the [general Rancher recommendations](./tips-for-running-rancher.md#minimize-third-party-software-on-the-upstream-cluster) are particularly important in a high scale context.

 ### Managing Your Object Counts

@@ -10,7 +10,7 @@ This guide contains our recommendations for running the Rancher server, and is i

 ### Recommended Architecture and Infrastructure

-Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server on a high-availability Kubernetes cluster.
+Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server for a production installation.

 ### Deployment Strategies

@@ -14,8 +14,42 @@ If you are installing Rancher in a vSphere environment, refer to the best practi

 When you set up your high-availability Rancher installation, consider the following:

-### Run Rancher on a Separate Cluster
-Don't run other workloads or microservices in the Kubernetes cluster that Rancher is installed on.
+### Minimize Third-Party Software on the Upstream Cluster
+
+We generally recommend running Rancher on a dedicated cluster, free of other workloads, to avoid potential performance and compatibility issues.
+
+Rancher, especially when managing a growing number of clusters, nodes, and workloads, places a significant load on core Kubernetes components like `etcd` and `kube-apiserver` on the upstream cluster. Third-party software can interfere with the performance of these components and Rancher, potentially leading to instability.
+
+Furthermore, third-party software can functionally interfere with Rancher. To minimize compatibility risks, deploy only essential Kubernetes system components and Rancher on the upstream cluster.
+
+The following applications and components generally do not interfere with Rancher or the Kubernetes system:
+ * Rancher internal components, such as Fleet
+ * Rancher extensions
+ * Cluster API components
+ * CNIs, CPIs, CSIs
+ * Cloud controller managers
+ * Observability and monitoring tools (except prometheus-rancher-exporter)
+
+Note that each of these components has its own minimum resource requirements, which must be met in addition to Rancher's. For high-scale deployments, also consider dedicating separate nodes to non-Rancher software using [taints and tolerations](https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/) to minimize interference.
+
+The following software can interfere with Rancher performance and is therefore discouraged on the upstream cluster:
+ * [CrossPlane](https://www.crossplane.io/)
+ * [Argo CD](https://argoproj.github.io/cd/)
+ * [Flux](https://fluxcd.io/)
+ * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+ * Container registries such as [Harbor](https://goharbor.io/), which can require significant bandwidth for serving images
+
+### Guidance for Container Registries
+
+Container registries, such as [Harbor](https://goharbor.io/), can consume significant network bandwidth when serving images. This demand increases with the number of images, the frequency of image pulls, and the quantity of clusters and container runtimes they serve. Due to this potential for interference with Rancher UI and API traffic, we recommend against running container registries on the same cluster as the Rancher management server.
+
+Regardless of your deployment strategy for a container registry, ensure sufficient bandwidth is available, ideally reserved using Quality of Service (QoS) mechanisms.
+
+Consider the following recommendations based on your needs:
+
+* **Simple Setups (HA Not a Primary Concern):** A container registry deployed as a single Virtual Machine (VM) can be a viable solution.
+* **High Availability (HA) Requirements:** We recommend running the registry in a dedicated Kubernetes cluster. All other clusters should then be configured to pull images from this centralized, HA registry.
+* **Very Large-Scale or Complex Network Topologies:** Multiple registry clusters might be necessary. These can be deployed in a hierarchical or federated model to efficiently distribute images and manage traffic.

 ### Make sure nodes are configured correctly for Kubernetes
 It's important to follow K8s and etcd best practices when deploying your nodes, including disabling swap, double checking you have full network connectivity between all machines in the cluster, using unique hostnames, MAC addresses, and product_uuids for every node, checking that all correct ports are opened, and deploying with ssd backed etcd. More details can be found in the [kubernetes docs](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#before-you-begin) and [etcd's performance op guide](https://etcd.io/docs/v3.5/op-guide/performance/).
@@ -37,4 +71,3 @@ However, metrics-driven capacity planning analysis should be the ultimate guidan
 Using Rancher, you can monitor the state and processes of your cluster nodes, Kubernetes components, and software deployments through integration with Prometheus, a leading open-source monitoring solution, and Grafana, which lets you visualize the metrics from Prometheus.

 After you [enable monitoring](../../../integrations-in-rancher/monitoring-and-alerting/monitoring-and-alerting.md) in the cluster, you can set up alerts to let you know if your cluster is approaching its capacity. You can also use the Prometheus and Grafana monitoring framework to establish a baseline for key metrics as you scale.
-
@@ -23,23 +23,7 @@ When scaling up Rancher, one typical bottleneck is resource growth in the upstre

 ### Minimizing Third-Party Software on the Upstream Cluster

-Running Rancher at scale can put significant load on internal Kubernetes components, such as `etcd` or `kubeapiserver`. Issues may arise if third-party software interferes with the performance of those components or with Rancher.
-
-Every third-party piece of software carries a risk of interference. To prevent performance issues on the upstream cluster, you should avoid running any other apps or components, beyond Kubernetes system components and Rancher itself.
-
-Software in the following categories generally won't interfere with Rancher or Kubernetes system performance:
- * Rancher internal components, such as Fleet
- * Rancher extensions
- * Cluster API components
- * CNIs
- * Cloud controller managers
- * Observability and monitoring tools (with the exception of prometheus-rancher-exporter)
-
-On the other hand, the following software are found to interfere with Rancher performance at scale:
- * [CrossPlane](https://www.crossplane.io/)
- * [Argo CD](https://argoproj.github.io/cd/)
- * [Flux](https://fluxcd.io/)
- * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+Recommendations outlined in the [general Rancher recommendations](./tips-for-running-rancher.md#minimize-third-party-software-on-the-upstream-cluster) are particularly important in a high scale context.

 ### Managing Your Object Counts

@@ -10,7 +10,7 @@ This guide contains our recommendations for running the Rancher server, and is i

 ### Recommended Architecture and Infrastructure

-Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server on a high-availability Kubernetes cluster.
+Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server for a production installation.

 ### Deployment Strategies

@@ -14,8 +14,42 @@ If you are installing Rancher in a vSphere environment, refer to the best practi

 When you set up your high-availability Rancher installation, consider the following:

-### Run Rancher on a Separate Cluster
-Don't run other workloads or microservices in the Kubernetes cluster that Rancher is installed on.
+### Minimize Third-Party Software on the Upstream Cluster
+
+We generally recommend running Rancher on a dedicated cluster, free of other workloads, to avoid potential performance and compatibility issues.
+
+Rancher, especially when managing a growing number of clusters, nodes, and workloads, places a significant load on core Kubernetes components like `etcd` and `kube-apiserver` on the upstream cluster. Third-party software can interfere with the performance of these components and Rancher, potentially leading to instability.
+
+Furthermore, third-party software can functionally interfere with Rancher. To minimize compatibility risks, deploy only essential Kubernetes system components and Rancher on the upstream cluster.
+
+The following applications and components generally do not interfere with Rancher or the Kubernetes system:
+ * Rancher internal components, such as Fleet
+ * Rancher extensions
+ * Cluster API components
+ * CNIs, CPIs, CSIs
+ * Cloud controller managers
+ * Observability and monitoring tools (except prometheus-rancher-exporter)
+
+Note that each of these components has its own minimum resource requirements, which must be met in addition to Rancher's. For high-scale deployments, also consider dedicating separate nodes to non-Rancher software using [taints and tolerations](https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/) to minimize interference.
+
+The following software can interfere with Rancher performance and is therefore discouraged on the upstream cluster:
+ * [CrossPlane](https://www.crossplane.io/)
+ * [Argo CD](https://argoproj.github.io/cd/)
+ * [Flux](https://fluxcd.io/)
+ * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+ * Container registries such as [Harbor](https://goharbor.io/), which can require significant bandwidth for serving images
+
+### Guidance for Container Registries
+
+Container registries, such as [Harbor](https://goharbor.io/), can consume significant network bandwidth when serving images. This demand increases with the number of images, the frequency of image pulls, and the quantity of clusters and container runtimes they serve. Due to this potential for interference with Rancher UI and API traffic, we recommend against running container registries on the same cluster as the Rancher management server.
+
+Regardless of your deployment strategy for a container registry, ensure sufficient bandwidth is available, ideally reserved using Quality of Service (QoS) mechanisms.
+
+Consider the following recommendations based on your needs:
+
+* **Simple Setups (HA Not a Primary Concern):** A container registry deployed as a single Virtual Machine (VM) can be a viable solution.
+* **High Availability (HA) Requirements:** We recommend running the registry in a dedicated Kubernetes cluster. All other clusters should then be configured to pull images from this centralized, HA registry.
+* **Very Large-Scale or Complex Network Topologies:** Multiple registry clusters might be necessary. These can be deployed in a hierarchical or federated model to efficiently distribute images and manage traffic.

 ### Make sure nodes are configured correctly for Kubernetes
 It's important to follow K8s and etcd best practices when deploying your nodes, including disabling swap, double checking you have full network connectivity between all machines in the cluster, using unique hostnames, MAC addresses, and product_uuids for every node, checking that all correct ports are opened, and deploying with ssd backed etcd. More details can be found in the [kubernetes docs](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#before-you-begin) and [etcd's performance op guide](https://etcd.io/docs/v3.5/op-guide/performance/).
@@ -37,4 +71,3 @@ However, metrics-driven capacity planning analysis should be the ultimate guidan
 Using Rancher, you can monitor the state and processes of your cluster nodes, Kubernetes components, and software deployments through integration with Prometheus, a leading open-source monitoring solution, and Grafana, which lets you visualize the metrics from Prometheus.

 After you [enable monitoring](../../../integrations-in-rancher/monitoring-and-alerting/monitoring-and-alerting.md) in the cluster, you can set up alerts to let you know if your cluster is approaching its capacity. You can also use the Prometheus and Grafana monitoring framework to establish a baseline for key metrics as you scale.
-
@@ -23,23 +23,7 @@ When scaling up Rancher, one typical bottleneck is resource growth in the upstre

 ### Minimizing Third-Party Software on the Upstream Cluster

-Running Rancher at scale can put significant load on internal Kubernetes components, such as `etcd` or `kubeapiserver`. Issues may arise if third-party software interferes with the performance of those components or with Rancher.
-
-Every third-party piece of software carries a risk of interference. To prevent performance issues on the upstream cluster, you should avoid running any other apps or components, beyond Kubernetes system components and Rancher itself.
-
-Software in the following categories generally won't interfere with Rancher or Kubernetes system performance:
- * Rancher internal components, such as Fleet
- * Rancher extensions
- * Cluster API components
- * CNIs
- * Cloud controller managers
- * Observability and monitoring tools (with the exception of prometheus-rancher-exporter)
-
-On the other hand, the following software are found to interfere with Rancher performance at scale:
- * [CrossPlane](https://www.crossplane.io/)
- * [Argo CD](https://argoproj.github.io/cd/)
- * [Flux](https://fluxcd.io/)
- * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+Recommendations outlined in the [general Rancher recommendations](./tips-for-running-rancher.md#minimize-third-party-software-on-the-upstream-cluster) are particularly important in a high scale context.

 ### Managing Your Object Counts

@@ -10,7 +10,7 @@ This guide contains our recommendations for running the Rancher server, and is i

 ### Recommended Architecture and Infrastructure

-Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server on a high-availability Kubernetes cluster.
+Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server for a production installation.

 ### Deployment Strategies

@@ -14,8 +14,42 @@ If you are installing Rancher in a vSphere environment, refer to the best practi

 When you set up your high-availability Rancher installation, consider the following:

-### Run Rancher on a Separate Cluster
-Don't run other workloads or microservices in the Kubernetes cluster that Rancher is installed on.
+### Minimize Third-Party Software on the Upstream Cluster
+
+We generally recommend running Rancher on a dedicated cluster, free of other workloads, to avoid potential performance and compatibility issues.
+
+Rancher, especially when managing a growing number of clusters, nodes, and workloads, places a significant load on core Kubernetes components like `etcd` and `kube-apiserver` on the upstream cluster. Third-party software can interfere with the performance of these components and Rancher, potentially leading to instability.
+
+Furthermore, third-party software can functionally interfere with Rancher. To minimize compatibility risks, deploy only essential Kubernetes system components and Rancher on the upstream cluster.
+
+The following applications and components generally do not interfere with Rancher or the Kubernetes system:
+ * Rancher internal components, such as Fleet
+ * Rancher extensions
+ * Cluster API components
+ * CNIs, CPIs, CSIs
+ * Cloud controller managers
+ * Observability and monitoring tools (except prometheus-rancher-exporter)
+
+Note that each of these components has its own minimum resource requirements, which must be met in addition to Rancher's. For high-scale deployments, also consider dedicating separate nodes to non-Rancher software using [taints and tolerations](https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/) to minimize interference.
+
+The following software can interfere with Rancher performance and is therefore discouraged on the upstream cluster:
+ * [CrossPlane](https://www.crossplane.io/)
+ * [Argo CD](https://argoproj.github.io/cd/)
+ * [Flux](https://fluxcd.io/)
+ * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+ * Container registries such as [Harbor](https://goharbor.io/), which can require significant bandwidth for serving images
+
+### Guidance for Container Registries
+
+Container registries, such as [Harbor](https://goharbor.io/), can consume significant network bandwidth when serving images. This demand increases with the number of images, the frequency of image pulls, and the quantity of clusters and container runtimes they serve. Due to this potential for interference with Rancher UI and API traffic, we recommend against running container registries on the same cluster as the Rancher management server.
+
+Regardless of your deployment strategy for a container registry, ensure sufficient bandwidth is available, ideally reserved using Quality of Service (QoS) mechanisms.
+
+Consider the following recommendations based on your needs:
+
+* **Simple Setups (HA Not a Primary Concern):** A container registry deployed as a single Virtual Machine (VM) can be a viable solution.
+* **High Availability (HA) Requirements:** We recommend running the registry in a dedicated Kubernetes cluster. All other clusters should then be configured to pull images from this centralized, HA registry.
+* **Very Large-Scale or Complex Network Topologies:** Multiple registry clusters might be necessary. These can be deployed in a hierarchical or federated model to efficiently distribute images and manage traffic.

 ### Make sure nodes are configured correctly for Kubernetes
 It's important to follow K8s and etcd best practices when deploying your nodes, including disabling swap, double checking you have full network connectivity between all machines in the cluster, using unique hostnames, MAC addresses, and product_uuids for every node, checking that all correct ports are opened, and deploying with ssd backed etcd. More details can be found in the [kubernetes docs](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#before-you-begin) and [etcd's performance op guide](https://etcd.io/docs/v3.5/op-guide/performance/).
@@ -37,4 +71,3 @@ However, metrics-driven capacity planning analysis should be the ultimate guidan
 Using Rancher, you can monitor the state and processes of your cluster nodes, Kubernetes components, and software deployments through integration with Prometheus, a leading open-source monitoring solution, and Grafana, which lets you visualize the metrics from Prometheus.

 After you [enable monitoring](../../../integrations-in-rancher/monitoring-and-alerting/monitoring-and-alerting.md) in the cluster, you can set up alerts to let you know if your cluster is approaching its capacity. You can also use the Prometheus and Grafana monitoring framework to establish a baseline for key metrics as you scale.
-
@@ -23,23 +23,7 @@ When scaling up Rancher, one typical bottleneck is resource growth in the upstre

 ### Minimizing Third-Party Software on the Upstream Cluster

-Running Rancher at scale can put significant load on internal Kubernetes components, such as `etcd` or `kubeapiserver`. Issues may arise if third-party software interferes with the performance of those components or with Rancher.
-
-Every third-party piece of software carries a risk of interference. To prevent performance issues on the upstream cluster, you should avoid running any other apps or components, beyond Kubernetes system components and Rancher itself.
-
-Software in the following categories generally won't interfere with Rancher or Kubernetes system performance:
- * Rancher internal components, such as Fleet
- * Rancher extensions
- * Cluster API components
- * CNIs
- * Cloud controller managers
- * Observability and monitoring tools (with the exception of prometheus-rancher-exporter)
-
-On the other hand, the following software are found to interfere with Rancher performance at scale:
- * [CrossPlane](https://www.crossplane.io/)
- * [Argo CD](https://argoproj.github.io/cd/)
- * [Flux](https://fluxcd.io/)
- * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+Recommendations outlined in the [general Rancher recommendations](./tips-for-running-rancher.md#minimize-third-party-software-on-the-upstream-cluster) are particularly important in a high scale context.

 ### Managing Your Object Counts

@@ -10,7 +10,7 @@ This guide contains our recommendations for running the Rancher server, and is i

 ### Recommended Architecture and Infrastructure

-Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server on a high-availability Kubernetes cluster.
+Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server for a production installation.

 ### Deployment Strategies

@@ -14,8 +14,42 @@ If you are installing Rancher in a vSphere environment, refer to the best practi

 When you set up your high-availability Rancher installation, consider the following:

-### Run Rancher on a Separate Cluster
-Don't run other workloads or microservices in the Kubernetes cluster that Rancher is installed on.
+### Minimize Third-Party Software on the Upstream Cluster
+
+We generally recommend running Rancher on a dedicated cluster, free of other workloads, to avoid potential performance and compatibility issues.
+
+Rancher, especially when managing a growing number of clusters, nodes, and workloads, places a significant load on core Kubernetes components like `etcd` and `kube-apiserver` on the upstream cluster. Third-party software can interfere with the performance of these components and Rancher, potentially leading to instability.
+
+Furthermore, third-party software can functionally interfere with Rancher. To minimize compatibility risks, deploy only essential Kubernetes system components and Rancher on the upstream cluster.
+
+The following applications and components generally do not interfere with Rancher or the Kubernetes system:
+ * Rancher internal components, such as Fleet
+ * Rancher extensions
+ * Cluster API components
+ * CNIs, CPIs, CSIs
+ * Cloud controller managers
+ * Observability and monitoring tools (except prometheus-rancher-exporter)
+
+Note that each of these components has its own minimum resource requirements, which must be met in addition to Rancher's. For high-scale deployments, also consider dedicating separate nodes to non-Rancher software using [taints and tolerations](https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/) to minimize interference.
+
+The following software can interfere with Rancher performance and is therefore discouraged on the upstream cluster:
+ * [CrossPlane](https://www.crossplane.io/)
+ * [Argo CD](https://argoproj.github.io/cd/)
+ * [Flux](https://fluxcd.io/)
+ * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+ * Container registries such as [Harbor](https://goharbor.io/), which can require significant bandwidth for serving images
+
+### Guidance for Container Registries
+
+Container registries, such as [Harbor](https://goharbor.io/), can consume significant network bandwidth when serving images. This demand increases with the number of images, the frequency of image pulls, and the quantity of clusters and container runtimes they serve. Due to this potential for interference with Rancher UI and API traffic, we recommend against running container registries on the same cluster as the Rancher management server.
+
+Regardless of your deployment strategy for a container registry, ensure sufficient bandwidth is available, ideally reserved using Quality of Service (QoS) mechanisms.
+
+Consider the following recommendations based on your needs:
+
+* **Simple Setups (HA Not a Primary Concern):** A container registry deployed as a single Virtual Machine (VM) can be a viable solution.
+* **High Availability (HA) Requirements:** We recommend running the registry in a dedicated Kubernetes cluster. All other clusters should then be configured to pull images from this centralized, HA registry.
+* **Very Large-Scale or Complex Network Topologies:** Multiple registry clusters might be necessary. These can be deployed in a hierarchical or federated model to efficiently distribute images and manage traffic.

 ### Make sure nodes are configured correctly for Kubernetes
 It's important to follow K8s and etcd best practices when deploying your nodes, including disabling swap, double checking you have full network connectivity between all machines in the cluster, using unique hostnames, MAC addresses, and product_uuids for every node, checking that all correct ports are opened, and deploying with ssd backed etcd. More details can be found in the [kubernetes docs](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#before-you-begin) and [etcd's performance op guide](https://etcd.io/docs/v3.5/op-guide/performance/).
@@ -37,4 +71,3 @@ However, metrics-driven capacity planning analysis should be the ultimate guidan
 Using Rancher, you can monitor the state and processes of your cluster nodes, Kubernetes components, and software deployments through integration with Prometheus, a leading open-source monitoring solution, and Grafana, which lets you visualize the metrics from Prometheus.

 After you [enable monitoring](../../../integrations-in-rancher/monitoring-and-alerting/monitoring-and-alerting.md) in the cluster, you can set up alerts to let you know if your cluster is approaching its capacity. You can also use the Prometheus and Grafana monitoring framework to establish a baseline for key metrics as you scale.
-
@@ -23,23 +23,7 @@ When scaling up Rancher, one typical bottleneck is resource growth in the upstre

 ### Minimizing Third-Party Software on the Upstream Cluster

-Running Rancher at scale can put significant load on internal Kubernetes components, such as `etcd` or `kubeapiserver`. Issues may arise if third-party software interferes with the performance of those components or with Rancher.
-
-Every third-party piece of software carries a risk of interference. To prevent performance issues on the upstream cluster, you should avoid running any other apps or components, beyond Kubernetes system components and Rancher itself.
-
-Software in the following categories generally won't interfere with Rancher or Kubernetes system performance:
- * Rancher internal components, such as Fleet
- * Rancher extensions
- * Cluster API components
- * CNIs
- * Cloud controller managers
- * Observability and monitoring tools (with the exception of prometheus-rancher-exporter)
-
-On the other hand, the following software are found to interfere with Rancher performance at scale:
- * [CrossPlane](https://www.crossplane.io/)
- * [Argo CD](https://argoproj.github.io/cd/)
- * [Flux](https://fluxcd.io/)
- * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+Recommendations outlined in the [general Rancher recommendations](./tips-for-running-rancher.md#minimize-third-party-software-on-the-upstream-cluster) are particularly important in a high scale context.

 ### Managing Your Object Counts

@@ -10,7 +10,7 @@ This guide contains our recommendations for running the Rancher server, and is i

 ### Recommended Architecture and Infrastructure

-Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server on a high-availability Kubernetes cluster.
+Refer to this [guide](tips-for-running-rancher.md) for our general advice for setting up the Rancher server for a production installation.

 ### Deployment Strategies

@@ -14,8 +14,42 @@ If you are installing Rancher in a vSphere environment, refer to the best practi

 When you set up your high-availability Rancher installation, consider the following:

-### Run Rancher on a Separate Cluster
-Don't run other workloads or microservices in the Kubernetes cluster that Rancher is installed on.
+### Minimize Third-Party Software on the Upstream Cluster
+
+We generally recommend running Rancher on a dedicated cluster, free of other workloads, to avoid potential performance and compatibility issues.
+
+Rancher, especially when managing a growing number of clusters, nodes, and workloads, places a significant load on core Kubernetes components like `etcd` and `kube-apiserver` on the upstream cluster. Third-party software can interfere with the performance of these components and Rancher, potentially leading to instability.
+
+Furthermore, third-party software can functionally interfere with Rancher. To minimize compatibility risks, deploy only essential Kubernetes system components and Rancher on the upstream cluster.
+
+The following applications and components generally do not interfere with Rancher or the Kubernetes system:
+ * Rancher internal components, such as Fleet
+ * Rancher extensions
+ * Cluster API components
+ * CNIs, CPIs, CSIs
+ * Cloud controller managers
+ * Observability and monitoring tools (except prometheus-rancher-exporter)
+
+Note that each of these components has its own minimum resource requirements, which must be met in addition to Rancher's. For high-scale deployments, also consider dedicating separate nodes to non-Rancher software using [taints and tolerations](https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/) to minimize interference.
+
+The following software can interfere with Rancher performance and is therefore discouraged on the upstream cluster:
+ * [CrossPlane](https://www.crossplane.io/)
+ * [Argo CD](https://argoproj.github.io/cd/)
+ * [Flux](https://fluxcd.io/)
+ * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+ * Container registries such as [Harbor](https://goharbor.io/), which can require significant bandwidth for serving images
+
+### Guidance for Container Registries
+
+Container registries, such as [Harbor](https://goharbor.io/), can consume significant network bandwidth when serving images. This demand increases with the number of images, the frequency of image pulls, and the quantity of clusters and container runtimes they serve. Due to this potential for interference with Rancher UI and API traffic, we recommend against running container registries on the same cluster as the Rancher management server.
+
+Regardless of your deployment strategy for a container registry, ensure sufficient bandwidth is available, ideally reserved using Quality of Service (QoS) mechanisms.
+
+Consider the following recommendations based on your needs:
+
+* **Simple Setups (HA Not a Primary Concern):** A container registry deployed as a single Virtual Machine (VM) can be a viable solution.
+* **High Availability (HA) Requirements:** We recommend running the registry in a dedicated Kubernetes cluster. All other clusters should then be configured to pull images from this centralized, HA registry.
+* **Very Large-Scale or Complex Network Topologies:** Multiple registry clusters might be necessary. These can be deployed in a hierarchical or federated model to efficiently distribute images and manage traffic.

 ### Make sure nodes are configured correctly for Kubernetes
 It's important to follow K8s and etcd best practices when deploying your nodes, including disabling swap, double checking you have full network connectivity between all machines in the cluster, using unique hostnames, MAC addresses, and product_uuids for every node, checking that all correct ports are opened, and deploying with ssd backed etcd. More details can be found in the [kubernetes docs](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#before-you-begin) and [etcd's performance op guide](https://etcd.io/docs/v3.5/op-guide/performance/).
@@ -37,4 +71,3 @@ However, metrics-driven capacity planning analysis should be the ultimate guidan
 Using Rancher, you can monitor the state and processes of your cluster nodes, Kubernetes components, and software deployments through integration with Prometheus, a leading open-source monitoring solution, and Grafana, which lets you visualize the metrics from Prometheus.

 After you [enable monitoring](../../../integrations-in-rancher/monitoring-and-alerting/monitoring-and-alerting.md) in the cluster, you can set up alerts to let you know if your cluster is approaching its capacity. You can also use the Prometheus and Grafana monitoring framework to establish a baseline for key metrics as you scale.
-
@@ -23,23 +23,7 @@ When scaling up Rancher, one typical bottleneck is resource growth in the upstre

 ### Minimizing Third-Party Software on the Upstream Cluster

-Running Rancher at scale can put significant load on internal Kubernetes components, such as `etcd` or `kubeapiserver`. Issues may arise if third-party software interferes with the performance of those components or with Rancher.
-
-Every third-party piece of software carries a risk of interference. To prevent performance issues on the upstream cluster, you should avoid running any other apps or components, beyond Kubernetes system components and Rancher itself.
-
-Software in the following categories generally won't interfere with Rancher or Kubernetes system performance:
- * Rancher internal components, such as Fleet
- * Rancher extensions
- * Cluster API components
- * CNIs
- * Cloud controller managers
- * Observability and monitoring tools (with the exception of prometheus-rancher-exporter)
-
-On the other hand, the following software are found to interfere with Rancher performance at scale:
- * [CrossPlane](https://www.crossplane.io/)
- * [Argo CD](https://argoproj.github.io/cd/)
- * [Flux](https://fluxcd.io/)
- * [prometheus-rancher-exporter](https://github.com/David-VTUK/prometheus-rancher-exporter) (see [issue 33](https://github.com/David-VTUK/prometheus-rancher-exporter/issues/33))
+Recommendations outlined in the [general Rancher recommendations](./tips-for-running-rancher.md#minimize-third-party-software-on-the-upstream-cluster) are particularly important in a high scale context.

 ### Managing Your Object Counts