From 7a4aa2e21db7ff2fedf852c11cf4fe212cc2ea23 Mon Sep 17 00:00:00 2001 From: galal-hussein Date: Tue, 21 Jan 2020 19:49:59 +0200 Subject: [PATCH 1/2] Add sizing guide --- .../_index.md | 32 ++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) rename content/k3s/latest/en/installation/{node-requirements => installation-requirements}/_index.md (63%) diff --git a/content/k3s/latest/en/installation/node-requirements/_index.md b/content/k3s/latest/en/installation/installation-requirements/_index.md similarity index 63% rename from content/k3s/latest/en/installation/node-requirements/_index.md rename to content/k3s/latest/en/installation/installation-requirements/_index.md index 6373503c7da..7b819200caf 100644 --- a/content/k3s/latest/en/installation/node-requirements/_index.md +++ b/content/k3s/latest/en/installation/installation-requirements/_index.md @@ -1,5 +1,5 @@ --- -title: Node Requirements +title: Installation Requirements weight: 1 --- @@ -8,6 +8,7 @@ K3s is very lightweight, but has some minimum requirements as outlined below. Whether you're configuring a K3s cluster to run in a Docker or Kubernetes setup, each node running K3s should meet the following minimum requirements. You may need more resources to fit your needs. ## Prerequisites + * Two nodes cannot have the same hostname. If all your nodes have the same hostname, pass `--node-name` or set `$K3S_NODE_NAME` with a unique name for each node you add to the cluster. ## Operating Systems @@ -38,3 +39,32 @@ The K3s server needs port 6443 to be accessible by the nodes. The nodes need to IMPORTANT: The VXLAN port on nodes should not be exposed to the world as it opens up your cluster network to be accessed by anyone. Run your nodes behind a firewall/security group that disabled access to port 8472. If you wish to utilize the metrics server, you will need to open port 10250 on each node. + +## Large Clusters + +Hardware requirement is based on the size of your K3s cluster, for production and large clusters its recommended to use HA setup with external database setup, that includes: +- MySQL +- PostgreSQL +- etcd + +### CPU and Memory + +The following is the memory/cpu installation requirement recommendation for HA server nodes of K3s cluster: + +| Deployment Size | Nodes | VCPUS | RAM | +|:---------------:|:---------:|:-----:|:-----:| +| Small | Up to 10 | 2 | 4 GB | +| Medium | Up to 100 | 4 | 8 GB | +| Large | Up to 250 | 8 | 16 GB | +| X-Large | Up to 500 | 16 | 32 GB | +| XX-Large | 500+ | 32 | 64 GB | + +### Disks + +The cluster performance depends on database performance. To ensure optimal speed, we recommend always using SSD disks to back your K3s cluster. On cloud providers, you will also want to use the minimum size that allows the maximum IOPS. + +### Network + +You should consider increasing the subnet size for the cluster cidr so that you don't run out of IPs for the pods, you can do that by passing `--cluster-cidr` option to k3s server upon starting. + + From 6588cc6cbe96de6bb537c51ee82b14cabc67690c Mon Sep 17 00:00:00 2001 From: Catherine Luse Date: Fri, 28 Feb 2020 10:16:20 -0700 Subject: [PATCH 2/2] Grammar/style edit on K3s installation reqs --- .../en/installation/installation-requirements/_index.md | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/content/k3s/latest/en/installation/installation-requirements/_index.md b/content/k3s/latest/en/installation/installation-requirements/_index.md index 7b819200caf..a36d5c1f6e1 100644 --- a/content/k3s/latest/en/installation/installation-requirements/_index.md +++ b/content/k3s/latest/en/installation/installation-requirements/_index.md @@ -34,7 +34,7 @@ K3s performance depends on the performance of the database. To ensure optimal sp ## Networking -The K3s server needs port 6443 to be accessible by the nodes. The nodes need to be able to reach other nodes over UDP port 8472 (Flannel VXLAN). If you do not use flannel and provide your own custom CNI, then port 8472 is not needed by K3s. The node should not listen on any other port. K3s uses reverse tunneling such that the nodes make outbound connections to the server and all kubelet traffic runs through that tunnel. +The K3s server needs port 6443 to be accessible by the nodes. The nodes need to be able to reach other nodes over UDP port 8472 (Flannel VXLAN). If you do not use Flannel and provide your own custom CNI, then port 8472 is not needed by K3s. The node should not listen on any other port. K3s uses reverse tunneling such that the nodes make outbound connections to the server and all kubelet traffic runs through that tunnel. IMPORTANT: The VXLAN port on nodes should not be exposed to the world as it opens up your cluster network to be accessed by anyone. Run your nodes behind a firewall/security group that disabled access to port 8472. @@ -42,14 +42,14 @@ If you wish to utilize the metrics server, you will need to open port 10250 on e ## Large Clusters -Hardware requirement is based on the size of your K3s cluster, for production and large clusters its recommended to use HA setup with external database setup, that includes: +Hardware requirements are based on the size of your K3s cluster. For production and large clusters, we recommend using a high-availability setup with an external database. The following options are recommended for the external database in production: - MySQL - PostgreSQL - etcd ### CPU and Memory -The following is the memory/cpu installation requirement recommendation for HA server nodes of K3s cluster: +The following are the minimum CPU and memory requirements for nodes in a high-availability K3s server: | Deployment Size | Nodes | VCPUS | RAM | |:---------------:|:---------:|:-----:|:-----:| @@ -65,6 +65,6 @@ The cluster performance depends on database performance. To ensure optimal speed ### Network -You should consider increasing the subnet size for the cluster cidr so that you don't run out of IPs for the pods, you can do that by passing `--cluster-cidr` option to k3s server upon starting. +You should consider increasing the subnet size for the cluster CIDR so that you don't run out of IPs for the pods. You can do that by passing the `--cluster-cidr` option to K3s server upon starting.