{"id":88,"date":"2024-04-01T07:50:54","date_gmt":"2024-04-01T07:50:54","guid":{"rendered":"https:\/\/oneboxinthecloud.com\/?p=88"},"modified":"2024-09-09T10:09:51","modified_gmt":"2024-09-09T10:09:51","slug":"stretched-cluster-design","status":"publish","type":"post","link":"https:\/\/oneboxinthecloud.com\/index.php\/2024\/04\/01\/stretched-cluster-design\/","title":{"rendered":"Distributed Telco Cloud Architecture – Part 3 -Stretched cluster design"},"content":{"rendered":"\n

In the case of the RAN environment we have to design stretched cluster for the DU workloads.<\/p>\n\n\n\n

From TCP RA 3.1 guide, stretched cluster is defined as below
If you create a Tanzu Kubernetes cluster where node pools are deployed to different target endpoints (within a single vCenter), it is called a Stretched Cluster. In this scenario, multiple vSphere endpoints are used as target endpoints for different node pools within a single cluster.<\/p>\n\n\n\n

There are some conditions that needs to be met while configuring such a topology i.e.
When using stretched cluster designs, storage zoning is required if the datastores on each vSphere cluster are unique (as with a vSAN design). This ensures that node pools within a resource pool on a vSphere Cluster or standalone host can consume the appropriate storage for any persistent volume claims the cluster might need.<\/p>\n\n\n\n

Without this configuration the DU instantiation will fail.<\/p>\n\n\n\n

\"\"
No storage aware configuration (Design credits Hiroshi Ohno san)<\/figcaption><\/figure>\n\n\n\n

While enabling multi-zone, we have to ensure that 
For region: vSphere data center has tags attached for the selected category. 
For zone: vSphere Cluster or hosts under the vSphere cluster has tags attached for the selected category.
Ensure that vSphere Cluster and hosts under vSphere cluster does not share the same tags.<\/p>\n\n\n\n

The topology for the same can be drawn like below <\/p>\n\n\n\n

\"\"
vSphere cluster design logical view<\/figcaption><\/figure>\n\n\n\n

 <\/p>\n\n\n\n

Categories can be defined in vSphere Client > \u2018Tags & Custom Attributes\u2019 > Categories tab
e.g. k8s-zone for clusters & individual hosts, k8s-region for datacenter<\/p>\n\n\n\n

\"\"
Tags & Custom Attributes Categories<\/figcaption><\/figure>\n\n\n\n

Tags can be defined in vSphere Client > \u2018Tags & Custom Attributes\u2019 > Tags tab
e.g. Tag region-dc can be defined for vcenter_datacenter & assigned Category k8s-region
Tag zone-cls can be defined for vcenter_cluster_vsan_configured & assigned Category k8s-zone
Tag zone-host4 can be defined for Host4_local_datastore & assigned Category k8s-zone
Tag zone-host5 can be defined for Host5_local_datastore & assigned Category k8s-zone
i.e.<\/p>\n\n\n\n

\"\"
vSphere cluster design logical view with Tags & Categories<\/figcaption><\/figure>\n\n\n\n
\"\"
Storage aware configuration (Diagram credits Hiroshi Ohno san) <\/figcaption><\/figure>\n\n\n\n

In the workload cluster, define the zone & region categories in the vSphere-CSI add-on configuration.<\/p>\n\n\n\n

\"\"
Workload cluster Add-Ons list<\/figcaption><\/figure>\n\n\n\n
\"\"
vSphere-CSI configuration<\/figcaption><\/figure>\n\n\n\n

This configuration is important before deploying workloads, as in absence of it PV creation will fail and pods will fail to deploy (Error: failed to get shared datastore for topology).<\/p>\n\n\n\n

\"\"
Error : failed to get shared datastore<\/figcaption><\/figure>\n\n\n\n

Hoping above pointers will help in your lab activities. Cheers \ud83d\ude42<\/p>\n","protected":false},"excerpt":{"rendered":"

In the case of the RAN environment we have to design stretched cluster for the DU workloads. From TCP RA 3.1 guide, stretched cluster is defined as belowIf you create a Tanzu Kubernetes cluster where node pools are deployed to different target endpoints (within a single vCenter), it is called a Stretched Cluster. In this […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_mi_skip_tracking":false,"footnotes":""},"categories":[6],"tags":[],"class_list":["post-88","post","type-post","status-publish","format-standard","hentry","category-labassist"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/oneboxinthecloud.com\/index.php\/wp-json\/wp\/v2\/posts\/88","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oneboxinthecloud.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/oneboxinthecloud.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/oneboxinthecloud.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/oneboxinthecloud.com\/index.php\/wp-json\/wp\/v2\/comments?post=88"}],"version-history":[{"count":5,"href":"https:\/\/oneboxinthecloud.com\/index.php\/wp-json\/wp\/v2\/posts\/88\/revisions"}],"predecessor-version":[{"id":122,"href":"https:\/\/oneboxinthecloud.com\/index.php\/wp-json\/wp\/v2\/posts\/88\/revisions\/122"}],"wp:attachment":[{"href":"https:\/\/oneboxinthecloud.com\/index.php\/wp-json\/wp\/v2\/media?parent=88"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/oneboxinthecloud.com\/index.php\/wp-json\/wp\/v2\/categories?post=88"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/oneboxinthecloud.com\/index.php\/wp-json\/wp\/v2\/tags?post=88"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}