Public Information

samples/ha/README.md

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+# High Availability
+
+To gain a higher level of availability for your Instance, you can 
+
+- create more Kubernetes Cluster Nodes
+- create more replicas of the *nscale* and *nplus* components
+- distribute those replicas across multiple nodes using anti-affinities
+
+This is how:
+
+```
+helm install \
+  --values samples/ha/values.yaml
+  --values samples/environment/demo.yaml \
+  sample-ha nplus/nplus-instance
+```
+
+The essents of the values file is this:
+
+- We use three (3) *nscale Server Application Layer*, two dedicated to user access, one dedicated to jobs
+- if the jobs node fails, the user nodes take the jobs (handled by priority)
+- if one of the user nodes fail, the other one handles the load
+- Kubernetes takes care of restarting nodes should that happen
+- All components run with two replicas
+- Pod anti-affinities handle the distribution
+- any administration component only connects to the jobs nappl, leaving the user nodes to the users
+- PodDisruptionBudgets are defined for the crutial components. These are set via `minReplicaCount` for the components that can support multiple replicas, and `minReplicaCountType` for the **first** replicaSet of the components that do not support replicas, in this case nstla.
+
+```
+web:
+  replicaCount: 2
+  minReplicaCount: 1
+rs:
+  replicaCount: 2
+  minReplicaCount: 1
+ilm:
+  replicaCount: 2
+  minReplicaCount: 1
+cmis:
+  replicaCount: 2
+  minReplicaCount: 1
+webdav:
+  replicaCount: 2
+  minReplicaCount: 1
+nstla:
+  minReplicaCountType: 1
+administrator:
+  nappl:
+    host: "{{ .component.prefix }}nappljobs.{{ .Release.Namespace }}"
+  waitFor:
+    - "-service {{ .component.prefix }}nappljobs.{{ .Release.Namespace }}.svc.cluster.local:{{ .this.nappl.port }} -timeout 600"
+pam:
+  nappl:
+    host: "{{ .component.prefix }}nappljobs.{{ .Release.Namespace }}"
+  waitFor:
+    - "-service {{ .component.prefix }}nappljobs.{{ .Release.Namespace }}.svc.cluster.local:{{ .this.nappl.port }} -timeout 600"
+nappl:
+  replicaCount: 2
+  minReplicaCount: 1
+  jobs: false
+  waitFor:
+    - "-service {{ .component.prefix }}nappljobs.{{ .Release.Namespace }}.svc.cluster.local:{{ .this.nappl.port }} -timeout 600"
+nappljobs:
+  replicaCount: 1
+  jobs: true
+  disableSessionReplication: true
+  ingress:
+    enabled: false
+  snc:
+    enabled: true
+  waitFor:
+    - "-service {{ .component.prefix }}database.{{ .Release.Namespace }}.svc.cluster.local:5432 -timeout 600"
+application:
+  nstl: 
+    host: "{{ .component.prefix }}nstl-cluster.{{ .Release.Namespace }}"
+  nappl:
+    host: "{{ .component.prefix }}nappljobs.{{ .Release.Namespace }}"
+```