openops-cloud · MarceloRGonc · Aug 13, 2026 · Aug 13, 2026 · Aug 13, 2026
diff --git a/AGENTS.md b/AGENTS.md
@@ -26,7 +26,7 @@
 - **Security-first design**: Security contexts enabled by default (runAsNonRoot, drop ALL capabilities, seccomp RuntimeDefault profile).
 - **Service accounts**: Dedicated service accounts for each component (app, engine, tables, analytics, nginx, postgres, redis) with configurable annotations for AWS IAM roles (IRSA), GCP Workload Identity, or Azure Managed Identity.
 - **External Secrets Operator**: Built-in support for AWS Secrets Manager, HashiCorp Vault, GCP Secret Manager, and Azure Key Vault integration.
-- **PodDisruptionBudgets (PDBs)**: Configured for all stateless components to ensure minimum availability during voluntary disruptions (node drains, upgrades).
+- **PodDisruptionBudgets (PDBs)**: Configured for `app`, `engine`, `nginx`, `analytics` and `tables` — note that `tables` is stateful (PVC, ReadWriteOnce), while the Postgres and Redis StatefulSets have no PDB. All default to `maxUnavailable: 1` so voluntary disruptions (node drains, upgrades) can always proceed. Each component also accepts `minAvailable` when `maxUnavailable` is unset, but avoid it where a component runs a single replica: `minAvailable: 1` then evaluates to `disruptionsAllowed: 0` and blocks every drain. `analytics` and `tables` default to one replica.
 - **HorizontalPodAutoscalers (HPAs)**: Optional autoscaling for app, engine, analytics, and nginx based on CPU/memory metrics.
 - **NetworkPolicy**: Optional network segmentation to restrict pod-to-pod communication and enforce least-privilege networking with explicit allow rules.
 - **LimitRange**: Optional namespace-level resource defaults and constraints to prevent resource exhaustion.

diff --git a/README.md b/README.md
@@ -829,26 +829,52 @@ global:
     topologyKey: topology.kubernetes.io/zone
     whenUnsatisfiable: DoNotSchedule
 
-# Enable PodDisruptionBudgets
-pdb:
-  enabled: true
-  app:
+# PodDisruptionBudgets are enabled by default with maxUnavailable: 1
+app:
+  podDisruptionBudget:
     enabled: true
-    minAvailable: 2
-  engine:
+    maxUnavailable: 1
+engine:
+  podDisruptionBudget:
     enabled: true
-    minAvailable: 2
-  nginx:
+    maxUnavailable: 1
+nginx:
+  podDisruptionBudget:
     enabled: true
-    minAvailable: 1
-  analytics:
+    maxUnavailable: 1
+analytics:
+  podDisruptionBudget:
     enabled: true
-    minAvailable: 1
-  tables:
+    maxUnavailable: 1
+tables:
+  podDisruptionBudget:
     enabled: true
-    minAvailable: 1
+    maxUnavailable: 1
+```
+
+A PodDisruptionBudget resource carries only one of the two fields. The chart renders
+`maxUnavailable` whenever that value is non-nil, and `minAvailable` otherwise;
+`maxUnavailable: 0` counts as set and is rendered as `0`.
+
+Prefer `maxUnavailable`. `minAvailable: 1` on a component running a single replica
+evaluates to `disruptionsAllowed: 0`, which makes the pod impossible to evict and blocks
+every node drain — cluster upgrades, node image upgrades and autoscaler scale-down all
+fail while it is set. `analytics` and `tables` default to one replica, and `tables` uses
+`ReadWriteOnce` storage so it cannot be scaled out of the problem.
+
+To use `minAvailable` instead, set `maxUnavailable` to `null` explicitly:
+
+```yaml
+app:
+  podDisruptionBudget:
+    maxUnavailable: null
+    minAvailable: 2
 ```
 
+Note that `maxUnavailable: 1` allows only one pod down at a time. At three or more
+replicas that is stricter than `minAvailable: 1`, which permits all but one to go at
+once — safer, but drains take longer.
+
 ### Monitoring and observability
 
 **Prometheus metrics:**

diff --git a/chart/templates/pdb-analytics.yaml b/chart/templates/pdb-analytics.yaml
@@ -9,7 +9,11 @@ metadata:
     {{- toYaml . | nindent 4 }}
     {{- end }}
 spec:
-  minAvailable: {{ .Values.analytics.podDisruptionBudget.minAvailable }}
+  {{- if not (kindIs "invalid" .Values.analytics.podDisruptionBudget.maxUnavailable) }}
+  maxUnavailable: {{ .Values.analytics.podDisruptionBudget.maxUnavailable }}
+  {{- else }}
+  minAvailable: {{ .Values.analytics.podDisruptionBudget.minAvailable | default 1 }}
+  {{- end }}
   selector:
     matchLabels:
       {{- include "openops.componentSelectorLabels" (dict "root" . "component" "analytics") | nindent 6 }}

diff --git a/chart/templates/pdb-app.yaml b/chart/templates/pdb-app.yaml
@@ -9,7 +9,11 @@ metadata:
     {{- toYaml . | nindent 4 }}
     {{- end }}
 spec:
-  minAvailable: {{ .Values.app.podDisruptionBudget.minAvailable }}
+  {{- if not (kindIs "invalid" .Values.app.podDisruptionBudget.maxUnavailable) }}
+  maxUnavailable: {{ .Values.app.podDisruptionBudget.maxUnavailable }}
+  {{- else }}
+  minAvailable: {{ .Values.app.podDisruptionBudget.minAvailable | default 1 }}
+  {{- end }}
   selector:
     matchLabels:
       {{- include "openops.componentSelectorLabels" (dict "root" . "component" "app") | nindent 6 }}

diff --git a/chart/templates/pdb-engine.yaml b/chart/templates/pdb-engine.yaml
@@ -9,7 +9,11 @@ metadata:
     {{- toYaml . | nindent 4 }}
     {{- end }}
 spec:
-  minAvailable: {{ .Values.engine.podDisruptionBudget.minAvailable }}
+  {{- if not (kindIs "invalid" .Values.engine.podDisruptionBudget.maxUnavailable) }}
+  maxUnavailable: {{ .Values.engine.podDisruptionBudget.maxUnavailable }}
+  {{- else }}
+  minAvailable: {{ .Values.engine.podDisruptionBudget.minAvailable | default 1 }}
+  {{- end }}
   selector:
     matchLabels:
       {{- include "openops.componentSelectorLabels" (dict "root" . "component" "engine") | nindent 6 }}

diff --git a/chart/templates/pdb-nginx.yaml b/chart/templates/pdb-nginx.yaml
@@ -9,7 +9,11 @@ metadata:
     {{- toYaml . | nindent 4 }}
     {{- end }}
 spec:
-  minAvailable: {{ .Values.nginx.podDisruptionBudget.minAvailable }}
+  {{- if not (kindIs "invalid" .Values.nginx.podDisruptionBudget.maxUnavailable) }}
+  maxUnavailable: {{ .Values.nginx.podDisruptionBudget.maxUnavailable }}
+  {{- else }}
+  minAvailable: {{ .Values.nginx.podDisruptionBudget.minAvailable | default 1 }}
+  {{- end }}
   selector:
     matchLabels:
       {{- include "openops.componentSelectorLabels" (dict "root" . "component" "nginx") | nindent 6 }}

diff --git a/chart/templates/pdb-tables.yaml b/chart/templates/pdb-tables.yaml
@@ -9,7 +9,11 @@ metadata:
     {{- toYaml . | nindent 4 }}
     {{- end }}
 spec:
-  minAvailable: {{ .Values.tables.podDisruptionBudget.minAvailable }}
+  {{- if not (kindIs "invalid" .Values.tables.podDisruptionBudget.maxUnavailable) }}
+  maxUnavailable: {{ .Values.tables.podDisruptionBudget.maxUnavailable }}
+  {{- else }}
+  minAvailable: {{ .Values.tables.podDisruptionBudget.minAvailable | default 1 }}
+  {{- end }}
   selector:
     matchLabels:
       {{- include "openops.componentSelectorLabels" (dict "root" . "component" "tables") | nindent 6 }}

diff --git a/chart/values.yaml b/chart/values.yaml
@@ -193,7 +193,7 @@ app:
   # Pod Disruption Budget - ENABLED BY DEFAULT
   podDisruptionBudget:
     enabled: true
-    minAvailable: 1
+    maxUnavailable: 1
   # Horizontal Pod Autoscaler
   autoscaling:
     enabled: false
@@ -229,7 +229,7 @@ engine:
   # Pod Disruption Budget - ENABLED BY DEFAULT
   podDisruptionBudget:
     enabled: true
-    minAvailable: 1
+    maxUnavailable: 1
   # Horizontal Pod Autoscaler
   autoscaling:
     enabled: false
@@ -269,7 +269,7 @@ tables:
   # Pod Disruption Budget
   podDisruptionBudget:
     enabled: true
-    minAvailable: 1
+    maxUnavailable: 1
   # Horizontal Pod Autoscaler
   autoscaling:
     enabled: false
@@ -332,7 +332,7 @@ analytics:
   # Pod Disruption Budget
   podDisruptionBudget:
     enabled: true
-    minAvailable: 1
+    maxUnavailable: 1
   # Horizontal Pod Autoscaler
   autoscaling:
     enabled: false
@@ -545,7 +545,7 @@ nginx:
   # Pod Disruption Budget - ENABLED BY DEFAULT
   podDisruptionBudget:
     enabled: true
-    minAvailable: 1
+    maxUnavailable: 1
   # Horizontal Pod Autoscaler
   autoscaling:
     enabled: false

diff --git a/docs/DEPLOY_TO_AWS_EKS.md b/docs/DEPLOY_TO_AWS_EKS.md
@@ -751,23 +751,26 @@ nginx:
       # service.beta.kubernetes.io/aws-load-balancer-internal: "true"
 
 # Pod Disruption Budgets for HA
-pdb:
-  enabled: true
-  app:
+app:
+  podDisruptionBudget:
     enabled: true
-    minAvailable: 2
-  engine:
+    maxUnavailable: 1
+engine:
+  podDisruptionBudget:
     enabled: true
-    minAvailable: 2
-  nginx:
+    maxUnavailable: 1
+nginx:
+  podDisruptionBudget:
     enabled: true
-    minAvailable: 1
-  analytics:
+    maxUnavailable: 1
+analytics:
+  podDisruptionBudget:
     enabled: true
-    minAvailable: 1
-  tables:
+    maxUnavailable: 1
+tables:
+  podDisruptionBudget:
     enabled: true
-    minAvailable: 1
+    maxUnavailable: 1
 
 # Horizontal Pod Autoscaling
 hpa: