When draining Istio pods some nodes may not drain because they have a replica count of 1, while 3 or
more replicas are required. In order to avoid this, you should set the minimum replica count for each
property to at least 3.
When backing up and draining Istio nodes you may see errors like:
kubectl drain` failed to evict and reschedule pods to another node due to PodDisruptionBudget definitions:
===
NAMESPACE NAME MIN AVAILABLE MAX UNAVAILABLE ALLOWED DISRUPTIONS AGE
istio-system istio-ingressgateway 1 N/A 2 5d11h
istio-system istio-pilot 1 N/A 2 5d11h
===
Foristio-ingressgatewayandistio-pilotyou can set theistio.ingressgateway.replicaCountMinandistio.pilot.replicaCountMinproperties to3or higher. See theConfiguration properties reference,istio.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003eThe current version of the Apigee hybrid documentation being viewed, version 1.4, is end-of-life and requires an upgrade to a newer version.\u003c/p\u003e\n"],["\u003cp\u003eTo prevent issues with draining Istio pods, ensure that the minimum replica count for each relevant property is set to at least 3.\u003c/p\u003e\n"],["\u003cp\u003eWhen draining Istio nodes, errors may occur due to PodDisruptionBudget definitions, particularly with \u003ccode\u003eistio-ingressgateway\u003c/code\u003e and \u003ccode\u003eistio-pilot\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eSetting the \u003ccode\u003eistio.ingressgateway.replicaCountMin\u003c/code\u003e and \u003ccode\u003eistio.pilot.replicaCountMin\u003c/code\u003e properties to 3 or higher can resolve issues during the draining process.\u003c/p\u003e\n"],["\u003cp\u003eFor Istio components that do not have a replicaCountMin property, refer to the GKE or Istio documentation on how to proceed.\u003c/p\u003e\n"]]],[],null,["# Expand Istio property replica counts to avoid problems when draining Istio nodes\n\n| You are currently viewing version 1.4 of the Apigee hybrid documentation. **This version is end of life.** You should upgrade to a newer version. For more information, see [Supported versions](/apigee/docs/hybrid/supported-platforms#supported-versions).\n\n\nWhen draining Istio pods some nodes may not drain because they have a replica count of 1, while 3 or\nmore replicas are required. In order to avoid this, you should set the minimum replica count for each\nproperty to at least 3.\n\n\nWhen backing up and draining Istio nodes you may see errors like: \n\n```\nkubectl drain` failed to evict and reschedule pods to another node due to PodDisruptionBudget definitions:\n===\nNAMESPACE NAME MIN AVAILABLE MAX UNAVAILABLE ALLOWED DISRUPTIONS AGE\nistio-system istio-ingressgateway 1 N/A 2 5d11h\nistio-system istio-pilot 1 N/A 2 5d11h\n===\n```\n\n\nFor `istio-ingressgateway` and `istio-pilot` you can set the\n`istio.ingressgateway.replicaCountMin` and `istio.pilot.replicaCountMin`\nproperties to **`3`** or higher. See the\n[Configuration properties reference,\n`istio`](/apigee/docs/hybrid/v1.3/config-prop-ref#istio).\n\n\nFor other `istio` components (that don't have a replicaCountMin property), see\n[Manually\nupgrading a cluster or node pool](https://cloud.google.com/kubernetes-engine/docs/how-to/upgrading-a-cluster) in the GKE documentation or\n[IstioOperator\nOptions](https://istio.io/latest/docs/reference/config/istio.operator.v1alpha1/) in the Istio documentation."]]
