Diferencia entre Statefulset y Deployment en Kubernetes. yaml file. To summarize, the master-slave pod deployment pattern and the concept of state in a StatefulSet are important for managing stateful applications, such as databases, in a distributed system. They guarantee stable and unique network identities, stable and persistent storage, and deployment and. Connect your apps to Copilot. StatefulSets. This can be done by updating the value of an annotation within the pod template. Pods are created and terminated in a predictable order, ensuring orderly scaling and rolling updates. Statefulsets implement this sticky identity in two ways: Predictable Pod Names: Statefulsets have fixed ordered name in the form of: ${statefulset-name}-{ordinal}. Node、Podの障害時の挙動について. Stable And Ordered. g. One of the more powerful features of a StatefulSet is the use of persistent. Here, in this example we are deploying a standalone. Unlike deployments, statefulset maintains an identity for each of the pods. Configuring the YAML for a Deployment StatefulSet vs Deployment. Elaborate more on this if we should never use Deployment. StatefulSet est l'objet de l'API de charge de travail utilisé pour gérer des applications avec état (stateful). StatefulSets. g. yml secret/mysecret created. They both consume resources and can affect overall performance. It allows us to automate deployments, scale, and manage containerized applications. g. Stateful applications are those which required persistent storage to work aptly. Additionally, StatefulSets enables you to reschedule database pods to other nodes. It manages the deployment and scaling of a set of Pods, and provides guarantee about. A DaemonSet ensures that a copy of a particular Pod is running on each node in a cluster or a subset of nodes, and it automatically adds or removes Pods from nodes as. Kubernetes StatefulSets are commonly used to manage stateful applications. Pods (and, by extension, containers) are, nevertheless, short-lived entities. In the case of deployment (Stateless services) the pods are interchangeable because if the pod needs to reschedule it wont maintain the same id as the previous pod. There is also a general lack of understanding when it comes to disk access policies, what RWO/RWX means, and what they allow you to do. StatefulSets in Kubernetes is a workload API that oversees the deployment and scaling of a set of Pods while preserving stickiness to persistent storage and guaranteeing order and uniqueness. 3343 Perimeter Hill Drive. Any application. The example topology has a single primary server and multiple replicas, using asynchronous row-based replication. yaml. Specifying minReadySeconds slows down a rollout of a StatefulSet, when using a. Deployment vs. ) What is Kubernetes StatefulSets? StatefulSet is a Kubernetes workload API object that can be used to manage stateful applications. It allows you to define the Kubernetes Deployment or StatefulSet that you want KEDA to scale based on a scale trigger. It can appear that StatefulSet is a way to solve at most one instance in a situation with a network partition , but that is mostly in case of a stateful replicated application like e. A StatefulSet is better suited to stateful workloads that require persistent storage on each cluster node, such as databases and other identity-sensitive workloads. stateful-set-name. Discover smart, unique perspectives on Statefulsets and the topics that matter most to you like Kubernetes, Deployment, DevOps, K8s, Mongodb, Persistent. yaml We need to create a pvc. StatefulSets are the native Kubernetes resources to manage stateful applications. It demonstrates how to create, delete, scale, and update the Pods of StatefulSets. Roll back a deployment. Apr 6, 2020 at 8:53. They provide stable pod identity, persistent per pod storage and ordered graceful deployment, scaling and rolling updates. Additionally, StatefulSets enables you to reschedule database pods to other nodes. . There seems to be a recurring bad practice among the charts in this repository: using a Deployment to manage pods using Persistent Volume Claims, rather than the proper StatefulSet. Conclusion. StatefulSets is a new feature and, as a result, running this example will require an environment based on Kubernetes 1. kubectl describe svc nginx-app1. This tutorial shows you how to run Apache Cassandra on Kubernetes. The following brings up the StatefulSet including two pods (a leader and a follower), binds the persistent volumes to each pod as well as creates a headless service for it: $ kubectl create ns mehdb. In this article, we will focus on how to deploy a PostgreSQL database on a Kubernetes cluster using StatefulSets. What is Statefulsets? A StatefulSet is a controller that helps you deploy and scale groups of Kubernetes pods. Step 1. My problem is that if I'm writing into Solr during a rolling update of the statefulset I get errors when I reach the deployment of the solr cluster leader. Watch the presentation below given by Ali Kahoot, DevOps Engineer & Trainer at Tarabut Gateway. 1. StatefulSets and PDBs. For an even more than basic primer on StatefulSets, visit the Kubernetes documentation here. 那使用Deployments更重要的是，可以方便Rollback到之前版本，而使用StatefulSets、DaemonSets. Before you begin StatefulSets are only available in Kubernetes version 1. Contrairement à un Deployment, un. 2. Let's be friends: Explore managing stateful applications with Kubernetes StatefulSets — when to use them, how to deploy MongoDB. Deploy The Stack. Although Kubernetes is best known for running applications, it's also capable of running databases. It is clearly explained in the documentation under Deleting the Statefulset: Deleting a StatefulSet through kubectl will scale it down to 0, thereby deleting all pods that are a part of it. This is great for stateless apps that we want online, ASAP. e. Deployment vs. ReplicaSet ReplicaSet 的目的是维护指定数量的 Pod，常用做保障指定数量 Pod 的可用性 Deployment Deployment 是一个用来管理 ReplicaSet 的更高级概念，某种程度上我们不应该操作 ReplicaSet，而是直接使用 Deployment。Deployment 拥有 Rollout & Rollback 功能，方便我们管理。 StatefulSet StatefulSet 用来管理有状态的应用，其会. StatefulSets:Initially deployment should come up with 1 replicas when 1st node is created and grow as we add more worker/master nodes to it and once max is achieved, it should stop growing. In a few minutes, there will be 5 MongoDB pods. I think statefulsets make sense for it. StatefulSets provide the ability to use persistent volumes for each. To check your version of Kubernetes, run kubectl version. Whereas the Statefulsets maintain a unique. statefulSet {. Ordering: Kubernetes StatefulSets ensure that each pod is created in a specific order, while Deployments do not. id-0, id-1, id-2 and so on) for each of their Pods. 0. 4 Creating a Service for the StatefulSet; 8. Manages the deployment and scaling of a set of Pods, and provides guarantees about the ordering and uniqueness of these Pods. As a reminder, our goal (for now) is for each instance of a MongoDB to get a separate volume. Similarly, the deployment script. When you have an app which requires persistence, you should create a stateful set instead of deployment. When using Kubernetes, most of the time you don’t care how your pods are scheduled, but sometimes you care that pods are. yaml. These priorities does not only happens when a Node becomes unreachable, but at all times, e. It is roughly analogous to a Deployment, but tailored to stateful rather than stateless processes. Deployments, StatefulSets, and DaemonSets allow you to scale up your Pods, roll out new images and configurations, and more. Deploy the Java service to Amazon EKS. When comparing a Deployment vs Replica Set, the former provides the same replication functions (through Replica Sets) and also the ability to rollout changes and roll them back if necessary. 0 with new features and enhancements is available now. A StatefulSets are Kubernetes objects used to consistently deploy stateful application components. Both are related to the limited control that deployments provide over how an application runs: Lack of granular control. StatefulSets - A StatefulSet is similar to a deployment in that one or more identical pods are created and managed. Statefulsets are used for databases where the state of the application is the crucial part of the deployment. This article describes how to create, update, and delete StatefulSets, which are used to maintain the state of an application beyond a pod lifecycle in an Azure Kubernetes Serice deployment in AKS hybrid. I'll try removing some parts of the alertmanager deployment to identify the issue. イメージ的にはPodTemplateを持つDeploymentにPVCも追加した感じ。. 9) is a Kubernetes resource used to manage stateful applications. yaml) and deploy them with kubectl apply -f <stateful-set-name>. DaemonSets. MySQL, PostgreSQL, Redis, Elasticsearch) onto Kubernetes. Cada una con sus características, ventajas y desventajas. 22. StatefulSets are valuable for the applications that require one or more of the following, Stable, unique network identities. Kubernetes Tutorial for Beginners. Does it need ordered instance scale-up and scale-down? If you share what application you are using, it is easier to tell if it tolerate that the instances scale-up or. StatefulSets are valuable for applications that require one or more of the following. Deployment Vs Stateful sets. Workload Resources StatefulSets StatefulSets StatefulSet is the workload API object used to manage stateful applications. Deployments mount a single persistent volume no matter the number of replicas: 10 pods of the same deploy will try to mount the same volume for both read and write operations. In the previous blog we created a stateless application, deployed with K8s resource Deployment, which allows one to replicate the application, but where data is lost when Pods are restarted, meaning there were no data consistency. To help deploy Pods, Kubernetes provides three different options: Deployments, DaemonSets, and StatefulSets. StatefulSets are useful for stateful applications, which require a stable pod name. So by passing this flag to kubectl delete the Pods that are managed by. A big advantage of Kubernetes and StatefulSets is that you can scale the number of MongoDB Replicas up and down with a single command! To scale up the number of replica set members from 3 to 5, run this command: kubectl scale --replicas=5 statefulset mongo. #72. If you want to provide workload persistence using Kubernetes persistent storage, you can incorporate a StatefulSet into your solution. What is the difference between StatefulSet and Deployment? Ans: A StatefulSet acts as a controller in Kubernetes that manages pods just like Deployments. Ordered, graceful deployment and. Today, we’ll take a look at some of the same YAML markup, but zero in on StatefulSets instead. Deploying a MongoDB Database: Here is an example of how to deploy a MongoDB database using a StatefulSet in Kubernetes. It dictates the needs of dedicated volumes, unique hostname records, and a specific order of deployment. Deployment; StatefulSets; DaemonSets “Hay otro, el ReplicationController pero Kubernetes ahora apunta a Deployment que automáticamente crea ReplicaSets. StatefulSets are designed to run stateful applications in Kubernetes with dedicated persistent storage. What then is the advantage of using StatefulSets?而因為有關聯，所以在Deployment下的Label Name，會同樣印在pod上。. This is a simple example of the above one. Gère le déploiement et la mise à l'échelle d'un ensemble de Pods, et fournit des garanties sur l'ordre et l'unicité de ces Pods. io. When deployed with only 1 replica, the differences with a Deployment are small (but there are differences, for example a Deployment's Pod would eventually restart on another node if the node on which it was running stops working, a StatefulSet Pod will require manual intervention). By far the most common way to run a database, StatefulSets is a feature fully supported as of the Kubernetes 1. yaml>. Kubernetes Deployments Vs StatefulSets. Nota: Los StatefulSets son estables (GA) en la versión 1. com. StatefulSetではPodのSTATUSがUnknownになってもPodを自動起動しない。Kubernetes StatefulSets. you can do that by entering the following command: touch example-statefulset. Very useful for HA workloads. The simple scalable deployment mode, is the preferred way to deploy Loki for most installations. Deployment vs Statefulset . We'll use Jenkins as the first application we'll deploy. This is the expected behavior. Deployment. There is confusion amongst Kubernetes users as to when one should make a Deployment with a PVC and when they should use a StatefulSet with a PVC. StatefulSets can be used to create pods with a guaranteed start-up order and unique identifiers. When the Grafana deployment becomes unstable due to crash looping, bugs, and so on, you can roll back a deployment to an earlier version (a REVISION). StatefulSet Kubernetes | Understand what StatefulSet in Kubernetes is and how it works Using StatefulSet in practice 🙅🏼♀️ youtu. They let you ensure that pods are scheduled in a specific order, that they have persistent storage volumes. But Statefulsets eliminates the previous states and data stored problems. It worked as expected and both the prometheus pods got restarted. Ordered Deployment and Scaling. Elaborate more on this if we should never use Deployment. 1. This allows you to easily replicate Pods and attach a storage volume to the Pods. Note: While ReplicaSets can be used, Kubernetes recommends using Deployments. In this article. In this. 🤝 - LinkedIn - - Threads - - Twitter - (K8s) is an open-source container orchestration system which provides deployments, statefulsets & daemonsets to deploy… 8 min read · Apr 18, 2019 12I want to give my application limited access to get the replicas of different statefulsets (and maybe deployment) and if necessary scale them up or down. statefulset "mariadb" deleted. This tutorial will demonstrate Kubernetes StatefulSets as well as PodDisruptionBudgets, and PodAntiAffinity. StatefulSets. yaml file first, so that even if our pod restarts or gets deleted, our data won. Kubernetes DaemonSet is a great way to manage and deploy applications in a clustered environment. Before we start discussing the details of this definition, notice that the file actually contains two definitions: the storage class that the StatefulSet is using and the. yaml. This comes at a cost of slow scale ups and. Stateful and Stateless Applications. Let's see a StatefulSet in action and see whether it beings any benefits. OF THE TALKKubernetes provides different resources for deploying applications, we will be lookin. This label ensures that child ReplicaSets of a Deployment do not overlap. 25. This binded volume is claiming ressources through the persistent volume claim. This sub-command will stop the current rollout and start a new one, using the current configuration settings. StatefulSet is the workload API object used to manage stateful applications. For mysql i am using statefulset and the code is here: apiVersion: apps/v1 kind:Author: Matthew Cary (Google) Kubernetes v1. js application and you want to scale the Node. The kubectl apply -f used to apply the configuration file kubernetes (where your deploy your desired application). StatefulSets are valuable for applications that require one or more of the following. Una aplicación stateless es aquella que no tiene estado, a la que no le importa la red en la que se esta. You can only delete or scale up/down the Statefulset. Statefulsets is used for Stateful. The StatefulSet controller uses this field as a collision avoidance mechanism when it needs to create the name for the newest ControllerRevision. When to use StatefulSets. This tutorial provides an introduction to managing applications with StatefulSets. Define a Stateful Set with PVC. StatefulSet vs. The deployment is made up of 2 Nginx web servers; both of them are connected to a persistent volume. Then you will be able to set ingress and use it to redirect traffic based on path:. The simplest method to expose your services is to use a NodePort , in which case your service will take on the IP of the node externally with a high port number (30000+). I am using local storage and I dont want statefulsets getting scheduled in a single node. service都有ClusterIP,可以负载均衡 StatefulSet适合场景有状态的应用特点1. When comparing a Deployment vs Replica Set, the former provides the same replication functions (through Replica Sets) and also the ability to rollout changes and roll them back if necessary. After kubernetes 1. Nashville, TN 37211. Deployments vs Statefulsets. 1 Answer. This page describes the use of StatefulSet objects in Google Kubernetes Engine (GKE). The output of the describe command in this example is the following: Name: nginx-app1. 所有pod共享存储 3. You may need to delete the associated headless service separately after the StatefulSet. Deployments use ReplicaSets as a mechanism to orchestrate Pod creation, deletion, and updates. This sticky characteristic makes it possible to run databases on. I didn't really talk about (3) and (4) but that can also help with clusters as you can tell the first one to deploy to become the master and the next one find the first and treat it as master, etc. yaml. system (system) Closed March 11, 2022, 6:44am 3. The following picture explains how scale down and scale up will happen in StatefulSets. If a new deployment or statefulset tries to lay claim to a volume claim with the same name as an existing deployment or statefulset, then the new pod(s) will become stuck as unscheduleable. Pods in a StatefulSet will have an IP. Find a wide-ranging variety of Deployment Vs Statefulset In Kubernetes Statefulset In Kubernetes Explained Stateless Stateful classified ads on our high-quality marketplace. They let you ensure that pods are scheduled in a specific order, that they have persistent storage volumes available, and that they have a persistent network ID that is maintained even when a pod shuts down or is rescheduled. Deployments have two main disadvantages compared with StatefulSets and DaemonSets. Pods use a persistent volume claim as a request for storage that is matched to a persistent volume by the Kubernetes cluster. Pods deployed by Deployment are identical and interchangeable, created in random order with random hashes in their Pod names. 4. 4. It is generated by hashing the PodTemplate of the ReplicaSet and using the resulting hash as the label value that is. They let you ensure that pods are scheduled in a specific order, that they have persistent storage volumes available, and that they have a persistent network ID that is maintained even when a pod shuts down or is rescheduled. In the last lesson, we skipped over the whys and wherefores of StatefulSets to focus on implementing Secrets. 5 and becoming stable in 1. 3 ReplicaSet, Deployment, StatefulSet Controllers. In Kubernetes, a Deployment is a workload resource object that lets you configure the lifecycle of pods in the cluster. persistent deployment manifest: As you can see its straight forward. We will use the gce-pd storage to store the data. Headless Services: For stateful applications, use headless services to create stable network identities for each pod. The StatefulSet will not create all the pods at once, like a Deployment, for example. StatefulSets maintain the state of applications beyond an individual pod lifecycle. We can use the kubectl describe secret command to display additional information about the resource. 3 Updating a StatefulSet. You can use DaemonSet to run a cluster storage, log collection, and node monitoring demon on each node. Normally a pod would get a new name if it is killed and respawned by Kubernetes, but if it is managed by a Statefulset it respawns with the same name. Para entender por qué aplicar un objeto de tipo Statefulset en lugar de Deployment, antes de nada necesitamos conocer las diferencias básicas entre Stateless y Stateful. podManagementPolicy: "Parallel". In statefulset pod`s names are in sequential order on the other hand in. StatefulSets are created in a similar way to Deployment objects. This article contains best practices and guidance for running SQL Server containers on Kubernetes with StatefulSets. 1. As the name suggest the statefulsets are specifically used to make sure the app state is saved by each running pod. StatefulSets handle the deployment and scaling of sets of Kubernetes pods, providing guarantees about their uniqueness and ordering. Deployment is a resource to deploy a stateless application, if using a PVC, all replicas will be using the same Volume and none of it will have its own state. (This article is part of our Kubernetes Guide. Fully managed. StatefulSet is also a Controller but unlike Deployments, it doesn’t create ReplicaSet rather itself. StatefulSets: Orchestrating Stateful Applications. The most basic difference is that you would get ability to persist pod level state with statefulsets. Here you can see how the Deployment itself runs a ReplicaSet that then runs 3 pods. You would often use Statefulset if you want your. You can delete a StatefulSet in the same way you delete other resources in Kubernetes: use the kubectl delete command, and specify the StatefulSet either by file or by name. It is similar to Deployment, but Statefulsets requires a Service Name . Not something I thought of a couple a years ago when the chart was made. and data from the image is copied to only one PVC where are rest two pods. No guarantee of unique network identities or persistent storage. Thus, you have one SQL Server instance deployed per pod in the Kubernetes cluster. StatefulSets are intended to be used with stateful applications and distributed systems. They each have their own sticky identity, which they keep between. Create Some Data. Unlike in a standard Deployment, StatefulSets are aware that your application is stateful and will therefore treat it accordingly. You can also create Pods (containers) using the Deployment object in the Kubernetes cluster. DaemonSets. You should not run a database (or other stateful workload) as Deployment, use StatefulSet for those. Example. Statefulsets only provide a way to have unique naming e. It makes sense also as each Redis instance relies on a configuration file that keeps track of other cluster instances and their roles. Additional note: PVCs created by StatefulSets won't be deleted when deleting the StatefulSet as resource. Configuring the YAML for a DeploymentStatefulSet vs Deployment. In practice, StatefulSets are most commonly used to deploy databases (e. Deployment Spec vs StatefulSet Spec Deployment specs and StatefulSet specs are quite similar. A StatefulSet is better suited to stateful workloads that require persistent storage on each cluster node, such as databases and other identity-sensitive workloads. Understanding ReplicaSet vs. 5. If ordering may become important in the future, statefulsets become the obvious route; you can replicate deployment behavior with statefulsets, but not (as easily) in the other direction. When you update the Pod template in a StatefulSet, the controller recreates the Pods with the updated template. You could set spec. Stable Network Identities: StatefulSets provide stable network identities for each pod, making it easy to communicate with specific pods in the set. In summary, StatefulSets are great building blocks for running stateful workloads on Kubernetes. 申请转载. What is the difference between Deployment and StatefulSet components? 🤔 Deployment vs StatefulSet component Pods deployed by Deployment are identical and. Stable, persistent storage. To update the deployment, modify the YAML file and run the same command again. This allows Pods to maintain individual state that's separate from their neighbors in the set. apiVersion: v1 kind: Secret metadata: name: mysecret type: Opaque data: ROOT_PASSWORD: cGFzc3dvcmQ=. This allows you to easily replicate Pods and attach a storage volume to the Pods. StatefulSets and DaemonSets. StatefulSets. StatefulSets go a long way in reducing the complexity of deploying and managing stateful applications in Kubernetes. e. In this video, we cover Kubernetes Statefulsets in detail. The primary idea behind StatefulSets is to allow developers to deploy applications that require data to be stored in a filesystem with the ability to re-attach to them if they restart by failure. Deployment. Stable, unique network identifiers. Examples include databases like MySQL, PostgreSQL, and Redis, HTTP servers like NGINX and Apache, and persistent brokers like Kafka and Zookeeper. StatefulSet. They differ in terms of maintaining a persistent identity for each pod. Here are some main differences between Deployments and StatefulSets: Deployments are used for stateless applications whereas StatefulSets for stateful applications. This service will need to be created with: selector: statefulset. Statefulsets are used for databases where the state of the application is the crucial part of the deployment. More info about statefulsets. “Hay otro, el ReplicationController pero Kubernetes ahora apunta a Deployment que automáticamente crea ReplicaSets”. 80 383 more pod1. Because we specify all of our Prometheus and Kubernetes YAML with Jsonnet, we can do some nice things to keep both StatefulSets consistent in the future. Key differences. It’s easy to use and has a wide range of features, making it an ideal choice for managing applications in a production environment. currently we scaled one of our statefulsets to have 11 replicas. We need to specify service instances to be deployed to different boxes, anti-affinity on pods, for high availability. A StatefulSet is a controller that helps you deploy and scale groups of Kubernetes pods. g. For example stateful set can be useful for Elasticsearch, Redis. Today, we’ll take a look at some of the same YAML markup, but zero in on StatefulSets instead. a cache or database cluster even though it may solve your specific situation as. Kubernetes StatefulSets are used to deploy stateful applications inside your cluster. S tatefulSet represents a set of Pods with unique, persistent identities and stable hostnames. 𝐉𝐨𝐢𝐧 𝐭𝐡𝐞 𝐅𝐫𝐞𝐞 𝐌𝐚𝐬𝐭𝐞𝐫𝐜𝐥𝐚𝐬𝐬 𝐨𝐧 𝐃𝐨𝐜𝐤𝐞𝐫 & 𝐊𝐮𝐛𝐞𝐫𝐧𝐞𝐭𝐞𝐬 𝐅𝐨𝐫. In a production environment it is better to use a declarative operation, e. you can do that by entering the following command: touch example-statefulset. In statefulsets each replica pod created has an index number starting from 0 and it will only setup the next replica if the previous one is running. Otherwise, using StatefulSets will help ensure a number of requirements can be met for your stateful app. All the examples available are showing Redis cluster being deployed as a combination of Kubernetes’ StatefulSets and PersistentVolumes. Figure-3 captures the state of the Kubernetes cluster. In Kubernetes, a Deployment is a workload resource object that lets you configure the lifecycle of pods in the cluster. updateStrategy is left unspecified. The Deployment controller handles the disposing of pods if they become unhealthy or are no longer needed. Side note, you may consider deploying your SQL using Helm because someone else has already solved many of these issues using a chart so you don't have to. KEDA will monitor that service and based on the events that occur it will automatically scale. The volumeClaimTemplates automatically creates a new PersistentVolumeClaim each time a pod is replicated. Stable unique network identifiers. 2. Stable, persistent storage. full vs. Overall, StatefulSets are a valuable resource in Kubernetes that can help you manage stateful applications with confidence and predictability. TL;DR. Stable (persistent), unique network identifiers. Amazon DocumentDB (with MongoDB compatibility) is a scalable, highly durable, and fully managed database service for operating mission-critical MongoDB-compatible JSON based workloads. 7 StatefulSet vs Deployment: associated serviceIt watches changes in ConfigMap and Secrets and then updates Deployment, StatefulSet and DaemonSet, so that the new changes are loaded. Coordinators, brokers, and routers are stateless in nature, thus deployments make more sense and avoid complexities to manage statefulsets. If your application is stateless, you should use Deployment and not StatefulSet. You can think of StatefulSet as the. be/JGtJj_nAA2s Kubernetes Operator explained (manager for your stateful application 🚀) youtu. com. You can see that with the kubectl get deploy and kubectl get statefulset> commands, both are ready. The example in this blog deploys on Centos7 using kubeadm. Kubernetes (K8s) is an open-source container orchestration system. Deployment is a resource to deploy a stateless application, if using a PVC, all replicas will be using the same Volume and none of it will have its own state. DaemonSets replicate a Pod to every Node in your cluster, while StatefulSets provide persistent replica identities. Published Oct 5, 2022 StatefulSets let you run stateful applications in Kubernetes. 1 Answer. When you’re deploying an application in Kubernetes, you have a few options to choose from. As opposed to the Deployment, the StatefulSet creates pods directly. The StatefulSet will not. After successfully starting kube-apiserver and kube-controller-manager, you will see AvailableReplicas in the status and minReadySeconds. As of Kubernetes v1. Their purpose is to keep a set of identical pods running and upgrade them in a controlled way. To provision a static PV for a Deployment workload, the procedure is as follows: Note: The examples in this section. 9 release. I have a kubernetes cluster and I have a simple deployment for mongodb with NFS persistent volume set. Deployment. In our case it will be a MariaDB container configured as statefulset set, in stead of a deployment. $ kubectl apply -f secret. StatefulSets. Just to avoid data corruption if you are changing the replica to more then one.