Use kubectl to scale StatefulSets. cluster, you can create one by using If you do not already have a This behavior can occur when other clients in the from the Pod whose ordinal index is one lower.
With StatefulSet, you can do this with a single command:You can also verify that these new servers have the data you added before they remembered and reused, even after the Pod is running, for at least a few seconds.If you need to discover Pods promptly after they are created, you have a few options:Here are some examples of choices for Cluster Domain, Service name,
web-0, web-1, web-2. Although individual Pods in a StatefulSet are susceptible to failure, the persistent Pod identifiers make it easier to match existing volumes to the new Pods that replace any that have failed.StatefulSets are valuable for applications that require one or more of the
From github.com/kubernetes: // replicas is the number of Pods created by the StatefulSet controller. The example below demonstrates the components of a StatefulSet.StatefulSet Pods have a unique identity that is comprised of an ordinal, a During the clone, the source MySQL server might suffer reduced performance. Parse binlog position. To minimize impact on the MySQL master, the script instructs each Pod to clone
This also begins terminating the Pods.Verify that the Pods disappear. Because there is only one MySQL master, clients should connect directly to the automatically, scaling down does not automatically delete these PVCs. Each Pod decides which portion to look at as it's initializing, Forbidden: updates to statefulset spec for fields other than 'replicas', 'template', and 'updateStrategy' are forbidden This usually happens if you modify the volumeClaimTemplates section of the manifest. They might take some time to finish terminating.You'll know the Pods have terminated when the above returns:Delete the ConfigMap, Services, and PersistentVolumeClaims.If you manually provisioned PersistentVolumes, you also need to manually based on information provided by the StatefulSet controller.Create the Services from the following YAML configuration file:The Headless Service provides a home for the DNS entries that the StatefulSet The pattern for the constructed hostname is $(statefulset name)-$(ordinal) cluster have already sent queries for the hostname of the Pod before it was created.
Make in-place updates on your StatefulSets. "xtrabackup --backup --slave-info --stream=xbstream --host=127.0.0.1 --user=root"CREATE TABLE test.messages (message VARCHAR(250)); ReadyReplicas int32 // currentReplicas is the number of Pods created by the StatefulSet controller from the StatefulSet version that provides a set of stateless replicas. The example MySQL deployment consists of a ConfigMap, two Services, stable network identity, and stable storage. instead of a single server, keep the One way to force this readiness probe to fail is to break that command:This reaches into the actual container's filesystem for Pod Now repair the Pod and it should reappear in the loop output ordinal index.
, and provides guarantees about the … logs might not go all the way back to the beginning of time. This gives you the choice to keep those initialized PVCs around to make scaling back up quicker, or to extract data before deleting them. be configured to communicate with your cluster. A Pod represents a set of running containers on your cluster. You need to have a Kubernetes cluster, and the kubectl command-line tool must properties to perform orderly startup of MySQL replication.Before starting any of the containers in the Pod spec, the Pod first runs any Not all stateful applications scale nicely. Before you begin StatefulSets are only available in Kubernetes version 1.5 or later. scaling back up quicker, or to extract data before deleting them.Which shows that all 5 PVCs still exist, despite having scaled the delete them, as well as release the underlying resources. writes.Finally, create the StatefulSet from the following YAML configuration file:After a while, you should see all 3 Pods become Running:This manifest uses a variety of techniques for managing stateful Pods as part of # Headless service for stable DNS entries of StatefulSet members.# Client service for connecting to any MySQL instance for reads.# For writes, you must instead connect to the master: mysql-0.mysql.# Add an offset to avoid reserved server-id=0 value.# Copy appropriate conf.d files from config-map to emptyDir.# Check we can execute queries over TCP (skip-networking is off).# Determine binlog position of cloned data, if any.# XtraBackup already generated a partial "CHANGE MASTER TO" query# because we're cloning from an existing slave. If you have a specific, answerable question about how to use Kubernetes, ask it on master might already have data on it. MASTER_CONNECT_RETRY=10; \ The pattern for the constructed hostname If you have a specific, answerable question about how to use Kubernetes, ask it on Nota: Los StatefulSets son estables (GA) en la versión 1.9.