Apache ZooKeeper VS kubernetes

zookeeper: is (was?) used for secrets management. it was also used as a basic health check, but has been since been replaced.

You can install Kafka from https://kafka.apache.org/quickstart. Because Druid and Kafka both use Apache Zookeeper, I opted to use the Zookeeper deployment that comes with Druid, so didn’t start it with Kafka. Once running, I created two topics for me to post the data into, and for Druid to ingest from:

Please note that we use Zookeeper as the Governance Center.

Next, review deployment complexity such as DB-less versus database-backed deployments. For example, Kong does require running Cassandra or Postgres. Apigee requires Cassandra, Zookeeper, and Postgres to run, while other solutions like Express Gateway and Tyk only require Redis. Apache APISIX uses etcd as its data store, it stores and manages routing-related and plugin-related configurations in etcd in the Data Plane.

ZooKeeper, a system for coordinating distributed nodes, similar to Google's Chubby

ElasticJob achieves distributed coordination through ZooKeeper. In practical scenarios, users may start multiple jobs in the same project simultaneously, all of which use the same Apache Curator client. There are certain risks due to the nature of ZooKeeper and the callback method of Curator in a single event thread.

For now we just need to know that Kafka will be running n brokers acting as a cluster. The Kafka cluster will use Zookeeper to orchestrate the brokers.

We spin up a Zookeeper instance at port 2181 internally within the Docker network (i.e. not accessible from the host)

To solve this issue we can use a distributed system manager such as Zookeeper which can provide distributed synchronization. Zookeeper can maintain multiple ranges for our servers.

So now I'm thinking ill have to do something similar to this, https://github.com/kubernetes/kubernetes/issues/57923, where I use an init container to copy the configmaps files, to another volume that I mount on the ActiveMQ container, and before launching activemq, Ill need to copy those files into place.

apiVersion: extensions/v1beta1kind: Deploymentmetadata: name: kube-dns namespace: kube-system labels: k8s-app: kube-dns kubernetes.io/cluster-service: "true"spec: strategy: rollingUpdate: maxSurge: 10% maxUnavailable: 0 selector: matchLabels: k8s-app: kube-dns template: metadata: labels: k8s-app: kube-dns annotations: scheduler.alpha.kubernetes.io/critical-pod: '' scheduler.alpha.kubernetes.io/tolerations: '[{"key":"CriticalAddonsOnly", "operator":"Exists"}]' spec: containers: - name: kubedns image: gcr.io/google\_containers/kubedns-amd64:1.9 resources: limits: memory: 170Mi requests: cpu: 100m memory: 70Mi livenessProbe: httpGet: path: /healthz-kubedns port: 8080 scheme: HTTP initialDelaySeconds: 60 timeoutSeconds: 5 successThreshold: 1 failureThreshold: 5 readinessProbe: httpGet: path: /readiness port: 8081 scheme: HTTP initialDelaySeconds: 3 timeoutSeconds: 5 args: - --domain=cluster.local. - --dns-port=10053 - --config-map=kube-dns # This should be set to v=2 only after the new image (cut from 1.5) has # been released, otherwise we will flood the logs. - --v=2 env: - name: PROMETHEUS\_PORT value: "10055" ports: - containerPort: 10053 name: dns-local protocol: UDP - containerPort: 10053 name: dns-tcp-local protocol: TCP - containerPort: 10055 name: metrics protocol: TCP - name: dnsmasq image: gcr.io/google\_containers/kube-dnsmasq-amd64:1.4.1 livenessProbe: httpGet: path: /healthz-dnsmasq port: 8080 scheme: HTTP initialDelaySeconds: 60 timeoutSeconds: 5 successThreshold: 1 failureThreshold: 5 args: - --cache-size=1000 - --no-resolv - --server=127.0.0.1#10053 - --log-facility=- ports: - containerPort: 53 name: dns protocol: UDP - containerPort: 53 name: dns-tcp protocol: TCP # see: https://github.com/kubernetes/kubernetes/issues/29055 for details resources: requests: cpu: 150m memory: 10Mi - name: dnsmasq-metrics image: gcr.io/google\_containers/dnsmasq-metrics-amd64:1.0.1 livenessProbe: httpGet: path: /metrics port: 10054 scheme: HTTP initialDelaySeconds: 60 timeoutSeconds: 5 successThreshold: 1 failureThreshold: 5 args: - --v=2 - --logtostderr ports: - containerPort: 10054 name: metrics protocol: TCP resources: requests: memory: 10Mi - name: healthz image: gcr.io/google\_containers/exechealthz-amd64:v1.2.0 resources: limits: memory: 50Mi requests: cpu: 10m memory: 50Mi args: - --cmd=nslookup kubernetes.default.svc.cluster.local 127.0.0.1 >/dev/null - --url=/healthz-dnsmasq - --cmd=nslookup kubernetes.default.svc.cluster.local 127.0.0.1:10053 >/dev/null - --url=/healthz-kubedns - --port=8080 - --quiet ports: - containerPort: 8080 protocol: TCP dnsPolicy: Default and this is my kube-dns-svc.yaml:

They've had since December 2020 to update their cluster, and the breaking-ness in 1.24 is called out in a section titled 'Urgent Update Notes'[0], and subtitled 'No, really, you MUST read this before you upgrade'.

So by 'word police' you mean 'admins who didn't bother to read the release notes for the last two years and just deployed straight to production while ignoring the release notes'.

Whatever your politics, breaking changes happen. Not reading the release notes and checking to see if anything affects you is just incompetence.

[0] https://github.com/kubernetes/kubernetes/blob/master/CHANGEL...

On the bright side, it looks like this might happen eventually if Kubernetes support is ever implemented in act_runner. See act_runner issue #19 and act_runner issue #31.

I heard here it may be https://github.com/kubernetes/kubernetes/blob/master/cluster/kube-push.sh. If that is the case how does kube-push.sh relate to https://github.com/GoogleCloudPlatform/kubernetes/blob/master/cluster/gce/upgrade.sh?

Use a container orchestration platform: Use a container orchestration platform such as Kubernetes to manage your infrastructure. Kubernetes provides a range of security features that can be used to secure your applications, infrastructure and manage the traffic to your containerized environment securely using Ingress Controller.

You absolutely can write very high performance software in Go, that's kind of the point. You can efficiently interface with C libraries. You can create the sort of software everyone says should be done in Rust, like databases and web servers and system orchestration and games and every other goddamn thing that people will say isn't the right choice for Go.

If you're comfortable with Kubernetes, you can also deploy Hasura to a Kubernetes cluster. Hasura provides official Helm charts and Kubernetes manifests for deploying your application to Kubernetes.

Of course if you want to learn it and what you can do with it then you need to do the work and start with the documentation at https://kubernetes.io and probably read a book or two. There are also lots of Youtube videos, I seem to remember TechWorld with Nana being pretty good.

Kubernetes is an open-source platform that is used for the automation and management of containerized software applications. It allows developers to deploy applications on multiple servers without worrying about the underlying infrastructure. It is owned by Google and was created in 2014 with the aim of managing cloud applications. It is currently maintained by the Cloud Native Computing Foundation (CNCF). Cloud platforms are various providers with both the hardware and operating system of web-based data centers. These cloud platforms are of different types and range from private servers to public cloud platforms, which are third-party providers. Examples of public cloud platforms are AWS, GCP, Microsoft Azure, and Digital Ocean.