Juju VS Apache ZooKeeper

Basically juju is used to deploy microservices, and other stuff too: https://juju.is/

Juju https://juju.is/

https://juju.is/

Each app is packaged in a charm which seems to be a yaml declaring inputs, dependencies and other meta data and optional python code that can respond to certain lifecycle hooks

https://discourse.charmhub.io/t/implementing-relations/1051

   name: my-node-app

I am currently working myself through setting up our new Research GPU-Cluster where we have "sort of" managed to deploy MAAS to manage all the servers more efficiently, and on top of MAAS then use Juju to deploy the further components of the cluster. The components here are

Kubernetes Custom Resources were created to allow the Kubernetes API to be extended for domain-specific logic, by defining new resource types and controllers. OSS frameworks like operator-sdk, kubebuilder and juju were created to simplify the creation of custom resources and their controllers. Tools built with these frameworks came to be known as Operators.

Depending on what you're trying to accomplish, Juju and MAAS, if not just automate with preseed for custom desktops.

At Canonical I work on two open-source projects written in Go: Juju, a large cloud-based application deployment tool, and Pebble, a small Linux service manager. Both include CLI clients and API-based server daemons. Juju in particular is a large distributed system.

The new Portainer charm allows users of Canonical’s Charmed Kubernetes distribution to automatically install and integrate Portainer Business as part of the Kubernetes cluster deployment process, using Juju, the Charmed Operator framework.

Apache ZooKeeper — a distributed coordination, synchronization, and configuration service (written in Java);

To use Kafka, we also need to deploy a service that keeps configuration informations such as Zookeeper.

Failure Detection and Recovery It’s not enough to have backup systems. It’s also crucial to detect failures quickly. Modern systems employ monitoring tools and rely on distributed coordination systems such as Zookeeper or etcd to identify faults in real-time: once detected, recovery mechanisms are triggered to restore the service.

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

[Unit] Description=Apache Zookeeper server Documentation=http://zookeeper.apache.org Requires=network.target remote-fs.target After=network.target remote-fs.target [Service] Type=simple ExecStart=/usr/local/kafka/bin/zookeeper-server-start.sh /usr/local/kafka/config/zookeeper.properties ExecStop=/usr/local/kafka/bin/zookeeper-server-stop.sh Restart=on-abnormal [Install] WantedBy=multi-user.target

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.