consul VS Apache ZooKeeper

The JHipster scaffolded sample application has a gateway application and two microservices. It uses Consul for service discovery and centralized configuration.

Service Discovery: Microservices need to discover and communicate with each other dynamically. Service discovery tools like etcd, Consul, or Kubernetes built-in service discovery mechanisms help locate and connect to microservices running on different nodes within the infrastructure.

After some research and testing, I landed on using Consul and Fabio as the demo infrastructure. Of course, there is a myriad of other options to accomplish this task, but because of the low configuration and ease of use, I was impressed with this pairing. Both projects are mature and well-supported, and very flexible--just because you can run them with low configuration, doesn't mean you have to. I wanted to keep this demo constrained, but the exercise did get me excited about exploring things further: circuit breakers, traffic splitting, and more complex service meshes.

The goal is to be able to use Consul SD configurations to allow for retrieving scrape targets from consul. Is this possible? Can anyone provide an example? Thank you!!

https://github.com/hashicorp/consul/pull/12080 - this should be the Consul issue that brought down Roblox

The Consul collector is production ready! Consul by HashiCorp is a powerful and complex identity-based networking solution, which is not trivial to monitor. We were lucky to have the assistance of HashiCorp itself in this endeavor, which resulted in a monitoring solution of exceptional quality. Look for common blog posts and announcements in the coming weeks!

Changed the service discovery to Consul, since this is the default in JHipster 8.

In another effort to standardize development and operations, Lob has just wrapped up our container orchestration migration from Convox to HashiCorp’s Nomad, led by Senior Platform Engineer Elijah Voigt. In this new ecosystem, one feature available to us is Consul Service Mesh (a feature of Consul, which is part of our Lob Nomad stack).

Service registry and discovery etcd, consul, nacos

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.