Apache ZooKeeper VS consul-template

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

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.

The Hashicorp corporation has made a huge impact in providing valuable tools and platforms in the cloud ecosystem. The advantage of using the tools they provide, such as Terraform, Vault, and Packer, is that they all have the same language, Hashicorp Configuration Language (HCL). This means you can easily pick up any of these tools by learning HCL, which is similar to JSON. This approach can be useful when choosing tools to learn or use for a project.

Terraform is an open-source infrastructure as a code tool. It is designed by HashiCorp and written in Go Programming Language. Terraform is used to automate the creation of DevOps infrastructure and tasks. Terraform provisions and configures your DevOps infrastructure. It spins up new servers, creates load balancers, and node groups, and performs network configurations. Terraform is mostly applied to provision resources on cloud providers like AWS, Google Cloud, and Microsoft Azure. It can automate and provision infrastructure on any cloud platform. We will use Terraform to set up an Azure Kubernetes Service Cluster that has all the necessary cloud resources.

It can be time-consuming to create and manage the infrastructure that drives your software applications as they grow and become larger. Also, what about ongoing updates and releases of new features? Luckily, there is a solution to this problem in the form of a tool designed by Hashicorp called Terraform. This allows us to define our infrastructure in a central configuration file without having to create it on every provider platform we use.

HashiCorp Sentinel: Sentinel is a PAC tool developed by HashiCorp that can be used in tools such as Terraform, Vault, and Nomad. Sentinel supports writing rules in programming languages such as HCL to automate the enforcement of security and compliance policies.

It was clear back in 2021 that Lob needed to consolidate how we run code and none of our current tools were up to the task; it wasn’t a matter of if Lob would upgrade to something new, but when. The Platform team kicked off a research project to find Lob’s next service platform. Forever ago (back in 2019) we investigated migrating to Kubernetes, a popular but notoriously difficult-to-manage tool for this sort of thing, but that project fizzled out for many reasons, forcing us to consider something else. We chose Nomad which offers a comparable feature set to Kubernetes in a much more streamlined package. Nomad is developed by HashiCorp, a leader in the DevOps space, and is used by companies like Pandora, Cloudflare, Internet Archive, and Roblox.

Building upon this, Hashicorp developed consul-template, which is essentially cloud native change configuration, and Consul Connect, now called Consul Service Mesh, which can automatically inject side-car proxy containers into your network, so that services can communicate securely.

If however, you have an application service that needs support for 2+ ports, because you know, Kubernetes supports this, I would recommend avoiding Consul Connect, as it is not functional to meet minimum requirements for a service mesh. Perhaps someday, when Hashicorp prioritizes basic functionality and usability in future version, this product can be considered.

AWS VPC is a simple example. This feature really shines when building reusable infrastructure-as-code for Network Firewall or even Network ACLs. Anything that simplifies something and reduces or eliminates any hacks required to reach a logical outcome is super valuable. Great work finally driving this one home HashiCorp.

Terraform is a cross-platform infrastructure-as-code tool from HashiCorp. The core product is an open-source command-line interface (CL) tool, however, the company also provides enterprise and cloud-based offerings that add additional functionality.