Consul Tutoriallearning manual
Published on 2023-04-20 00:10:05 · 中文 · بالعربية · Español · हिंदीName · 日本語 · Русский язык · 中文繁體
Consul is an important service discovery tool in the Devops world. This tutorial covers in-depth working knowledge of Consul and its setup and deployment. This tutorial aims to help new users set up consultations, develop advanced knowledge of consultations, and learn some interesting projects built around consultations. Finally, we hope that readers can understand this tutorial and use consult in their daily work. This tutorial will provide you with a quick start to Consul and familiarize you with its various components.
Consul is a Hashicorp based tool for discovering and configuring various services in your infrastructure. It is based on and built on Golang. One of the core reasons for building Consul is to maintain the services that exist in distributed systems. Consul provides some important features as follows.
Service Discovery- Using DNS or HTTP, applications can easily find the services they rely on.
Health check status- It can provide any number of health checks. Service discovery components use it to route traffic away from poorly performing hosts.
Key/Value Storage- It can use Consul's hierarchical key/value storage for any purpose, including dynamic configuration, functional tagging, coordination, leadership elections, etc.
Multi data center deployment- Consul supports multiple data centers. It is used to build additional abstraction layers to extend to multiple regions.
Web UI- Consul provides its users with a beautiful web interface that makes it easy to use and manage all the functions in Consul.
Service Discovery
Service discovery is one of Consul's most important features. It is defined as the network protocol used to detect different services and discover services. The use of service discovery has brought good news to distributed systems. This is one of the main issues facing large industries today, as distributed systems progress in their environments.
Comparison with Etcd and Zookeeper
When we look at other service discovery tools in this field, we have two popular choices. Some major players in the software industry have been using it in the past. These tools areEtcdandZookeeper。
Let's consider the following table to compare the different aspects of each tool. We will also learn about the content each of them uses internally.
| Properties | Consul | Etcd | Zoo Keeper |
| User Interface | Available |  | |
| RPC | Available | Available | |
| Health Check | HTTP API | HTTP API | TCP |
| Key Value | 3 consistency modes | Good consistency | Strong consistency |
| Token System | Available | | |
| Language | Golang | Golang | Java |
Consul - Members and Agents
Consul members can be defined as a list of different proxy and server modes used to deploy the Consul cluster. Consul provides us with a command-line feature that allows us to easily list all agents associated with Consul.
Consul agent is the core process of Consul. Proxy maintenance of membership information, registration services, operation checks, response queries, etc. Any agent can run in one of two modes:ClientorServer. These two modes can be used based on the role determined when using consult. Consul agents provide assistance by providing us with the following information.
Node Name- This is the host name of the machine.
Datacenter- Configure the data center where the agent runs. Each node must be configured to report to its data center.
Server- Indicates whether the agent is running in server mode or client mode. Server nodes participate in consensus arbitration, store cluster status, and process queries.
Client Addr- This is the address used by the proxy for the client interface. It includes ports for HTTP, DNS, and RPC interfaces.
Cluster Addr- It is the set of addresses and ports used for communication between Consul agents in a cluster. All other nodes must have access to this address.
In the next chapter, we will learn about Consul's architecture.