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* Adds redirects for Getting Started pages * Uses correct links to resources at learn.hashicorp * Reconfigures "Learn more" links to point to learn.hashicorp * Links to learn.hashicorp on segmentation page * Adds redirect for sample config file * Fixes links to Getting Started guide on learn.hashicorp * Remove getting started guide which is now on learn.hashicorp * Corrects link to `consul/io` which should go to `consul.io` * Revert "Remove getting started guide which is now on learn.hashicorp" This reverts commit 2cebacf402f83fb936718b41ac9a27415f4e9f21 so a placeholder message can be written here while we are transitioning content to learn.hashicorp * Adding a new page for getting started to direct users to learn. * Added a note at the being of each doc to notify users about the temporary repo change. * Revert "Added a note at the being of each doc to notify users about the temporary repo change." This reverts commit 9a2a8781f9705028e4f53f758ef235e74b2b7198. From conversation at https://github.com/hashicorp/consul/pull/4878 * Removes redirect from sample web.json demo file * Removed typo
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| layout | page_title | sidebar_current | description |
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| intro | Introduction | what | Welcome to the intro guide to Consul! This guide is the best place to start with Consul. We cover what Consul is, what problems it can solve, how it compares to existing software, and how you can get started using it. If you are familiar with the basics of Consul, the documentation provides a more detailed reference of available features. |
Introduction to Consul
Welcome to the intro guide to Consul! This guide is the best place to start with Consul. We cover what Consul is, what problems it can solve, how it compares to existing software, and how you can get started using it. If you are familiar with the basics of Consul, the documentation provides a more detailed reference of available features.
What is Consul?
Consul is a service mesh solution providing a full featured control plane with service discovery, configuration, and segmentation functionality. Each of these features can be used individually as needed, or they can be used together to build a full service mesh. Consul requires a data plane and supports both a proxy and native integration model. Consul ships with a simple built-in proxy so that everything works out of the box, but also supports 3rd party proxy integrations such as Envoy.
The key features of Consul are:
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Service Discovery: Clients of Consul can register a service, such as
apiormysql, and other clients can use Consul to discover providers of a given service. Using either DNS or HTTP, applications can easily find the services they depend upon. -
Health Checking: Consul clients can provide any number of health checks, either associated with a given service ("is the webserver returning 200 OK"), or with the local node ("is memory utilization below 90%"). This information can be used by an operator to monitor cluster health, and it is used by the service discovery components to route traffic away from unhealthy hosts.
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KV Store: Applications can make use of Consul's hierarchical key/value store for any number of purposes, including dynamic configuration, feature flagging, coordination, leader election, and more. The simple HTTP API makes it easy to use.
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Secure Service Communication: Consul can generate and distribute TLS certificates for services to establish mutual TLS connections. Intentions can be used to define which services are allowed to communicate. Service segmentation can be easily managed with intentions that can be changed in real time instead of using complex network topologies and static firewall rules.
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Multi Datacenter: Consul supports multiple datacenters out of the box. This means users of Consul do not have to worry about building additional layers of abstraction to grow to multiple regions.
Consul is designed to be friendly to both the DevOps community and application developers, making it perfect for modern, elastic infrastructures.
Basic Architecture of Consul
Consul is a distributed, highly available system. This section will cover the basics, purposely omitting some unnecessary detail, so you can get a quick understanding of how Consul works. For more detail, please refer to the in-depth architecture overview.
Every node that provides services to Consul runs a Consul agent. Running an agent is not required for discovering other services or getting/setting key/value data. The agent is responsible for health checking the services on the node as well as the node itself.
The agents talk to one or more Consul servers. The Consul servers are where data is stored and replicated. The servers themselves elect a leader. While Consul can function with one server, 3 to 5 is recommended to avoid failure scenarios leading to data loss. A cluster of Consul servers is recommended for each datacenter.
Components of your infrastructure that need to discover other services or nodes can query any of the Consul servers or any of the Consul agents. The agents forward queries to the servers automatically.
Each datacenter runs a cluster of Consul servers. When a cross-datacenter service discovery or configuration request is made, the local Consul servers forward the request to the remote datacenter and return the result.
Next Steps
- See how Consul compares to other software to assess how it fits into your existing infrastructure.
- Continue onwards with the getting started guide to get Consul up and running.