b623af776b
The design of the session TTLs is based on the Google Chubby approach (http://research.google.com/archive/chubby-osdi06.pdf). The Session struct has an additional TTL field now. This attaches an implicit heartbeat based failure detector. Tracking of heartbeats is done by the current leader and not persisted via the Raft log. The implication of this is during a leader failover, we do not retain the last heartbeat times. Similar to Chubby, the TTL represents a lower-bound. Consul promises not to terminate a session before the TTL has expired, but is allowed to extend the expiration past it. This enables us to reset the TTL on a leader failover. The TTL is also extended when the client does a heartbeat. Like Chubby, this means a TTL is extended on creation, heartbeat or failover. Additionally, because we must account for time requests are in transit and the relative rates of clocks on the clients and servers, Consul will take the conservative approach of internally multiplying the TTL by 2x. This helps to compensate for network latency and clock skew without violating the contract. Reference: https://docs.google.com/document/d/1Y5-pahLkUaA7Kz4SBU_mehKiyt9yaaUGcBTMZR7lToY/edit?usp=sharing |
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| acl | ||
| bench | ||
| command | ||
| consul | ||
| demo/vagrant-cluster | ||
| deps | ||
| scripts | ||
| terraform | ||
| test | ||
| testutil | ||
| tlsutil | ||
| ui | ||
| watch | ||
| website | ||
| .gitattributes | ||
| .gitignore | ||
| .travis.yml | ||
| CHANGELOG.md | ||
| LICENSE | ||
| Makefile | ||
| README.md | ||
| Vagrantfile | ||
| commands.go | ||
| main.go | ||
| main_test.go | ||
| version.go | ||
README.md
Consul 
- Website: http://www.consul.io
- IRC:
#consulon Freenode - Mailing list: Google Groups
Consul is a tool for service discovery and configuration. Consul is distributed, highly available, and extremely scalable.
Consul provides several key features:
-
Service Discovery - Consul makes it simple for services to register themselves and to discover other services via a DNS or HTTP interface. External services such as SaaS providers can be registered as well.
-
Health Checking - Health Checking enables Consul to quickly alert operators about any issues in a cluster. The integration with service discovery prevents routing traffic to unhealthy hosts and enables service level circuit breakers.
-
Key/Value Storage - A flexible key/value store enables storing dynamic configuration, feature flagging, coordination, leader election and more. The simple HTTP API makes it easy to use anywhere.
-
Multi-Datacenter - Consul is built to be datacenter aware, and can support any number of regions without complex configuration.
Consul runs on Linux, Mac OS X, and Windows. It is recommended to run the Consul servers only on Linux, however.
Quick Start
An extensive quick quick start is viewable on the Consul website:
http://www.consul.io/intro/getting-started/install.html
Documentation
Full, comprehensive documentation is viewable on the Consul website:
Developing Consul
If you wish to work on Consul itself, you'll first need Go installed (version 1.2+ is required). Make sure you have Go properly installed, including setting up your GOPATH.
Next, clone this repository into $GOPATH/src/github.com/hashicorp/consul and
then just type make. In a few moments, you'll have a working consul executable:
$ go get -u ./...
$ make
...
$ bin/consul
...
note: make will also place a copy of the binary in the first part of your $GOPATH
You can run tests by typing make test.
If you make any changes to the code, run make format in order to automatically
format the code according to Go standards.