64271289ec
There are some cross-config-entry relationships that are enforced during "graph validation" at persistence time that are required to be maintained. This means that config entries may form a digraph at times. Config entry replication procedes in a particular sorted order by kind and name. Occasionally there are some fixups to these digraphs that end up replicating in the wrong order and replicating the leaves (ingress-gateway) before the roots (service-defaults) leading to replication halting due to a graph validation error related to things like mismatched service protocol requirements. This PR changes replication to give each computed change (upsert/delete) a fair shot at being applied before deciding to terminate that round of replication in error. In the case where we've simply tried to do the operations in the wrong order at least ONE of the outstanding requests will complete in the right order, leading the subsequent round to have fewer operations to do, with a smaller likelihood of graph validation errors. This does not address all scenarios, but for scenarios where the edits are being applied in the wrong order this should avoid replication halting. Fixes #9319 The scenario that is NOT ADDRESSED by this PR is as follows: 1. create: service-defaults: name=new-web, protocol=http 2. create: service-defaults: name=old-web, protocol=http 3. create: service-resolver: name=old-web, redirect-to=new-web 4. delete: service-resolver: name=old-web 5. update: service-defaults: name=old-web, protocol=grpc 6. update: service-defaults: name=new-web, protocol=grpc 7. create: service-resolver: name=old-web, redirect-to=new-web If you shutdown dc2 just before (4) and turn it back on after (7) replication is impossible as there is no single edit you can make to make forward progress.
Consul
Consul is a distributed, highly available, and data center aware solution to connect and configure applications across dynamic, distributed infrastructure.
- Website: https://www.consul.io
- Tutorials: HashiCorp Learn
- Forum: Discuss
Consul provides several key features:
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Multi-Datacenter - Consul is built to be datacenter aware, and can support any number of regions without complex configuration.
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Service Mesh/Service Segmentation - Consul Connect enables secure service-to-service communication with automatic TLS encryption and identity-based authorization. Applications can use sidecar proxies in a service mesh configuration to establish TLS connections for inbound and outbound connections without being aware of Connect at all.
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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.
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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.
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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.
Consul runs on Linux, macOS, FreeBSD, Solaris, and Windows and includes an optional browser based UI. A commercial version called Consul Enterprise is also available.
Please note: We take Consul's security and our users' trust very seriously. If you believe you have found a security issue in Consul, please responsibly disclose by contacting us at security@hashicorp.com.
Quick Start
A few quick start guides are available on the Consul website:
- Standalone binary install: https://learn.hashicorp.com/tutorials/consul/get-started-install
- Minikube install: https://learn.hashicorp.com/tutorials/consul/kubernetes-minikube
- Kind install: https://learn.hashicorp.com/tutorials/consul/kubernetes-kind
- Kubernetes install: https://learn.hashicorp.com/tutorials/consul/kubernetes-deployment-guide
Documentation
Full, comprehensive documentation is available on the Consul website:
Contributing
Thank you for your interest in contributing! Please refer to CONTRIBUTING.md for guidance. For contributions specifically to the browser based UI, please refer to the UI's README.md for guidance.