How do you store data across a Kubernetes container cluster? With etcd. This essential part of Kubernetes has been managed by CoreOS/Red Hat. No longer. Now, the open-source etcd project has been moved from Red Hat to the Cloud Native Computing Foundation (CNCF).
What is etcd? No, it's not what happens when a cat tries to type a three-letter acronyms. Etcd (pronounced et-see-dee) was created by the CoreOS team in 2013. It's an open-source, distributed, consistent key-value database for shared configuration, service discovery, and scheduler coordination. It's built on the Raft consensus algorithm for replicated logs.
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Etcd's job is to safely store critical data for distributed systems. It's best known as Kubernetes' primary datastore, but it can be used for other projects. For example, "Alibaba uses etcd for several critical infrastructure systems, given its superior capabilities in providing high availability and data reliability," said Xiang Li, an Alibaba senior staff engineer.
When applications use etcd they have more consistent uptime. Even when individual servers fail, etcd ensures that services keep working. This doesn't just protect against what would otherwise prove show-stopping failures, it also makes it possible to automatic update systems without downtime. You can also use it to coordinate work between servers and set up container overlay networking.
In his KubeCon keynote, Brandon Philips, CoreOS CTO, said: "Today we're excited to transfer stewardship of etcd to the same body that cares for the growth and maintenance of Kubernetes. Given that etcd powers every Kubernetes cluster, this move brings etcd to the community that relies on it most at the CNCF."
That doesn't mean Red Hat is walking away from etcd. Far from it. Red Hat will continue to help develop etcd. After all, etcd is is an essential part of Red Hat's enterprise Kubernetes product, Red Hat OpenShift.
Moving forward, etcd will only grow stronger. It being used by more and more companies, as Kubernetes is adopted by almost every cloud container company. In particular, Phillips said, he expects far more work to be done on etcd security.
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