bd332b318e
Calls to Status can be frequent and currently incur three heap allocations, but often the caller has no intention to hold on to the returned status. Add StatusWithoutProgress and WithProgress to allow avoiding heap allocations altogether. StatusWithoutProgress does what's on the tin and additionally returns a value (instead of a pointer) to avoid the associated heap allocation. By not returning a Progress map, it avoids all other allocations that Status incurs. To still introspect the Progress map, add WithProgress, which uses a simple visitor pattern. Add benchmarks to verify that this is indeed allocation free. ``` BenchmarkStatusProgress/members=1/Status-8 5000000 353 ns/op 784 B/op 3 allocs/op BenchmarkStatusProgress/members=1/Status-example-8 5000000 372 ns/op 784 B/op 3 allocs/op BenchmarkStatusProgress/members=1/StatusWithoutProgress-8 100000000 17.6 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=1/WithProgress-8 30000000 48.6 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=1/WithProgress-example-8 30000000 42.9 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=3/Status-8 5000000 395 ns/op 784 B/op 3 allocs/op BenchmarkStatusProgress/members=3/Status-example-8 3000000 449 ns/op 784 B/op 3 allocs/op BenchmarkStatusProgress/members=3/StatusWithoutProgress-8 100000000 18.7 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=3/WithProgress-8 20000000 78.1 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=3/WithProgress-example-8 20000000 70.7 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=5/Status-8 3000000 470 ns/op 784 B/op 3 allocs/op BenchmarkStatusProgress/members=5/Status-example-8 3000000 544 ns/op 784 B/op 3 allocs/op BenchmarkStatusProgress/members=5/StatusWithoutProgress-8 100000000 19.7 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=5/WithProgress-8 20000000 105 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=5/WithProgress-example-8 20000000 94.0 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=100/Status-8 100000 11903 ns/op 22663 B/op 12 allocs/op BenchmarkStatusProgress/members=100/Status-example-8 100000 13330 ns/op 22669 B/op 12 allocs/op BenchmarkStatusProgress/members=100/StatusWithoutProgress-8 50000000 20.9 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=100/WithProgress-8 1000000 1731 ns/op 0 B/op 0 allocs/op BenchmarkStatusProgress/members=100/WithProgress-example-8 1000000 1571 ns/op 0 B/op 0 allocs/op ```
etcd
Note: The master branch may be in an unstable or even broken state during development. Please use releases instead of the master branch in order to get stable binaries.
etcd is a distributed reliable key-value store for the most critical data of a distributed system, with a focus on being:
- Simple: well-defined, user-facing API (gRPC)
- Secure: automatic TLS with optional client cert authentication
- Fast: benchmarked 10,000 writes/sec
- Reliable: properly distributed using Raft
etcd is written in Go and uses the Raft consensus algorithm to manage a highly-available replicated log.
etcd is used in production by many companies, and the development team stands behind it in critical deployment scenarios, where etcd is frequently teamed with applications such as Kubernetes, locksmith, vulcand, Doorman, and many others. Reliability is further ensured by rigorous testing.
See etcdctl for a simple command line client.
Community meetings
Community meeting is put on hold for now.
etcd contributors and maintainers have bi-weekly meetings at 11:00 AM (USA Pacific) on Tuesdays.
An initial agenda will be posted to the shared Google docs a day before each meeting, and everyone is welcome to suggest additional topics or other agendas.
Getting started
Getting etcd
The easiest way to get etcd is to use one of the pre-built release binaries which are available for OSX, Linux, Windows, and Docker on the release page.
For more installation guides, please check out play.etcd.io and operating etcd.
For those wanting to try the very latest version, build the latest version of etcd from the master branch. This first needs Go installed (version 1.11+ is required). All development occurs on master, including new features and bug fixes. Bug fixes are first targeted at master and subsequently ported to release branches, as described in the branch management guide.
Running etcd
First start a single-member cluster of etcd.
If etcd is installed using the pre-built release binaries, run it from the installation location as below:
/tmp/etcd-download-test/etcd
The etcd command can be simply run as such if it is moved to the system path as below:
mv /tmp/etcd-download-test/etcd /usr/local/bin/
etcd
If etcd is built from the master branch, run it as below:
./bin/etcd
This will bring up etcd listening on port 2379 for client communication and on port 2380 for server-to-server communication.
Next, let's set a single key, and then retrieve it:
ETCDCTL_API=3 etcdctl put mykey "this is awesome"
ETCDCTL_API=3 etcdctl get mykey
etcd is now running and serving client requests. For more, please check out:
etcd TCP ports
The official etcd ports are 2379 for client requests, and 2380 for peer communication.
Running a local etcd cluster
First install goreman, which manages Procfile-based applications.
Our Procfile script will set up a local example cluster. Start it with:
goreman start
This will bring up 3 etcd members infra1, infra2 and infra3 and etcd grpc-proxy, which runs locally and composes a cluster.
Every cluster member and proxy accepts key value reads and key value writes.
Next steps
Now it's time to dig into the full etcd API and other guides.
- Read the full documentation.
- Explore the full gRPC API.
- Set up a multi-machine cluster.
- Learn the config format, env variables and flags.
- Find language bindings and tools.
- Use TLS to secure an etcd cluster.
- Tune etcd.
Contact
- Mailing list: etcd-dev
- IRC: #etcd on freenode.org
- Planning/Roadmap: milestones, roadmap
- Bugs: issues
Contributing
See CONTRIBUTING for details on submitting patches and the contribution workflow.
Reporting bugs
See reporting bugs for details about reporting any issues.
Reporting a security vulnerability
Due to their public nature, GitHub and mailing lists are NOT appropriate places for reporting vulnerabilities. Please refer to CoreOS's security disclosure process when reporting issues that may be security related.
License
etcd is under the Apache 2.0 license. See the LICENSE file for details.