Platforms on etcd

Amazon Web Services

Mon, 01 Jan 0001 00:00:00 +0000

This guide assumes operational knowledge of Amazon Web Services (AWS), specifically Amazon Elastic Compute Cloud (EC2). This guide provides an introduction to design considerations when designing an etcd deployment on AWS EC2 and how AWS specific features may be utilized in that context.

Capacity planning

As a critical building block for distributed systems it is crucial to perform adequate capacity planning in order to support the intended cluster workload. As a highly available and strongly consistent data store increasing the number of nodes in an etcd cluster will generally affect performance adversely. This makes sense intuitively, as more nodes means more members for the leader to coordinate state across. The most direct way to increase throughput and decrease latency of an etcd cluster is allocate more disk I/O, network I/O, CPU, and memory to cluster members. In the event it is impossible to temporarily divert incoming requests to the cluster, scaling the EC2 instances which comprise the etcd cluster members one at a time may improve performance. It is, however, best to avoid bottlenecks through capacity planning.

Container Linux with systemd

Mon, 01 Jan 0001 00:00:00 +0000

The following guide shows how to run etcd with systemd under Container Linux.

Provisioning an etcd cluster

Cluster bootstrapping in Container Linux is simplest with Ignition; coreos-metadata.service dynamically fetches the machine’s IP for discovery. Note that etcd’s discovery service protocol is only meant for bootstrapping, and cannot be used with runtime reconfiguration or cluster monitoring.

The Container Linux Config Transpiler compiles etcd configuration files into Ignition configuration files:

etcd:
 version: 3.2.0
 name: s1
 data_dir: /var/lib/etcd
 advertise_client_urls: http://{PUBLIC_IPV4}:2379
 initial_advertise_peer_urls: http://{PRIVATE_IPV4}:2380
 listen_client_urls: http://0.0.0.0:2379
 listen_peer_urls: http://{PRIVATE_IPV4}:2380
 discovery: https://discovery.etcd.io/<token>

ct would produce the following Ignition Config:

FreeBSD

Mon, 01 Jan 0001 00:00:00 +0000

Starting with version 0.1.2 both etcd and etcdctl have been ported to FreeBSD and can be installed either via packages or ports system. Their versions have been recently updated to 0.2.0 so now etcd and etcdctl can be enjoyed on FreeBSD 10.0 (RC4 as of now) and 9.x, where they have been tested. They might also work when installed from ports on earlier versions of FreeBSD, but it is untested; caveat emptor.