etcd集群

1. 简介

一个用于存储分布式系统中最关键数据的分布式、可靠的键值存储

2. 安装

下载

mkdir /opt/software
cd /opt/software
ETCD_VERSION='3.5.4'
wget https://github.com/etcd-io/etcd/releases/download/v${ETCD_VERSION}/etcd-v${ETCD_VERSION}-linux-amd64.tar.gz
tar -xvf etcd-v${ETCD_VERSION}-linux-amd64.tar.gz
cd etcd-v${ETCD_VERSION}-linux-amd64
sudo cp -a etcd etcdctl /usr/bin/

配置

# This is the configuration file for the etcd server.

# Human-readable name for this member.
name: 'etcd0'

# Path to the data directory.
data-dir: '/var/lib/etcd'

# Path to the dedicated wal directory.
wal-dir: '/var/lib/etcd'

# Number of committed transactions to trigger a snapshot to disk.
snapshot-count: 10000

# Time (in milliseconds) of a heartbeat interval.
heartbeat-interval: 100

# Time (in milliseconds) for an election to timeout.
election-timeout: 1000

# Raise alarms when backend size exceeds the given quota. 0 means use the
# default quota.
quota-backend-bytes: 0

# List of comma separated URLs to listen on for peer traffic.
listen-peer-urls: http://0.0.0.0:2380

# List of comma separated URLs to listen on for client traffic.
listen-client-urls: http://0.0.0.0:2379

# Maximum number of snapshot files to retain (0 is unlimited).
max-snapshots: 5

# Maximum number of wal files to retain (0 is unlimited).
max-wals: 5

# Comma-separated white list of origins for CORS (cross-origin resource sharing).
cors:

# List of this member's peer URLs to advertise to the rest of the cluster.
# The URLs needed to be a comma-separated list.
initial-advertise-peer-urls: http://192.168.56.104:2380

# List of this member's client URLs to advertise to the public.
# The URLs needed to be a comma-separated list.
advertise-client-urls: http://192.168.56.104:2379

# Discovery URL used to bootstrap the cluster.
discovery:

# Valid values include 'exit', 'proxy'
discovery-fallback: 'proxy'

# HTTP proxy to use for traffic to discovery service.
discovery-proxy:

# DNS domain used to bootstrap initial cluster.
discovery-srv:

# Comma separated string of initial cluster configuration for bootstrapping.
# Example: initial-cluster: "infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380"
initial-cluster: 'etcd0=http://192.168.56.104:2380'

# Initial cluster token for the etcd cluster during bootstrap.
initial-cluster-token: 'etcd-cluster'

# Initial cluster state ('new' or 'existing').
initial-cluster-state: 'new'

# Reject reconfiguration requests that would cause quorum loss.
strict-reconfig-check: false

# Enable runtime profiling data via HTTP server
enable-pprof: true

# Valid values include 'on', 'readonly', 'off'
proxy: 'off'

# Time (in milliseconds) an endpoint will be held in a failed state.
proxy-failure-wait: 5000

# Time (in milliseconds) of the endpoints refresh interval.
proxy-refresh-interval: 30000

# Time (in milliseconds) for a dial to timeout.
proxy-dial-timeout: 1000

# Time (in milliseconds) for a write to timeout.
proxy-write-timeout: 5000

# Time (in milliseconds) for a read to timeout.
proxy-read-timeout: 0

client-transport-security:
  # Path to the client server TLS cert file.
  cert-file:

  # Path to the client server TLS key file.
  key-file:

  # Enable client cert authentication.
  client-cert-auth: false

  # Path to the client server TLS trusted CA cert file.
  trusted-ca-file:

  # Client TLS using generated certificates
  auto-tls: false

peer-transport-security:
  # Path to the peer server TLS cert file.
  cert-file:

  # Path to the peer server TLS key file.
  key-file:

  # Enable peer client cert authentication.
  client-cert-auth: false

  # Path to the peer server TLS trusted CA cert file.
  trusted-ca-file:

  # Peer TLS using generated certificates.
  auto-tls: false

  # Allowed CN for inter peer authentication.
  allowed-cn:

  # Allowed TLS hostname for inter peer authentication.
  allowed-hostname:

# The validity period of the self-signed certificate, the unit is year.
self-signed-cert-validity: 1

# Enable debug-level logging for etcd.
log-level: debug

logger: zap

# Specify 'stdout' or 'stderr' to skip journald logging even when running under systemd.
log-outputs: [stderr]

# Force to create a new one member cluster.
force-new-cluster: false

auto-compaction-mode: periodic
auto-compaction-retention: "1"

# Limit etcd to a specific set of tls cipher suites
cipher-suites: [
  TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
  TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
]

# Limit etcd to specific TLS protocol versions
tls-min-version: 'TLS1.2'
tls-max-version: 'TLS1.3'

启动

/usr/bin/etcd --config-file /etc/etcd/conf.yaml

systemd 配置

[Unit]
Description=etcd - Distributed Key Value Store
Documentation=https://etcd.io/docs
After=network.target
Wants=network-online.target
Requires=network-online.target

[Service]
Type=notify
ExecStart=/usr/bin/etcd --config-file /etc/etcd/conf.yaml
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

systemd 管理

systemctl restart etcd
systemctl stop etcd
systemctl start etcd
systemctl status etcd

3. 使用

Cli 存取数据

etcdctl put greeting "Hello, etcd"
etcdctl get greeting
etcdctl get "" --prefix --keys-only #获取所有的 key 值

4. 拓展信息

4.1. 出现 DNS IS Empty 错误

echo nameserver 8.8.8.8

4.2. 出现 open File 1024 错误

root soft nofile 65535
root hard nofile 100000
yangxy soft nofile 65535
yangxy hard nofile 100000

注意：此处的用户信息最好不要使用*来代表所有用户，可能会出现配置不生效的问题

4.3. V2 Vs V3 版本

两个版本之间存在非常大的变动，API 等格式都不一致，请注意对应的版本

5. 参考资料

官方文档