知行 合一

InfluxDB 高可用

2020.09.29

influxdb 开源版本不支持集群模式，社区开源的方案有多种，本文主要介绍官方提供的高可用方案 influxdb-relay。

架构图

        ┌─────────────────┐                 
        │writes & queries │                 
        └─────────────────┘                 
                 │                          
                 ▼                          
         ┌───────────────┐                  
         │               │                  
┌────────│ Load Balancer │─────────┐        
│        │               │         │        
│        └──────┬─┬──────┘         │        
│               │ │                │        
│               │ │                │        
│        ┌──────┘ └────────┐       │        
│        │ ┌─────────────┐ │       │┌──────┐
│        │ │/write or UDP│ │       ││/query│
│        ▼ └─────────────┘ ▼       │└──────┘
│  ┌──────────┐      ┌──────────┐  │        
│  │ InfluxDB │      │ InfluxDB │  │        
│  │ Relay    │      │ Relay    │  │        
│  └──┬────┬──┘      └────┬──┬──┘  │        
│     │    |              |  │     │        
│     |  ┌─┼──────────────┘  |     │        
│     │  │ └──────────────┐  │     │        
│     ▼  ▼                ▼  ▼     │        
│  ┌──────────┐      ┌──────────┐  │        
│  │          │      │          │  │        
└─▶│ InfluxDB │      │ InfluxDB │◀─┘        
   │          │      │          │           
   └──────────┘      └──────────┘

架构比较简单，由一个负载均衡器、两个或多个 InfluxDB Relay 和两个或多个 InfluxDB 后端数据库组成。InfluxDB Relay 对外提供 http 服务，写请求可通 http 或 udp 方式向 influxdb 写入数据，不支持读请求，也不支持数据库 schema 的修改( create、drop等 )。在写入数据之前必须预先创建好数据库。

集群节点

Node Role
192.168.1.5 influxdb-relay
192.168.1.6 influxdb
192.168.1.7 influxdb

安装 influxdb

$ wget https://dl.influxdata.com/influxdb/releases/influxdb-1.8.2.x86_64.rpm
$ yum install -y influxdb-1.8.2.x86_64.rpm

// 启动服务
$ systemctl start influxdb.service

部署 influxdb-relay

安装 Golang

$ wget https://dl.google.com/go/go1.15.2.linux-amd64.tar.gz
$ tar -C /usr/local -xzf go1.15.2.linux-amd64.tar.gz

// 写入环境变量
$ vi ~/.bash_profile
...
PATH=$PATH:$HOME/bin:/usr/local/go/bin
...

$ source ~/.bash_profile
$ go version
go version go1.15.2 linux/amd64

安装 influxdb-relay

$ yum install git -y
$ go get -u github.com/influxdata/influxdb-relay
$ mkdir /etc/influxdb-relay
$ cp $GOPATH/src/github.com/influxdata/influxdb-relay/sample.toml /etc/influxdb-relay/relay.toml
// 编辑配置文件
$ cat /etc/influxdb-relay/relay.toml
[[http]]
name = "influx-http"
bind-addr = "127.0.0.1:9096"
output = [
    { name="db1", location = "http://192.168.1.6:8086/write" },
    { name="db2", location = "http://192.168.1.7:8086/write" },
]

systemd 守护进程

$ cp /root/go/bin/influxdb-relay /usr/local/bin/
// 编辑 systemd service 配置
$ cat /etc/systemd/system/influxdb-relay.service
[Unit]
Description=influxdb relay
After=syslog.target
After=network.target

[Service]
Type=simple
ExecStart=/usr/local/bin/influxdb-relay -config /etc/influxdb-relay/relay.toml
Restart=always
ProtectSystem=full
PrivateDevices=yes
PrivateTmp=yes
NoNewPrivileges=true

[Install]
WantedBy=multi-user.target

nginx 代理

influxdb-relay 提供双写策略，读请求可通过 nginx 进行代理转发

$ cat /etc/nginx/conf.d/influxdb-relay.conf

upstream db {
    ip_hash;
    server 192.168.1.6:8086 max_fails=1 fail_timeout=10s;
    server 192.168.1.7:8086 max_fails=1 fail_timeout=10s;
}

server {
    listen 9097;
    location /ping {
        proxy_pass http://db;
    }
    location /query {
        proxy_pass http://db;
    }
		location /write {
        limit_except POST {
            deny all;
        }
        proxy_pass http://127.0.0.1:9096;
    }
}

测试

write

$ curl -i  -XPOST http://192.168.1.5:9096/write\?db\=quark_test --data-binary 'cpu_usage,host=master1 value=0.2'
HTTP/1.1 204 No Content
Date: Sun, 27 Sep 2020 07:44:53 GMT

192.168.1.6

$ influx  -precision rfc3339 -database quark_test
Connected to http://localhost:8086 version 1.8.2
InfluxDB shell version: 1.8.2
> select * from cpu_usage;
name: cpu_usage
time                           host    value
----                           ----    -----
2020-09-27T07:44:53.912364901Z master1 0.2

192.168.1.7

$ influx  -precision rfc3339 -database quark_test
Connected to http://localhost:8086 version 1.8.2
InfluxDB shell version: 1.8.2
> select * from cpu_usage;
name: cpu_usage
time                           host    value
----                           ----    -----
2020-09-27T07:44:53.912364901Z master1 0.2

read

$ curl -i -XPOST http://192.168.1.5:9097/query\?db\=quark_test --data-urlencode "q=select * from cpu_usage"

{"results":[{"statement_id":0,"series":[{"name":"cpu_usage","columns":["time","host","value"],"values":[["2020-09-27T07:44:53.912364901Z","master1",0.2],["2020-09-27T07:57:01.88854361Z","master1",0.3],["2020-09-27T09:04:08.122066387Z","master1",0.4],["2020-09-27T09:05:29.693797445Z","master1",0.5]]}]}]}

参考