influxdb 2.0安裝和使用

• influxdb是一個開源的時序數據庫，開源版本只支持單機+高可用，商業版本才支持集羣（橫向擴展/分片）功能
• 安裝參考 https://docs.influxdata.com/influxdb/v2.0/get-started/?t=Docker

  cd ~
  
  mkdir influxdb-data && cd $_
  
  sudo docker run -d \
  --name influxdb \
  -p 8086:8086 \
  --volume $PWD:/root/.influxdbv2 \
  influxdb:2.0.4
  

• 代碼參考(golang)

package main

import (
	"context"
	"fmt"
	"log"
	"math/rand"
	"time"

	influxdb2 "github.com/influxdata/influxdb-client-go/v2"
)

func main() {
	// You can generate a Token from the "Tokens Tab" in the UI
	const token = "Uok6jfbNdqUWSIZyaH0aqxrSvSC1vg5WS5UyJHWciqY_FvkfOGxqHox_EbbvJQwRXQ770gUQqD1ZcXWvTjPFrA=="
	const bucket = "test"
	const org = "you_org"

	client := influxdb2.NewClient("http://192.168.1.11:8086", token)
	// always close client at the end
	defer client.Close()
	write(client, bucket, org)
}

func write(client influxdb2.Client, bucket, org string) {
	// get non-blocking write client
	writeAPI := client.WriteAPI(org, bucket)

	now := time.Now()
	times := 0
	// 10個設備 (60*60*24*365)*10=315360000。約3.1億條數據
	for i := 0; i < 10; i++ {
		// 過去一年
		start := now.Add(-8760 * time.Hour)
		for now.After(start) {
			// write line protocol
			p := influxdb2.NewPointWithMeasurement("設備信息").
				AddTag("設備id", fmt.Sprint(i)).
				AddField("壓力", rand.Float32()*100).
				AddField("溫度", rand.Float32()*30).SetTime(start)
			start = start.Add(1 * time.Second)
			writeAPI.WritePoint(p)
			if times == 10000 {
				log.Printf("當前設備id: %s, 本次寫入 %d 條, 最後一條時間: %s", fmt.Sprint(i), times, start.Format("2006-01-02 15:04:05"))
				times = 0
				// Flush writes
				writeAPI.Flush()
			} else {
				times++
			}
		}
		// Flush writes
		writeAPI.Flush()
	}

}

func query(client influxdb2.Client, bucket, org string) {
	query := fmt.Sprintf("from(bucket:\"%v\")|> range(start: -1h) |> filter(fn: (r) => r._measurement == \"stat\")", bucket)
	// Get query client
	queryAPI := client.QueryAPI(org)
	// get QueryTableResult
	result, err := queryAPI.Query(context.Background(), query)
	if err == nil {
		// Iterate over query response
		for result.Next() {
			// Notice when group key has changed
			if result.TableChanged() {
				fmt.Printf("table: %s\n", result.TableMetadata().String())
			}
			// Access data
			fmt.Printf("%s value: %v\n", result.Record().Field(), result.Record().Value())
		}
		// check for an error
		if result.Err() != nil {
			fmt.Printf("query parsing error: %s\n", result.Err().Error())
		}
	} else {
		panic(err)
	}
}

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