LinDB Client Go

This repository contains the reference Go client for LinDB.

• Features
• How To Use
  • Installation
  • Write Data
  • Reading Background Process Errors
  • Query Data
  • Write Options

Features

• Write data
  • Write data use asynchronous
  • Support field type(sum/min/max/last/first/histogram)
  • FlatBuf Protocol
• Query data
  • Query metric data/metadata

How To Use

Installation

Go 1.19 or later is required.

• Add the client package to your project dependencies (go.mod).

  go get github.com/lindb/client_go

• Add import github.com/lindb/client_go to your source code.

Write data

package main

import (
	"context"
	"fmt"
	"time"

	lindb "github.com/lindb/client_go"
	"github.com/lindb/client_go/api"
)

func main() {
	// create write client with options
	cli := lindb.NewClientWithOptions(
		"http://localhost:9000",
		lindb.DefaultOptions().SetBatchSize(200).
			SetReqTimeout(60).
			SetRetryBufferLimit(100).
			SetMaxRetries(3),
	)
	// get write client
	w := cli.Write("_internal")
	// get error chan
	errCh := w.Errors()
	go func() {
		for err := range errCh {
			fmt.Printf("got err:%s\n", err)
		}
	}()

	// write some metric data
	for i := 0; i < 10; i++ {
		// write cpu data
		w.AddPoint(context.TODO(), api.NewPoint("cpu").
			AddTag("host", "host1").
			AddField(api.NewSum("load", 10.0)).
			AddField(api.NewLast("usage", 24.0)))
		// write memory data
		w.AddPoint(context.TODO(), api.NewPoint("memory").
			AddTag("host", "host1").
			AddField(api.NewLast("used", 10.0)).
			AddField(api.NewLast("total", 24.0)))
	}

	// close write client
	w.Close()
}

Reading background process errors

Write client doesn't log any error. Can use Errors() method, which returns the channel for reading errors occurring during async writes.

package main

import (
	"context"
	"fmt"
	"time"

	"github.com/lindb/client_go"
	"github.com/lindb/client_go/api"
)

func main() {
	// create write client
	cli := lindb.NewClient("http://localhost:9000")
	w := cli.Write("_internal")
	// get error chan
	errCh := w.Errors()
	go func() {
		for err := range errCh {
			fmt.Printf("got err:%s\n", err)
		}
	}()

	// write data
	for i := 0; i < 10; i++ {
		p := api.NewPoint("cpu").
			AddTag("host", "host1").
			AddField(api.NewSum("load", 10.0)).
			AddField(api.NewLast("usage", 24.0))
		w.AddPoint(context.TODO(), p)
	}

	// close write client
	w.Close()
}

Query data

More examples

package main

import (
	"context"
	"fmt"

	lindb "github.com/lindb/client_go"
)

func main() {
	// create write client
	cli := lindb.NewClient("http://localhost:9000")
	query := cli.DataQuery()
	// LinQL ref: https://lindb.io/guide/lin-ql.html#metric-query
	data, err := query.DataQuery(context.TODO(),
		"_internal",
		"select heap_objects from lindb.runtime.mem where time>now()-2m and 'role' in ('Broker') group by node")
	if err != nil {
		fmt.Println(err)
		return
	}
	// print table
	_, table := data.ToTable()
	fmt.Println(table)
}

Options

package http

import "crypto/tls"

type Options struct {
	// Request timeout(s), default 30.
	reqTimeout int64
	// TLS configuration for secure connection, default nil.
	tlsConfig *tls.Config
}

See tls.Config for detail.

package api

type WriteOptions struct {
	// Number of series sent in single write request, default 1000.
	batchSize int
	// Flush interval(ms) which is buffer flushed if it has not been already written, default 1000.
	flushInterval int64
	// Whether to use GZip compress write data, default true.
	useGZip bool
	// Default tags are added to each written series.
	defaultTags map[string]string
	// Maximum count of retry attempts of failed writes, default 3.
	maxRetries int
	// Maximum number of write request to keep for retry, default 100.
	retryBufferLimit int
}