hack.go

// super quick hack to test mongodb replica set.  once the replica set is running 
// attemtp rs.stepDown() or just kill the primary and observe the behavior.
package main

import (
	"fmt"
	mgo "gopkg.in/mgo.v2"
	"time"
)

type Person struct {
	Number int
}

func main() {
	session, err := mgo.Dial("mongodb://192.168.99.100:30001,192.168.99.100:30002,192.168.99.100:30003/test")
	if err != nil {
		panic(err)
	}

	// goroutine pings every 2 seconds and will refresh if it gets an error
	go func() {
		for {
			time.Sleep(time.Duration(10 * time.Second))
			copiedSession := session.Clone()
			defer copiedSession.Close()
			if err := copiedSession.Ping(); err != nil {
				fmt.Printf("error pinging server: %#v\n", err)
				session.Refresh()
			} else {
				fmt.Println("ping")
			}
		}
	}()

	var count = 0

	// goroutine attempts a write every 2 seconds to see if we can recover from primary takedown
	go func() {
		for {
			time.Sleep(time.Duration(1 * time.Second))
			count = count + 1
			copiedSession := session.Clone()
			defer copiedSession.Close()
			var person = &Person{
				Number: count,
			}
			if err := copiedSession.DB("test").C("people").Insert(person); err != nil {
				fmt.Printf("error writing to collection: %#v\n", err)
			} else {
				fmt.Println(count)
			}

		}
	}()

	// never quit
	for {
		time.Sleep(time.Duration(1 * time.Minute))
	}
}