如何判断zookeeper cluster是否可用

如何判断zookeeper cluster是否可用

还没有找到更好的办法，这个办法很土，就是客户端发起命令一个list命令，看看能不能正确得到结果；list的目标可以是根路径(/)，或者其他内置的路径，例如(/zookeeper)。

下面是golang的例子，使用了github.com/samuel/go-zookeeper/zk库文件。

package main

import (
    "log"
    "time"

    "github.com/samuel/go-zookeeper/zk"
)


var ZOOKEEPER_SERVERS = []string { "zookeeper1.example.com:2181",
                                   "zookeeper2.example.com:2181",
                                   "zookeeper3.example.com:2181"}

func main() {
    if checkZookeeper() {
        log.Printf("Check zookeeper status success\n")
    } else {
        log.Printf("Check zookeeper status failure\n")
    }
}

func checkZookeeper() bool {
    conn, events, err := zk.Connect(ZOOKEEPER_SERVERS, time.Second)
    if err != nil {
        log.Printf("ERROR: Cannot connect to zk server, err=[%v]\n", err)
        return false
    }
    defer conn.Close()

Loop:
    for event := range events {
        switch event.State {
        case zk.StateConnecting, zk.StateConnected :
            //continue
        case zk.StateDisconnected:
            log.Printf("ERROR: zk status: disconnected\n")
            return false
        case zk.StateHasSession:
            break Loop
        default:
            log.Printf("ERROR: zk status: %s\n", event.State)
            return false
        }
    }

    children, _, err := conn.Children("/zookeeper")
    if err != nil {
        log.Printf("ERROR: Unable to list children, err=[%v]\n", err)
        return false
    }

    log.Printf("Get total keys count=[%d]\n", len(children))
    for i, child := range children {
        log.Printf("\tChild[%d]: [%s]\n", i, child)
    }

    return true
}