2

私がやろうとしていること

私は rabbit-mq パブリッシャーとサブスクライバーを作成しようとしています。rabbit-mq サーバーを再起動しようとするまで、期待どおりに動作します。

機能するもの

rabbitmq:3-managementDocker イメージ、ampqlib 5.3、および Node.jsを使用11.10.0して、この単純なプログラムを作成します。

const q = 'tasks';

const { execSync } = require("child_process");
const amqplib = require("amqplib");

function createChannel() {
    return amqplib.connect("amqp://root:toor@0.0.0.0:5672/")
        .then((conn) => conn.createChannel());
}

Promise.all([createChannel(), createChannel()])

    .then(async (channels) => {
        const [publisherChannel, consumerChannel] = channels;

        // publisher
        await publisherChannel.assertQueue(q).then(function(ok) {
            return publisherChannel.sendToQueue(q, Buffer.from("something to do"));
        });

        // consumer
        await consumerChannel.assertQueue(q).then(function(ok) {
            return consumerChannel.consume(q, function(msg) {
                if (msg !== null) {
                    console.log(msg.content.toString());
                    consumerChannel.ack(msg);
                }
            });
        });

    })

    .catch(console.warn);

ということで、まずはチャンネルを2つ作りました。1 つはパブリッシャーとして、もう 1 つはコンシューマーとして。

パブリッシャーはsomething to doメッセージをtasksキューに送信します。

次に、コンシューマーはメッセージをキャッチし、 を使用して画面に出力しconsole.logます。

期待どおりに動作します。

うまくいかないこと

最初の試み

const q = 'tasks';

const { execSync } = require("child_process");
const amqplib = require("amqplib");

function createChannel() {
    return amqplib.connect("amqp://root:toor@0.0.0.0:5672/")
        .then((conn) => conn.createChannel());
}

Promise.all([createChannel(), createChannel()])

    .then((channels) => {

        // Let's say rabbitmq is down, and then up again
        execSync("docker stop rabbitmq");
        execSync("docker start rabbitmq");

        return channels;
    })

    .then(async (channels) => {
        const [publisherChannel, consumerChannel] = channels;

        // publisher
        await publisherChannel.assertQueue(q).then(function(ok) {
            return publisherChannel.sendToQueue(q, Buffer.from("something to do"));
        });

        // consumer
        await consumerChannel.assertQueue(q).then(function(ok) {
            return consumerChannel.consume(q, function(msg) {
                if (msg !== null) {
                    console.log(msg.content.toString());
                    consumerChannel.ack(msg);
                }
            });
        });

    })

    .catch(console.warn);

前回の試みと同様ですが、今回は続行する前に rabbit-mq コンテナーを停止して開始 (サーバーを再起動) しようとしました。

動作しません。代わりに次のエラーが表示されます。

{ Error: Socket closed abruptly during opening handshake
    at Socket.endWhileOpening (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:260:17)                                                           
    at Socket.emit (events.js:202:15)
    at endReadableNT (_stream_readable.js:1129:12)
    at processTicksAndRejections (internal/process/next_tick.js:76:17)
  cause:
   Error: Socket closed abruptly during opening handshake
       at Socket.endWhileOpening (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:260:17)                                                        
       at Socket.emit (events.js:202:15)
       at endReadableNT (_stream_readable.js:1129:12)
       at processTicksAndRejections (internal/process/next_tick.js:76:17),
  isOperational: true }
[guldan@draenor labs]$ node --version
v11.10.0
[guldan@draenor labs]$ docker start rabbitmq && node test.js
rabbitmq
{ Error: Channel ended, no reply will be forthcoming
    at rej (/home/guldan/Projects/node_modules/amqplib/lib/channel.js:195:7)                                                                                  
    at Channel.C._rejectPending (/home/guldan/Projects/node_modules/amqplib/lib/channel.js:197:28)                                                            
    at Channel.C.toClosed (/home/guldan/Projects/node_modules/amqplib/lib/channel.js:165:8)                                                                   
    at Connection.C._closeChannels (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:394:18)                                                      
    at Connection.C.toClosed (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:401:8)                                                             
    at Object.accept (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:96:18)                                                                     
    at Connection.mainAccept [as accept] (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:64:33)                                                 
    at Socket.go (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:478:48)                                                                        
    at Socket.emit (events.js:197:13)
    at emitReadable_ (_stream_readable.js:539:12)
    at processTicksAndRejections (internal/process/next_tick.js:76:17)
  cause:
   Error: Channel ended, no reply will be forthcoming
       at rej (/home/guldan/Projects/node_modules/amqplib/lib/channel.js:195:7)                                                                               
       at Channel.C._rejectPending (/home/guldan/Projects/node_modules/amqplib/lib/channel.js:197:28)                                                         
       at Channel.C.toClosed (/home/guldan/Projects/node_modules/amqplib/lib/channel.js:165:8)                                                                
       at Connection.C._closeChannels (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:394:18)                                                   
       at Connection.C.toClosed (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:401:8)                                                          
       at Object.accept (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:96:18)                                                                  
       at Connection.mainAccept [as accept] (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:64:33)                                              
       at Socket.go (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:478:48)                                                                     
       at Socket.emit (events.js:197:13)
       at emitReadable_ (_stream_readable.js:539:12)
       at processTicksAndRejections (internal/process/next_tick.js:76:17),
  isOperational: true }

2 回目の試行

私の最初の試みはうまくいきませんでした。したがって、サーバーを再起動した後、新しいチャネルを作成しようとします。

const q = 'tasks';

const { execSync } = require("child_process");
const amqplib = require("amqplib");

function createChannel() {
    return amqplib.connect("amqp://root:toor@0.0.0.0:5672/")
        .then((conn) => conn.createChannel());
}

Promise.all([createChannel(), createChannel()])

    .then((channels) => {

        // Let's say rabbitmq is down, and then up again
        execSync("docker stop rabbitmq");
        execSync("docker start rabbitmq");

        return Promise.all([createChannel(), createChannel()]);
        // return channels;
    })

    .then(async (channels) => {
        const [publisherChannel, consumerChannel] = channels;

        // publisher
        await publisherChannel.assertQueue(q).then(function(ok) {
            return publisherChannel.sendToQueue(q, Buffer.from("something to do"));
        });

        // consumer
        await consumerChannel.assertQueue(q).then(function(ok) {
            return consumerChannel.consume(q, function(msg) {
                if (msg !== null) {
                    console.log(msg.content.toString());
                    consumerChannel.ack(msg);
                }
            });
        });

    })

    .catch(console.warn);

今回は、代わりに次のエラーが発生しました。

{ Error: Socket closed abruptly during opening handshake
    at Socket.endWhileOpening (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:260:17)                                                           
    at Socket.emit (events.js:202:15)
    at endReadableNT (_stream_readable.js:1129:12)
    at processTicksAndRejections (internal/process/next_tick.js:76:17)
  cause:
   Error: Socket closed abruptly during opening handshake
       at Socket.endWhileOpening (/home/guldan/Projects/node_modules/amqplib/lib/connection.js:260:17)                                                        
       at Socket.emit (events.js:202:15)
       at endReadableNT (_stream_readable.js:1129:12)
       at processTicksAndRejections (internal/process/next_tick.js:76:17),
  isOperational: true }

よくわかりませんが、エラーはhttps://github.com/squaremo/amqp.node/issues/101に関連している可能性があります。

私が欲しいもの

サーバーの再起動後にrabbitmqに再接続するための回避策/解決策が必要です。説明/提案も歓迎します。

編集

さらに深く掘り下げて、コードを少し変更してみます。

const q = 'tasks';

const { execSync } = require("child_process");
const amqplib = require("amqplib");

async function createConnection() {
    console.log("connect");
    const conn = amqplib.connect("amqp://root:toor@0.0.0.0:5672/");
    console.log("connected");
    return conn;
}

async function createChannel(conn) {
    console.log("create channel");
    const channel = conn.createChannel({durable: false});
    console.log("channel created");
    return channel;
}

async function createConnectionAndChannel() {
    const conn = await createConnection();
    const channel = await createChannel(conn);
    return channel;
}

Promise.all([createConnectionAndChannel(), createConnectionAndChannel()])

    .then((channels) => {

        // Let's say rabbitmq is down, and then up again
        console.log("restart server");
        execSync("docker stop rabbitmq");
        execSync("docker start rabbitmq");
        console.log("server restarted");

        return Promise.all([createConnectionAndChannel(), createConnectionAndChannel()]);
        // return channels;
    })

    .then(async (channels) => {
        console.log("channels created");
        const [publisherChannel, consumerChannel] = channels;

        // publisher
        console.log("publish");
        await publisherChannel.assertQueue(q).then(function(ok) {
            console.log("published");
            return publisherChannel.sendToQueue(q, Buffer.from("something to do"));
        });

        // consumer
        console.log("consume");
        await consumerChannel.assertQueue(q).then(function(ok) {
            console.log("consumed");
            return consumerChannel.consume(q, function(msg) {
                if (msg !== null) {
                    console.log(msg.content.toString());
                    consumerChannel.ack(msg);
                }
            });
        });

    })

    .catch(console.warn);

そして、私はこの出力を取得します:

connect
connected
connect
connected
create channel
channel created
create channel
channel created
restart server
server restarted
connect
connected
connect
connected
{ Error: Socket closed abruptly during opening handshake
    at Socket.endWhileOpening (/home/guldan/Projects/kata/merapi-plugin-service-rabbit/node_modules/amqplib/lib/connection.js:260:17)                                                                                             
    at Socket.emit (events.js:202:15)
    at endReadableNT (_stream_readable.js:1129:12)
    at processTicksAndRejections (internal/process/next_tick.js:76:17)
  cause:
   Error: Socket closed abruptly during opening handshake
       at Socket.endWhileOpening (/home/guldan/Projects/kata/merapi-plugin-service-rabbit/node_modules/amqplib/lib/connection.js:260:17)                                                                                          
       at Socket.emit (events.js:202:15)
       at endReadableNT (_stream_readable.js:1129:12)
       at processTicksAndRejections (internal/process/next_tick.js:76:17),
  isOperational: true }

したがって、 amqplib は再接続できますが、 channel の作成に失敗すると思います。

4

3 に答える 3