informat.mq Message Queue

Overview

Use informat.mq to perform message queue operations

basicGet

Pull messages from the queue

informat.mq.basicGet(module, queue, autoAck);

Parameter	Type	Description
module	String	Message queue module identifier
queue	String	Queue identifier
autoAck	Boolean	Set whether to auto-acknowledge. Generally set to false, i.e., no auto-acknowledgment

Return Value

Type is MqMessage

TIP

If you want to get a single message, use pull mode. However, you should not use loop pull mode to replace push mode as this will seriously affect performance.

Example

Call

var message = informat.mq.basicGet("mq", "TaskQueue", true);
console.log("message", message);

Return Value

{
  "body": "{\r\n\t'taskId':'1',\r\n\t'taskStatus':'finished'\r\n}",
  "props": {
    "contentLength": 0,
    "deliveryTag": 1,
    "finalRetryForMessageWithNoId": false,
    "headers": {},
    "lastInBatch": false,
    "messageCount": 0,
    "projectionUsed": false,
    "publishSequenceNumber": 0,
    "receivedDeliveryMode": "NON_PERSISTENT",
    "receivedExchange": "",
    "receivedRoutingKey": "croe0zft168y3-skyduxiaoxiduilie-Test1",
    "redelivered": false
  }
}

publish

Send messages to the queue

informat.mq.publish(moduleKey, routingKey, setting, message);

Parameter	Type	Description
module	String	Message queue module identifier
routingKey	String	Routing key
setting	PublishSetting	Publish settings
message	String	Message to send

INFO

• If setting.waitForConfirms is enabled, it will wait for the message queue to confirm that the message has been delivered successfully after message delivery. If delivery fails, an exception will be thrown
• Enabling setting.waitForConfirms will affect delivery performance, but it can ensure successful delivery

Example

//
let body = {
  taskId: "1",
  taskStatus: "finished",
};
informat.mq.publish("mq", "TaskQueue", null, JSON.stringify(body));

queuePurge

Clear the queue

informat.mq.queuePurge(module, queue);

Parameter	Type	Description
module	String	Message queue module identifier
queue	String	Queue identifier

Example

Send message queue after task completion

informat.mq.queuePurge("mq", "TaskQueue");

basicAck

After receiving the message, manually acknowledge successful data reception

informat.mq.basicAck(message, multiple);

Parameter	Type	Description
message	MqMessage	Message object
multiple	Boolean	Whether to support batch confirmation

Example

// Received task completion message event
informat.mq.basicAck(message, true);

basicNack

Nack rejection method Allows consumers to reject a message and optionally requeue it or discard it

informat.mq.basicNack(message, multiple, requeue);

Parameter	Type	Description
message	MqMessage	Message object
multiple	Boolean	If false, indicates the message with this deliveryTag is rejected. If true, all messages with deliveryTag less than this one are rejected.
requeue	Boolean	Whether to redeliver to the queue

Example

informat.mq.basicNack(message, true, true);

basicReject

Reject rejection When a message is rejected and requeue is false, the message will be delivered to the dead letter queue

informat.mq.basicReject(message, requeue);

Parameter	Type	Description
message	MqMessage	Message object
requeue	Boolean	Whether to redeliver to the queue

Example

informat.mq.basicReject(message, true);

basicRecover

Resend unacknowledged messages

informat.mq.basicRecover(message, requeue);

Parameter	Type	Description
message	MqMessage	Message object
requeue	Boolean	If requeue is true, unacknowledged messages will be re-added to the queue, so the same message may be assigned to a different consumer than before. If false, the same message will be assigned to the same consumer as before

Example

informat.mq.basicRecover(message, true);

What to do if you accidentally delete a queue in the message queue backend?

• You can find the corresponding message queue in the configuration interface of the Informat message queue module, edit it, and republish it. The platform will automatically create the message queue.