Send Bulk Notifications and Track Delivery Status - RabbitMq Publishing Part 2 — Jack Vanlightly (2023)

The code for this blog post can be found atGithubGenericName.

This is a console application that creates an exchange and queue for you and allows you to send bulk messages with message delivery status tracking.

First, we'll look at the following design decision you're likely to encounter when running reliable bulk transport operations.

Performance/duplication compensation

When sending messages in bulk, you want decent performance and reliability—you have two conflicting concerns. When I say reliability, I mean that every message must be delivered, and ideally you want to avoid duplicate messages.

The problem is that during a connection failure, the more unacknowledged messages you have, the more duplicate messages you will have if you retry messages that were never acknowledged. However, for performance reasons, you want to maximize your unacknowledged messages in transit.

RabbitMq can send a single ACK to thousands of messages. It will set the "multiple" flag in the ACK. This means that all messages have been acknowledged up to and including this sequence number (delivery tag) and from the last ACK sequence number (or 1 if this is the first ACK number). So if you call BasicPublish 100,000 times and then call WaitForConfirms, RabbitMq can only send a handful of ACKs to cover all the messages. This is great for performance as we may have hundreds or thousands of messages waiting for a response.

But this becomes a problem when a connection fails, as the hundreds of messages sent without an ACK are now a headache. Were they delivered or not? I guess some made it and some didn't. Resending these messages will ensure that they all end up in one queue, but you will likely end up with many that now have two copies in the queue.

(Video) RabbitMQ vs Kafka Part II - Jack Vanlightly | Erlang Solutions Webinar

Then you can call WaitForConfirms after each message. We only have one message in transit at a time, so if a connection fails, we have less of a problem on our hands. We want at most one message without an ACK. But the show stinks!

Therefore, you can call WaitForConfirms periodically to create batches of messages. Batch size depends on your situation and how you want to trade off performance against possible message duplication when republishing messages.

message tracking

BasicPublish is asynchronous. Acknowledgments and callbacks come from event handlers. So how do we associate BasicPublish calls with event handler firings?

We do this through a combination of Serial Number (Delivery Label) and MessageId. BasicAcks and BasicNacks return a delivery tag (sequence number), but BasicReturn only returns the message (with a MessageId), not the delivery tag. So, to trace the BasicReturn, we make sure that each message has a MessageId property that we can use for tracing purposes.

In the code on GitHub we have an IMessageTrackerand a MessageTrackerconcrete. What this class does is store all the messages that will be sent, each grouped into a MessageState class, which contains information such as shipment status, shipment quantity, etc.

We have different mission states that cover the failure scenarios we discussed in the previous part.

public enum SendStatus{ PendingSend, // haven't sent message yet PendingResponse, // message sent, waiting for success, // received failure, // nack received Unroutable, // message returned NoExchangeFound // response code 404 }
private void Callback(BasicAckEventArgs ea, MessageTrackermessageTracker){ if (ea.Multiple) messageTracker.SetMultipleStatus(ea.DeliveryTag, SendStatus.Success); else messageTracker.SetStatus(ea.DeliveryTag, SendStatus.Success);}privat void NackCallback(BasicNackEventArgs ea, MessageTrackermessageTracker){ if (ea.Multiple) messageTracker.SetMultipleStatus(ea.DeliveryTag, SendStatus.Failed) ; else messageTracker.SetStatus(ea.DeliveryTag, SendStatus.Failed);}privat void ReturneretCallback(BasicReturnEventArgs ea, MessageTrackermessageTracker){ messageTracker.SetStatus(ea.BasicProperties.MessageId, SendStatus.Unroutable, string.Format( "Reply Code: {0} Reply Text: {1}", ea.ReplyCode, ea.ReplyText));}private void ModelSh(ShutdownEventArgs ea, MessageTrackermessageTracker){ if (ea.ReplyCode != 200) messageTracker.RegisterChannelClosed("Reply Code: " + ea.ReplyCode + "ReplyText: " + ea.ReplyText);}
(Video) RabbitMQ- Tutorial 7 - Competing Consumers
// cria a mensage RabbitMq a parter de MessagePayload (a row class) var messageJson = JsonConvert.SerializeObject(messageState.MessagePayload); var body = Encoding.UTF8.GetBytes(messageJson); var properties = channel.Properties. Persistent = true; properties.MessageId = messageState.MessageId; properties.Headers = ny ordbog();if (messageState.SendCount > 0) properties.Headers.Add("republished", true);// obtenha o próximo numbero de sequência (tag de entrega) and registre-o com este objectvar MessageState deliveryTag = channel.NextPublishSeq ;messageTracker.SetDeliveryTag(deliveryTag, messageState);messageState.Status = SendStatus.PendingResponse;messageState.SendCount++;// envie a mensagemtry{ kanal.BasicPublish (troca:Roca:Roca:Roca:Roca:Roca:Roca:Roca:Roca:Roca:Roca:Roca:Roca: deiro); if (tæller % messageBatchSize == 0) channel.WaitForConfirms(TimeSpan.FromMinutes(1));}catch (OperationInterruptedException ex){ if (π.χ.ShutdownReason.ReplyCode == 404) messageTracker.SetStatusEtception.SetationsExmes Mensagem); else messageTracker.SetStatus(messageState.MessageId, SendStatus.Failed, ex.Message);}catch (Exceção ex){ messageTracker.SetStatus(messageState.MessageId, SendStatus.Failed, ex.Mes);}

Once all messages have been sent and all acknowledgments received or acknowledgments have timed out, we return the MessageTracker class as IMessageTrackerfor the dialing code. The calling code can inspect this tracer to know the final sent status of each message.

There are some additional complications regarding tracking when you try again. We record each message and its serial number (delivery label) with the tracker. But when we create a new channel to send messages again, all delivery labels are reset. But since we always have a MessageId, we can always fix the delivery tag.

Another thing to remember is that when a non-routable message is returned, BasicReturn is fired first, then an ACK is sent, and then BasicAck is fired. So if the current state is not routable, we need to make sure not to replace that state with Success(ack). This is done in MessageTracker.

(Video) RabbitMQ vs Kafka | Trade-off's to choose one over other | Tech Primers

Specify a custom header that is republished

When a replay is performed, we add a custom "reissue" header. It is not possible to avoid duplicate messages unless you are willing to accept the loss of messages, and removing duplicate messages also has many problems. Therefore, the best method to avoid duplicate message processing is to disable all message processing. This is not always possible as a default behavior due to performance (and budget) issues. Therefore, it may be useful to define a relayed header so that the consumer can apply insufficient logic only to messages that have either the relayed header or the relayed flag. These two are indicators that this is a double message.

Each message is wrapped in a MessageState class. One of its properties is SendCount. We increment this property before each call to BasicPublish. When we create the message, if SendCount is greater than 0, we add the "reissue" header.

Then, if all goes well, the messages will be sent and you will see how many succeeded, how many attempts were made and how many duplicate messages were created.

Note that it took 3 attempts due to the two connection errors. We reposted 164 messages that were never confirmed, 96 of which ended up as duplicates in the queue.

(Video) Streaming financial data with RabbitMQ | Piotr Stecko | TWF Conference 2017

However, he managed to send all 100,000 messages successfully.

Let's do it again, but this time we'll keep killing the connection until the iterations run out. In this example, I tried to send 500,000 in batches of 100 messages and had the connection close four times.

Therefore, performance degradation was not linear. There wasn't much between having one lot and a hundred lots. However, calling WaitForConfirms after each message was sent significantly reduced performance.

Next step

Play around with the code, do some debugging to see for yourself all the behavior of the C# RabbitMq client under different error scenarios. An additional scenario you can try is to set a message limit on the "" queue and send 100,000 messages. Everything will be shipped successfully and if you open the admin web console and see some messages, the OrderId property will be 90001 and above. The first 90,000 messages will be silently removed and discarded. Then try adding an exchange and dead letter queue and this time you will see 90,000 messages in the dead letter queue.

Emof the 3we will see how to handle messages that cannot be routed.


(Video) RabbitMQ & Kafka

I previously added code to handle out-of-order bindings, but after extensive testing I've found that there's nothing to worry about. So please ignore any of the comments in this thread.


How do I send bulk messages in RabbitMQ? ›

Just run the console application and it will create the exchange and queue required. Then you just enter: Number of messages to send. Exchange name - enter "order" if you want to test normal message sending and a different exchange name if you want to test a 404 no exchange error.

How does RabbitMQ push messages to consumers? ›

Applications can subscribe to have RabbitMQ push enqueued messages (deliveries) to them. This is done by registering a consumer (subscription) on a queue. After a subscription is in place, RabbitMQ will begin delivering messages. For each delivery a user-provided handler will be invoked.

How do I publish a message from API to RabbitMQ? ›

You can send an API request directly to RabbitMQ via api_req: Go to RabbitMQ → the Queues tab. Then select api_req and Publish message.

How many messages can RabbitMQ handle per second? ›

RabbitMQ is also used to convey a message to various recipients for consumption or to share loads between workers under high load (20K+ messages/second).

How do you send a lot of messages at once? ›

  1. Tap Android Messages.
  2. Tap Menu (3 dots in the top right corner)
  3. Tap Settings.
  4. Tap Advanced.
  5. Tap Group Messaging.
  6. Tap "Send an SMS reply to all recipients and get individual replies (mass text)"

How do I send bulk normal messages? ›

How can I send a bulk SMS?
  1. Grow an audience. To start, you'll need a contact list of recipients who have explicitly permitted you to message them. ...
  2. Find an SMS service provider. Next, you'll need to find an SMS service provider to help you send your bulk SMS message. ...
  3. Get a short code. ...
  4. Craft your message. ...
  5. Send it.

How do I track messages in RabbitMQ? ›

To actually trace messages a RabbitMQ user needs to bind a queue (this is the destination of the traced messages) to the amq. rabbitmq. trace exchange and use the appropriate routing key based on what we want to trace: # trace every message sent to any exchange and delivered by any queue.

What is the disadvantage of RabbitMQ? ›

RabbitMQ offers reliability, flexible routing, multiple exchange types, and easy deployment for enhanced messaging systems. RabbitMQ drawbacks: overly technical, limited queue visibility, and unclear error messages.

What are the downsides of RabbitMQ? ›

Cons of RabbitMQ Message Broker
  • Not reliable for large data sets but Kafka is excellent in processing large datasets.
  • Non-transactional (by default).
  • Needs Erlang.
  • Premium integration services.
  • Issues with processing big amounts of data.
Mar 16, 2022

How do I send an API response message? ›

  1. Select 'POST' as method.
  2. Add Content-Type header with the value 'application/json'
  3. Add the value which you want to add in the list in Body and press 'SEND' button.
  4. In the response header, you can see the http status code and message '201 Created'
Aug 22, 2019

How to send data to API using POST? ›

POSTing data to an API

POSTing data is done using the wp_remote_post() function, and takes exactly the same parameters as wp_remote_get() . To send data to the server you will need to build an associative array of data. This data will be assigned to the 'body' value.

How do I send a post request to API? ›

To make a POST request to an API endpoint, you need to send an HTTP POST request to the server and specify a Content-Type request header that specifies the data media type in the body of the POST API request. The Content-Length header indicates the data size in the POST message body.

What is the best practice for RabbitMQ connection? ›

RabbitMQ connections require at least 7 TCP packets for handshake. Channels can be opened and closed more frequently if needed. Best practice is to reuse connections and multiplex a connection between threads with channels.

Can RabbitMQ handle big messages? ›

Many messaging platforms have hard limits for message sizes. For example, RabbitMQ's maximum message size used to be 2GB, which later was changed to 512MB. You could split those large messages into multiple smaller chunks on the sender's end and later aggregate them on the receiver's end as a workaround.

Can Kafka replace RabbitMQ? ›

Deciding Between Kafka and RabbitMQ

While Kafka is best suited for big data use cases requiring the best throughput, RabbitMQ is perfect for low latency message delivery and complex routing. There are some common use cases for both Kafka and RabbitMQ.

How many messages can be sent in one day? ›

How many emails can you send from Gmail per day? For individual Gmail accounts, the daily send limit is 500 emails per rolling 24-hour period. If you're a typical Gmail user, you may not even know about this limit because it's doubtful you send that many emails in a typical day.

How do I send a message every day? ›

How to schedule a text message on Android
  1. Open Messages. Swipe up on the home screen and enter “Messages” in the search bar if the app isn't accessible.
  2. Compose your message. Tap Compose in the lower-right corner, then select your recipient and write your text.
  3. Schedule the message. ...
  4. Set a time and date.
Apr 28, 2023

How can I send bulk messages without adding contacts? ›

How To Send Bulk WhatsApp Message Without Adding Contact
  1. Quick Answer. You can use any WhatsApp marketing software like WASender and WAPlus to help you send bulk messages to as many numbers as you want. ...
  2. WAPlus Extension. You can try the WAPlus extension instead of WASender to send bulk messages on WhatsApp.
  3. Note.
Jan 2, 2023

How can I send bulk messages without getting banned? ›

You need to make sure that the contacts you are sending messages to have given you their consent. You can create a list of contacts by asking people to sign up for your newsletter or by asking them to join your WhatsApp group. Once you have a list of contacts, you can start sending bulk messages.

Is there a way to send emails in bulk? ›

Five best mass email senders for bulk email blasts
  1. Sendinblue. Sendinblue is an all-in-one email marketing service that offers excellent deliverability and lets you optimize your send time. ...
  2. SendGrid. ...
  3. Elastic Email. ...
  4. Amazon SES. ...
  5. Mailjet.
Sep 13, 2022

How do I fetch data from RabbitMQ? ›

In this article:
  1. Getting started.
  2. Prepare the infrastructure.
  3. Configure additional settings.
  4. Set up integration with RabbitMQ for the Managed Service for ClickHouse cluster.
  5. In the Managed Service for ClickHouse cluster, create a table on the RabbitMQ engine.
  6. Send the test data to the RabbitMQ queue.

How do I get metrics for RabbitMQ? ›

You can gather RabbitMQ metrics through a set of plugins and built-in tools. One is rabbitmqctl , a RabbitMQ command line interface that lists queues, exchanges, and so on, along with various metrics.

Is RabbitMQ used for messaging? ›

RabbitMQ is a messaging broker - an intermediary for messaging. It gives your applications a common platform to send and receive messages, and your messages a safe place to live until received.

Is Kafka faster than RabbitMQ? ›

Kafka generally has better performance. If you are looking for more throughput, Kafka can go up to around 1,000,000 messages per second, whereas the throughput for RabbitMQ is around 4K-10K messages per second. This is due to the architecture, as Kafka was designed around throughput.

Why use celery instead of RabbitMQ? ›

Celery and RabbitMQ belong to "Message Queue" category of the tech stack. "Task queue" is the primary reason why developers consider Celery over the competitors, whereas "It's fast and it works with good metrics/monitoring" was stated as the key factor in picking RabbitMQ.

How long do messages stay in RabbitMQ? ›

Message Queue for RabbitMQ:How long can messages be retained in Message Queue for RabbitMQ? Regardless of whether messages are consumed or fail to be consumed in Message Queue for RabbitMQ, messages can be retained for a maximum of three days.

How many clients can RabbitMQ handle? ›

Below is the default TCP socket option configuration used by RabbitMQ: TCP connection backlog is limited to 128 connections.

Can RabbitMQ lose messages? ›

RabbitMQ Durable queues are those that can withstand a RabbitMQ restart. If a queue is not durable, all messages will be lost if RabbitMQ is shut down for any reason.

Is RabbitMQ SQL or NoSql? ›

RabbitMQ is a message broker software aka a queue and not a NoSql database!

How do I fetch API responses? ›

The Fetch API allows you to asynchronously request for a resource. Use the fetch() method to return a promise that resolves into a Response object. To get the actual data, you call one of the methods of the Response object e.g., text() or json() . These methods resolve into the actual data.

How do I map an API response? ›

  1. Open the GET /items Operation flow diagram as described in Mapping your API and z/OS Assets. An amber exclamation mark. ...
  2. Map the 200 response. In the Operation flow diagram, click the 200 response node. ...
  3. Map the remaining API response fields. ...
  4. Map the 500 - Internal Server Error response.

What is the difference between response text and response JSON? ›

In that case, the difference is that ". text()" will give you the result in string format, and ". json()" will parse it from JSON and convert it into an object.

What is the difference between GET API and POST API? ›

Difference between GET and POST Method in API

No limit on data length is there in POST request. Get is simple to use because of its nature of appending data to URL only. Post requires header information, body, etc which makes it hard to use as compared with Get request. Get requestsrequest can be cached.

How to send JSON data in POST request? ›

Let's see the steps now.
  1. Select POST request and enter your service POST operation URL.
  2. Click on Headers. In the key column enter Content-Type and in the Value column enter application/json .
  3. Click on the body section and click the raw radio button. enter your JSON data. Click the Send button.
May 14, 2021

How do I send JSON data to an API? ›

To post JSON to a REST API endpoint, you must send an HTTP POST request to the REST API server and provide JSON data in the body of the POST message. You must also specify the data type using the Content-Type: application/json request header.

How do I send HTTP POST request to server? ›

To send data using the HTTP POST method, you must include the data in the body of the HTTP POST message and specify the MIME type of the data with a Content-Type header. Below is an example of an HTTP POST request to send JSON data to the server. The size and data type for HTTP POST requests is not limited.

How do I send a POST request to API using Postman? ›

Create a POST Request
  1. Step 1 − Click on the New menu from the Postman application. ...
  2. Step 2 − SAVE REQUEST pop-up comes up. ...
  3. Step 3 − The Request name (Test1) gets reflected on the Request tab. ...
  4. Step 4 − Move to the Body tab below the address bar and select the option raw.
  5. Step 5 − Then, choose JSON from the Text dropdown.

How do I send an API gateway request? ›

Create a request in API Gateway Explorer

Enter the details for the request that you wish to execute in the Add Request Configuration dialog (for example: http://localhost:8080/conversion ). If the Request name matches URL setting is not selected, you can supply a custom Request Name for this request.

Does RabbitMQ need a load balancer? ›

RabbitMQ does not require session affinity at the load balancing layer by default. To provide load balancing and high-availability for RabbitMQ, one virtual service is required. The virtual service must be set to listen on the same port as the RabbitMQ service, which listens on port 5672 by default.

How much traffic can RabbitMQ handle? ›

Use multiple queues and consumers

Queues are single-threaded in RabbitMQ, and one queue can handle up to about 50 thousand messages. You will achieve better throughput on a multi-core system if you have multiple queues and consumers and if you have as many queues as cores on the underlying node(s).

What is the difference between channel and connection in RabbitMQ? ›

A connection is a TCP connection between your application and the RabbitMQ broker. A channel is a virtual connection inside a connection. In other words, a channel multiplexes a TCP connection. Typically, each process only creates one TCP connection, and uses multiple channels in that connection for different threads.

How many messages can RabbitMQ process? ›

RabbitMQ can have a maximum of 50 000 messages per queue. There is no this kind of limit. RabbitMQ can handle more messages using quorum or classic queues with lazy. With stream queues RabbitMQ can handle Millions of messages per second.

How do I send a message to all consumers in RabbitMQ? ›

To have each consumer receive the same message, you need to create a queue for each consumer and deliver the same message to each queue. The easiest way to do this is to use a fanout exchange. This will send every message to every queue that is bound to the exchange, completely ignoring the routing key.

Can RabbitMQ push messages? ›

Applications can subscribe to have RabbitMQ push enqueued messages (deliveries) to them. This is done by registering a consumer (subscription) on a queue. After a subscription is in place, RabbitMQ will begin delivering messages. For each delivery a user-provided handler will be invoked.

Is RabbitMQ push or pull? ›

RabbitMQ: Push-based approach

RabbitMQ uses a push-based model with a smart producer, which means the producer decides when to push data. A prefetch limit is defined on the consumer to stop the producer from overwhelming consumers. Such a push-based approach is suited for low latency messaging.

Can Kafka replace MQ? ›

As a conventional Message Queue, IBM MQ has more features than Kafka. IBM MQ also supports JMS, making it a more convenient alternative to Kafka. Kafka, on the other side, is better suited to large data frameworks such as Lambda. Kafka also has connectors and provides stream processing.

Is it possible that multiple consumers of a RabbitMQ queue get the same message? ›

RabbitMQ has a plugin for consistent hash exchange. Using that exchange, and one consumer per queue, we can achieve message order with multiple consumers. The hash exchange distributes routing keys among queues, instead of messages among queues. This means all messages with the same routing key will go the same queue.

Is it possible to send bulk SMS? ›

Bulk SMS Plans

Bulk SMS Plans is another SMS solution that gives you many interactive features. It lets you send your custom text to up to 5,000 contacts with a single tap.

What is the limitation of RabbitMQ? ›

The maximum number of connections per instance is 10,000. Purchase a quota for the number of connections that are required for each instance based on instance specifications. A free quota of 50,000 connections is provided for a single instance. The maximum number of connections per instance is 100,000.

Can a Message Queue have multiple consumers? ›

More than one receiver can consume messages from a queue, but each message can be consumed by only one receiver. Thus Msg1, Msg2, and Msg3 are consumed by different receivers. (This is a Message Queue extension.)

What is the message limitation in RabbitMQ? ›

While the theoretical message size limit in RabbitMQ is 2GB up to 3.7. 0, we don't recommend sending messages larger than 128MB, which is also the new max size limit in 3.8. 0 and onward. Large messages are especially problematic when using mirrored queues in HA clusters and can cause memory and performance issues.

How do you send a mass message without a group chat? ›

How to send text to multiple contacts without group message through Android
  1. Open your phone's default text messaging app.
  2. Tap on 'new message' or '+' according to your phone's design.
  3. In the recipient box, add all the contacts you wish to send the message to.
  4. Add the message.
  5. Hit Send.

How much load can RabbitMQ handle? ›

The RabbitMQ default prefetch setting gives clients an unlimited buffer, meaning that RabbitMQ by default sends as many messages as it can to any consumer that looks ready to accept them.

Which is better for message ordering Kafka or RabbitMQ? ›

RabbitMQ sends messages to users. These messages are removed from the queue once they are processed and acknowledged. Kafka is a log. It uses continuous messages, which stay in the queue until the retention time expires.

How can I send 1000 texts at once? ›

If you want to send 1000 SMS at a time free online or Send 1000 text messages at once in bulk or in a different country, you may use our service. Sending international SMS from India is easy with GetItSMS since we have the cheapest rates for sending international SMS from India.

How effective is bulk SMS? ›

Bulk SMS is a very useful and effective marketing channel that should be an integral part of any mobile marketing strategy that tends to achieve real success in today's mobile world.


1. RabbitMQ vs Kafka - Jack Vanlightly x Erlang Solutions webinar
(Erlang Solutions)
2. Message Routing- A Next-Generation Alternative to RabbitMQ
(OpenInfra Foundation)
3. Autoscaling Kubernetes using RabbitMQ
(Daniel Persson)
4. Running RabbitMQ at Scale - Lovisa Johansson & Anders Bälter
(RabbitMQ Summit)
5. Learnings from Running 1000s of Production RabbitMQ Clusters • Lovisa Johansson • RabbitMQ Summit
(GOTO Conferences)
6. Keynote: Idiomatic RabbitMQ - Gavin M Roy
(RabbitMQ Summit)


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